From 28fab80ed42dcdf56bac22f67b6e262e3ad54cd2 Mon Sep 17 00:00:00 2001
From: Hanzhen Yi <33737743+hzyi-google@users.noreply.github.com>
Date: Tue, 6 Nov 2018 16:38:35 -0800
Subject: [PATCH] Spanner gapic migration (#3881)

* Add GapicSpannerRpc stub (#3016)

* spanner: implement partitionRead (#3022)

* spanner: implement LRO methods using GAPIC stub (#3039)

* Add implementation to:listInstances, listInstanceConfigs, listDatabases, getInstance, getInstanceConfigs, getDatabase, dropDatabase, deleteInstance, getDatabaseDdl  (#3043)

* spanner: move admin clients to GAPIC stub (#3067)

* Spanner: migrate all unary call methods to gapic and inject headers (#3112)

* Spanner: migrate streaming methods to gapic (#3139)

* Spanner gapic migration lro methods (#3166)

Migrate longrunning methods to GAPIC including: createDatabase, updateDatabaseDdl, createInstance, and updateInstance.

* Make ChannelPool work (#3258)

* Spanner gapic migration error augmentation with interceptor (#3304)

* Add interceptors (#3346)

* Clean up Spanner before merging to master (#3362)

* Spanner Gapic Migration: fix updateDatabaseDdl (#3403)
---
 .../com/google/cloud/spanner/Database.java    |   3 +-
 .../cloud/spanner/DatabaseAdminClient.java    |  19 +-
 .../com/google/cloud/spanner/Instance.java    |   5 +-
 .../cloud/spanner/InstanceAdminClient.java    |  39 +-
 .../com/google/cloud/spanner/SpannerImpl.java | 253 ++++---
 .../google/cloud/spanner/SpannerOptions.java  | 190 ++---
 .../cloud/spanner/spi/v1/GapicSpannerRpc.java | 585 +++++++++++++++
 .../cloud/spanner/spi/v1/GrpcSpannerRpc.java  | 684 ------------------
 .../spanner/spi/v1/LoggingInterceptor.java    | 108 +++
 .../spi/v1/SpannerInterceptorProvider.java    |  62 ++
 .../spi/v1/SpannerMetadataProvider.java       |  22 +-
 .../cloud/spanner/spi/v1/SpannerRpc.java      |  22 +-
 .../spanner/testing/RemoteSpannerHelper.java  |  22 +-
 .../cloud/spanner/BatchClientImplTest.java    |  13 +-
 .../spanner/DatabaseAdminClientImplTest.java  |  55 +-
 .../cloud/spanner/GceTestEnvConfig.java       |   9 +-
 .../spanner/InstanceAdminClientImplTest.java  |  35 +-
 .../cloud/spanner/IntegrationTestEnv.java     |  15 +-
 .../cloud/spanner/OperationFutureUtil.java    | 275 +++++++
 .../cloud/spanner/SpannerOptionsTest.java     |  24 +-
 .../cloud/spanner/it/ITDatabaseAdminTest.java |  39 +-
 .../cloud/spanner/it/ITInstanceAdminTest.java |  14 +-
 .../spanner/spi/v1/RequestMetadataTest.java   |  70 --
 .../spi/v1/SpannerMetadataProviderTest.java   |  13 +
 .../snippets/DatabaseAdminClientSnippets.java |  26 +-
 .../snippets/InstanceAdminClientSnippets.java |  25 +-
 26 files changed, 1474 insertions(+), 1153 deletions(-)
 create mode 100644 google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GapicSpannerRpc.java
 delete mode 100644 google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GrpcSpannerRpc.java
 create mode 100644 google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/LoggingInterceptor.java
 create mode 100644 google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/SpannerInterceptorProvider.java
 create mode 100644 google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/OperationFutureUtil.java
 delete mode 100644 google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/spi/v1/RequestMetadataTest.java

diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/Database.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/Database.java
index bee2dd1b96fd..97894ae12cec 100644
--- a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/Database.java
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/Database.java
@@ -18,6 +18,7 @@
 
 import static com.google.common.base.Preconditions.checkArgument;
 
+import com.google.api.gax.longrunning.OperationFuture;
 import com.google.spanner.admin.database.v1.UpdateDatabaseDdlMetadata;
 
 /**
@@ -51,7 +52,7 @@ public Database reload() throws SpannerException {
    *     one. This must be unique within a database abd must be a valid identifier
    *     [a-zA-Z][a-zA-Z0-9_]*.
    */
-  public Operation<Void, UpdateDatabaseDdlMetadata> updateDdl(
+  public OperationFuture<Void, UpdateDatabaseDdlMetadata> updateDdl(
       Iterable<String> statements, String operationId) throws SpannerException {
     return dbClient.updateDatabaseDdl(instance(), database(), statements, operationId);
   }
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/DatabaseAdminClient.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/DatabaseAdminClient.java
index f4bf86de11d1..9662cc9050bc 100644
--- a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/DatabaseAdminClient.java
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/DatabaseAdminClient.java
@@ -16,6 +16,7 @@
 
 package com.google.cloud.spanner;
 
+import com.google.api.gax.longrunning.OperationFuture;
 import com.google.api.gax.paging.Page;
 import com.google.cloud.spanner.Options.ListOption;
 import com.google.spanner.admin.database.v1.CreateDatabaseMetadata;
@@ -29,7 +30,8 @@ public interface DatabaseAdminClient {
    * Creates a new database in a Cloud Spanner instance.
    *
    * <p>Example to create database.
-   * <pre> {@code
+   *
+   * <pre>{@code
    * String instanceId = my_instance_id;
    * String databaseId = my_database_id;
    * Operation<Database, CreateDatabaseMetadata> op = dbAdminClient
@@ -58,19 +60,19 @@ public interface DatabaseAdminClient {
    * @param statements DDL statements to run while creating the database, for example {@code CREATE
    *     TABLE MyTable ( ... )}. This should not include {@code CREATE DATABASE} statement.
    */
-  Operation<Database, CreateDatabaseMetadata> createDatabase(
+  OperationFuture<Database, CreateDatabaseMetadata> createDatabase(
       String instanceId, String databaseId, Iterable<String> statements) throws SpannerException;
 
-  /** 
-   * Gets the current state of a Cloud Spanner database. 
+  /**
+   * Gets the current state of a Cloud Spanner database.
    *
    * <p>Example to getDatabase.
-   * <pre> {@code
+   *
+   * <pre>{@code
    * String instanceId = my_instance_id;
    * String databaseId = my_database_id;
    * Database db = dbAdminClient.getDatabase(instanceId, databaseId);
    * }</pre>
-   *
    */
   Database getDatabase(String instanceId, String databaseId) throws SpannerException;
 
@@ -84,7 +86,8 @@ Operation<Database, CreateDatabaseMetadata> createDatabase(
    * fails, all subsequent statements in the batch are automatically cancelled.
    *
    * <p>Example to update the database DDL.
-   * <pre> {@code
+   *
+   * <pre>{@code
    * String instanceId = my_instance_id;
    * String databaseId = my_database_id;
    * dbAdminClient.updateDatabaseDdl(instanceId,
@@ -97,7 +100,7 @@ Operation<Database, CreateDatabaseMetadata> createDatabase(
    *     one. This must be unique within a database abd must be a valid identifier
    *     [a-zA-Z][a-zA-Z0-9_]*.
    */
-  Operation<Void, UpdateDatabaseDdlMetadata> updateDatabaseDdl(
+  OperationFuture<Void, UpdateDatabaseDdlMetadata> updateDatabaseDdl(
       String instanceId,
       String databaseId,
       Iterable<String> statements,
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/Instance.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/Instance.java
index a1dc71362202..c8f92bf2111a 100644
--- a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/Instance.java
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/Instance.java
@@ -16,6 +16,7 @@
 
 package com.google.cloud.spanner;
 
+import com.google.api.gax.longrunning.OperationFuture;
 import com.google.api.gax.paging.Page;
 import com.google.spanner.admin.database.v1.CreateDatabaseMetadata;
 import com.google.spanner.admin.instance.v1.UpdateInstanceMetadata;
@@ -104,7 +105,7 @@ public void delete() {
     instanceClient.deleteInstance(instanceId());
   }
 
-  public Operation<Instance, UpdateInstanceMetadata> update(
+  public OperationFuture<Instance, UpdateInstanceMetadata> update(
       InstanceInfo.InstanceField... fieldsToUpdate) {
     return instanceClient.updateInstance(this, fieldsToUpdate);
   }
@@ -125,7 +126,7 @@ public Database getDatabase(String databaseId) {
    * @param statements DDL statements to run while creating the database, for example {@code CREATE
    *     TABLE MyTable ( ... )}. This should not include {@code CREATE DATABASE} statement.
    */
-  public Operation<Database, CreateDatabaseMetadata> createDatabase(
+  public OperationFuture<Database, CreateDatabaseMetadata> createDatabase(
       String databaseId, Iterable<String> statements) throws SpannerException {
     return dbClient.createDatabase(instanceId(), databaseId, statements);
   }
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/InstanceAdminClient.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/InstanceAdminClient.java
index 4a046cc40c9f..b5760ef377fc 100644
--- a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/InstanceAdminClient.java
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/InstanceAdminClient.java
@@ -16,6 +16,7 @@
 
 package com.google.cloud.spanner;
 
+import com.google.api.gax.longrunning.OperationFuture;
 import com.google.api.gax.paging.Page;
 import com.google.cloud.spanner.Options.ListOption;
 import com.google.spanner.admin.instance.v1.CreateInstanceMetadata;
@@ -51,29 +52,30 @@ public interface InstanceAdminClient {
    * upon completion of this request:
    *
    * <ul>
-   *   <li> The instance is readable via the API, with all requested attributes but no allocated
+   *   <li>The instance is readable via the API, with all requested attributes but no allocated
    *       resources.
-   *   <li> Its state is {@code CREATING}.
+   *   <li>Its state is {@code CREATING}.
    * </ul>
    *
    * Until completion of the returned operation:
    *
    * <ul>
-   *   <li> Cancelling the operation renders the instance immediately unreadable via the API.
-   *   <li> The instance can be deleted.
-   *   <li> All other attempts to modify the instance are rejected.
+   *   <li>Cancelling the operation renders the instance immediately unreadable via the API.
+   *   <li>The instance can be deleted.
+   *   <li>All other attempts to modify the instance are rejected.
    * </ul>
    *
    * Upon completion of the returned operation:
    *
    * <ul>
-   *   <li> Billing for all successfully-allocated resources begins (some types may have lower than
+   *   <li>Billing for all successfully-allocated resources begins (some types may have lower than
    *       the requested levels).
-   *   <li> Databases can be created in the instance.
-   *   <li> The instance's allocated resource levels are readable via the
+   *   <li>Databases can be created in the instance.
+   *   <li>The instance's allocated resource levels are readable via the
    * </ul>
    *
    * <!--SNIPPET instance_admin_client_create_instance-->
+   *
    * <pre>{@code
    * final String instanceId = my_instance_id;
    * final String configId = my_config_id;
@@ -88,9 +90,10 @@ public interface InstanceAdminClient {
    *         .build());
    * op.waitFor();
    * }</pre>
+   *
    * <!--SNIPPET instance_admin_client_create_instance-->
    */
-  Operation<Instance, CreateInstanceMetadata> createInstance(InstanceInfo instance)
+  OperationFuture<Instance, CreateInstanceMetadata> createInstance(InstanceInfo instance)
       throws SpannerException;
 
   /** Gets an instance. */
@@ -142,31 +145,32 @@ Operation<Instance, CreateInstanceMetadata> createInstance(InstanceInfo instance
    * <p>Immediately upon completion of this request:
    *
    * <ul>
-   *   <li> For resource types for which a decrease in the instance's allocation has been requested,
+   *   <li>For resource types for which a decrease in the instance's allocation has been requested,
    *       billing is based on the newly-requested level.
    * </ul>
    *
    * Until completion of the returned operation:
    *
    * <ul>
-   *   <li> Cancelling the operation sets its metadata's
+   *   <li>Cancelling the operation sets its metadata's
    *       [cancel_time][UpdateInstanceMetadata.cancel_time], and begins restoring resources to
    *       their pre-request values. The operation is guaranteed to succeed at undoing all resource
    *       changes, after which point it terminates with a `CANCELLED` status.
-   *   <li> All other attempts to modify the instance are rejected.
-   *   <li> Reading the instance via the API continues to give the pre-request resource levels.
+   *   <li>All other attempts to modify the instance are rejected.
+   *   <li>Reading the instance via the API continues to give the pre-request resource levels.
    * </ul>
    *
    * Upon completion of the returned operation:
    *
    * <ul>
-   *   <li> Billing begins for all successfully-allocated resources (some types may have lower than
+   *   <li>Billing begins for all successfully-allocated resources (some types may have lower than
    *       the requested levels).
-   *   <li> All newly-reserved resources are available for serving the instance's tables.
-   *   <li> The instance's new resource levels are readable via the API.
+   *   <li>All newly-reserved resources are available for serving the instance's tables.
+   *   <li>The instance's new resource levels are readable via the API.
    * </ul>
    *
    * <!--SNIPPET instance_admin_client_update_instance-->
+   *
    * <pre>{@code
    * Instance instance = my_instance;
    * final String clientProject = my_client_project;
@@ -184,9 +188,10 @@ Operation<Instance, CreateInstanceMetadata> createInstance(InstanceInfo instance
    *     instanceAdminClient.updateInstance(toUpdate, InstanceInfo.InstanceField.DISPLAY_NAME);
    * op.waitFor().getResult();
    * }</pre>
+   *
    * <!--SNIPPET instance_admin_client_update_instance-->
    */
-  Operation<Instance, UpdateInstanceMetadata> updateInstance(
+  OperationFuture<Instance, UpdateInstanceMetadata> updateInstance(
       InstanceInfo instance, InstanceInfo.InstanceField... fieldsToUpdate);
 
   /** Returns a builder for {@code Instance} object with the given id. */
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerImpl.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerImpl.java
index d89471a2b8de..ff5a0f481958 100644
--- a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerImpl.java
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerImpl.java
@@ -24,7 +24,13 @@
 
 import com.google.api.client.util.BackOff;
 import com.google.api.client.util.ExponentialBackOff;
+import com.google.api.core.ApiFunction;
+import com.google.api.gax.grpc.ProtoOperationTransformers;
+import com.google.api.gax.longrunning.OperationFuture;
+import com.google.api.gax.longrunning.OperationFutureImpl;
+import com.google.api.gax.longrunning.OperationSnapshot;
 import com.google.api.gax.paging.Page;
+import com.google.api.gax.rpc.ServerStream;
 import com.google.api.pathtemplate.PathTemplate;
 import com.google.cloud.BaseService;
 import com.google.cloud.ByteArray;
@@ -32,7 +38,6 @@
 import com.google.cloud.PageImpl;
 import com.google.cloud.PageImpl.NextPageFetcher;
 import com.google.cloud.Timestamp;
-import com.google.cloud.spanner.Operation.Parser;
 import com.google.cloud.spanner.Options.ListOption;
 import com.google.cloud.spanner.Options.QueryOption;
 import com.google.cloud.spanner.Options.ReadOption;
@@ -51,6 +56,7 @@
 import com.google.common.util.concurrent.Uninterruptibles;
 import com.google.protobuf.Any;
 import com.google.protobuf.ByteString;
+import com.google.protobuf.Empty;
 import com.google.protobuf.FieldMask;
 import com.google.protobuf.InvalidProtocolBufferException;
 import com.google.protobuf.ListValue;
@@ -75,7 +81,6 @@
 import com.google.spanner.v1.TransactionSelector;
 import com.google.spanner.v1.TypeCode;
 import io.grpc.Context;
-import io.grpc.ManagedChannel;
 import io.opencensus.common.Scope;
 import io.opencensus.trace.AttributeValue;
 import io.opencensus.trace.Span;
@@ -147,7 +152,7 @@ private static void throwIfTransactionsPending() {
   }
 
   private final Random random = new Random();
-  private final SpannerRpc rpc;
+  private final SpannerRpc gapicRpc;
   private final int defaultPrefetchChunks;
 
   @GuardedBy("this")
@@ -159,12 +164,13 @@ private static void throwIfTransactionsPending() {
   @GuardedBy("this")
   private boolean spannerIsClosed = false;
 
-  SpannerImpl(SpannerRpc rpc, int defaultPrefetchChunks, SpannerOptions options) {
+  SpannerImpl(SpannerRpc gapicRpc, int defaultPrefetchChunks, SpannerOptions options) {
     super(options);
-    this.rpc = rpc;
+    this.gapicRpc = gapicRpc;
     this.defaultPrefetchChunks = defaultPrefetchChunks;
-    this.dbAdminClient = new DatabaseAdminClientImpl(options.getProjectId(), rpc);
-    this.instanceClient = new InstanceAdminClientImpl(options.getProjectId(), rpc, dbAdminClient);
+    this.dbAdminClient = new DatabaseAdminClientImpl(options.getProjectId(), gapicRpc);
+    this.instanceClient =
+        new InstanceAdminClientImpl(options.getProjectId(), gapicRpc, dbAdminClient);
   }
 
   SpannerImpl(SpannerOptions options) {
@@ -268,7 +274,8 @@ Session createSession(final DatabaseId db) throws SpannerException {
               new Callable<com.google.spanner.v1.Session>() {
                 @Override
                 public com.google.spanner.v1.Session call() throws Exception {
-                  return rpc.createSession(db.getName(), getOptions().getSessionLabels(), options);
+                  return gapicRpc.createSession(
+                      db.getName(), getOptions().getSessionLabels(), options);
                 }
               });
       span.end();
@@ -332,12 +339,10 @@ public void close() {
     } catch (InterruptedException | ExecutionException e) {
       throw SpannerExceptionFactory.newSpannerException(e);
     }
-    for (ManagedChannel channel : getOptions().getRpcChannels()) {
-      try {
-        channel.shutdown();
-      } catch (RuntimeException e) {
-        logger.log(Level.WARNING, "Failed to close channel", e);
-      }
+    try {
+      gapicRpc.shutdown();
+    } catch (RuntimeException e) {
+      logger.log(Level.WARNING, "Failed to close channels", e);
     }
   }
 
@@ -440,27 +445,31 @@ static class DatabaseAdminClientImpl implements DatabaseAdminClient {
     }
 
     @Override
-    public Operation<Database, CreateDatabaseMetadata> createDatabase(
+    public OperationFuture<Database, CreateDatabaseMetadata> createDatabase(
         String instanceId, String databaseId, Iterable<String> statements) throws SpannerException {
       // CreateDatabase() is not idempotent, so we're not retrying this request.
       String instanceName = getInstanceName(instanceId);
       String createStatement = "CREATE DATABASE `" + databaseId + "`";
-      com.google.longrunning.Operation op =
-          rpc.createDatabase(instanceName, createStatement, statements);
-      return Operation.create(
-          rpc,
-          op,
-          new Parser<Database, CreateDatabaseMetadata>() {
+      OperationFuture<com.google.spanner.admin.database.v1.Database, CreateDatabaseMetadata>
+          rawOperationFuture = rpc.createDatabase(instanceName, createStatement, statements);
+      return new OperationFutureImpl(
+          rawOperationFuture.getPollingFuture(),
+          rawOperationFuture.getInitialFuture(),
+          new ApiFunction<OperationSnapshot, Database>() {
             @Override
-            public Database parseResult(Any response) {
+            public Database apply(OperationSnapshot snapshot) {
               return Database.fromProto(
-                  unpack(response, com.google.spanner.admin.database.v1.Database.class),
+                  ProtoOperationTransformers.ResponseTransformer.create(
+                          com.google.spanner.admin.database.v1.Database.class)
+                      .apply(snapshot),
                   DatabaseAdminClientImpl.this);
             }
-
+          },
+          ProtoOperationTransformers.MetadataTransformer.create(CreateDatabaseMetadata.class),
+          new ApiFunction<Exception, Database>() {
             @Override
-            public CreateDatabaseMetadata parseMetadata(Any metadata) {
-              return unpack(metadata, CreateDatabaseMetadata.class);
+            public Database apply(Exception e) {
+              throw SpannerExceptionFactory.newSpannerException(e);
             }
           });
     }
@@ -479,7 +488,7 @@ public Database call() throws Exception {
     }
 
     @Override
-    public Operation<Void, UpdateDatabaseDdlMetadata> updateDatabaseDdl(
+    public OperationFuture<Void, UpdateDatabaseDdlMetadata> updateDatabaseDdl(
         final String instanceId,
         final String databaseId,
         final Iterable<String> statements,
@@ -487,47 +496,24 @@ public Operation<Void, UpdateDatabaseDdlMetadata> updateDatabaseDdl(
         throws SpannerException {
       final String dbName = getDatabaseName(instanceId, databaseId);
       final String opId = operationId != null ? operationId : randomOperationId();
-      Callable<Operation<Void, UpdateDatabaseDdlMetadata>> callable =
-          new Callable<Operation<Void, UpdateDatabaseDdlMetadata>>() {
+      OperationFuture<Empty, UpdateDatabaseDdlMetadata> rawOperationFuture =
+          rpc.updateDatabaseDdl(dbName, statements, opId);
+      return new OperationFutureImpl(
+          rawOperationFuture.getPollingFuture(),
+          rawOperationFuture.getInitialFuture(),
+          new ApiFunction<OperationSnapshot, Void>() {
             @Override
-            public Operation<Void, UpdateDatabaseDdlMetadata> call() {
-              com.google.longrunning.Operation op = null;
-              try {
-                op = rpc.updateDatabaseDdl(dbName, statements, opId);
-              } catch (SpannerException e) {
-                if (e.getErrorCode() == ErrorCode.ALREADY_EXISTS) {
-                  String opName =
-                      OP_NAME_TEMPLATE.instantiate(
-                          "project",
-                          projectId,
-                          "instance",
-                          instanceId,
-                          "database",
-                          databaseId,
-                          "operation",
-                          opId);
-                  op = com.google.longrunning.Operation.newBuilder().setName(opName).build();
-                } else {
-                  throw e;
-                }
-              }
-              return Operation.create(
-                  rpc,
-                  op,
-                  new Parser<Void, UpdateDatabaseDdlMetadata>() {
-                    @Override
-                    public Void parseResult(Any response) {
-                      return null;
-                    }
-
-                    @Override
-                    public UpdateDatabaseDdlMetadata parseMetadata(Any metadata) {
-                      return unpack(metadata, UpdateDatabaseDdlMetadata.class);
-                    }
-                  });
+            public Void apply(OperationSnapshot snapshot) {
+              return null;
             }
-          };
-      return runWithRetries(callable);
+          },
+          ProtoOperationTransformers.MetadataTransformer.create(UpdateDatabaseDdlMetadata.class),
+          new ApiFunction<Exception, Database>() {
+            @Override
+            public Database apply(Exception e) {
+              throw SpannerExceptionFactory.newSpannerException(e);
+            }
+          });
     }
 
     @Override
@@ -643,26 +629,32 @@ public InstanceConfig fromProto(
     }
 
     @Override
-    public Operation<Instance, CreateInstanceMetadata> createInstance(InstanceInfo instance)
+    public OperationFuture<Instance, CreateInstanceMetadata> createInstance(InstanceInfo instance)
         throws SpannerException {
       String projectName = PROJECT_NAME_TEMPLATE.instantiate("project", projectId);
-      com.google.longrunning.Operation op =
-          rpc.createInstance(projectName, instance.getId().getInstance(), instance.toProto());
-      return Operation.create(
-          rpc,
-          op,
-          new Parser<Instance, CreateInstanceMetadata>() {
+      OperationFuture<com.google.spanner.admin.instance.v1.Instance, CreateInstanceMetadata>
+          rawOperationFuture =
+              rpc.createInstance(projectName, instance.getId().getInstance(), instance.toProto());
+
+      return new OperationFutureImpl<Instance, CreateInstanceMetadata>(
+          rawOperationFuture.getPollingFuture(),
+          rawOperationFuture.getInitialFuture(),
+          new ApiFunction<OperationSnapshot, Instance>() {
             @Override
-            public Instance parseResult(Any response) {
+            public Instance apply(OperationSnapshot snapshot) {
               return Instance.fromProto(
-                  unpack(response, com.google.spanner.admin.instance.v1.Instance.class),
+                  ProtoOperationTransformers.ResponseTransformer.create(
+                          com.google.spanner.admin.instance.v1.Instance.class)
+                      .apply(snapshot),
                   InstanceAdminClientImpl.this,
                   dbClient);
             }
-
+          },
+          ProtoOperationTransformers.MetadataTransformer.create(CreateInstanceMetadata.class),
+          new ApiFunction<Exception, Instance>() {
             @Override
-            public CreateInstanceMetadata parseMetadata(Any metadata) {
-              return unpack(metadata, CreateInstanceMetadata.class);
+            public Instance apply(Exception e) {
+              throw SpannerExceptionFactory.newSpannerException(e);
             }
           });
     }
@@ -717,28 +709,34 @@ public Void call() {
     }
 
     @Override
-    public Operation<Instance, UpdateInstanceMetadata> updateInstance(
+    public OperationFuture<Instance, UpdateInstanceMetadata> updateInstance(
         InstanceInfo instance, InstanceInfo.InstanceField... fieldsToUpdate) {
       FieldMask fieldMask =
           fieldsToUpdate.length == 0
               ? InstanceInfo.InstanceField.toFieldMask(InstanceInfo.InstanceField.values())
               : InstanceInfo.InstanceField.toFieldMask(fieldsToUpdate);
-      com.google.longrunning.Operation op = rpc.updateInstance(instance.toProto(), fieldMask);
-      return Operation.create(
-          rpc,
-          op,
-          new Parser<Instance, UpdateInstanceMetadata>() {
+
+      OperationFuture<com.google.spanner.admin.instance.v1.Instance, UpdateInstanceMetadata>
+          rawOperationFuture = rpc.updateInstance(instance.toProto(), fieldMask);
+      return new OperationFutureImpl<Instance, UpdateInstanceMetadata>(
+          rawOperationFuture.getPollingFuture(),
+          rawOperationFuture.getInitialFuture(),
+          new ApiFunction<OperationSnapshot, Instance>() {
             @Override
-            public Instance parseResult(Any response) {
+            public Instance apply(OperationSnapshot snapshot) {
               return Instance.fromProto(
-                  unpack(response, com.google.spanner.admin.instance.v1.Instance.class),
+                  ProtoOperationTransformers.ResponseTransformer.create(
+                          com.google.spanner.admin.instance.v1.Instance.class)
+                      .apply(snapshot),
                   InstanceAdminClientImpl.this,
                   dbClient);
             }
-
+          },
+          ProtoOperationTransformers.MetadataTransformer.create(UpdateInstanceMetadata.class),
+          new ApiFunction<Exception, Instance>() {
             @Override
-            public UpdateInstanceMetadata parseMetadata(Any metadata) {
-              return unpack(metadata, UpdateInstanceMetadata.class);
+            public Instance apply(Exception e) {
+              throw SpannerExceptionFactory.newSpannerException(e);
             }
           });
     }
@@ -772,7 +770,7 @@ public String getName() {
     @Override
     public long executePartitionedUpdate(Statement stmt) {
       setActive(null);
-      PartitionedDMLTransaction txn = new PartitionedDMLTransaction(this, rpc);
+      PartitionedDMLTransaction txn = new PartitionedDMLTransaction(this, gapicRpc);
       return txn.executePartitionedUpdate(stmt);
     }
 
@@ -814,7 +812,7 @@ public Timestamp writeAtLeastOnce(Iterable<Mutation> mutations) throws SpannerEx
                 new Callable<CommitResponse>() {
                   @Override
                   public CommitResponse call() throws Exception {
-                    return rpc.commit(request, options);
+                    return gapicRpc.commit(request, options);
                   }
                 });
         Timestamp t = Timestamp.fromProto(response.getCommitTimestamp());
@@ -836,7 +834,7 @@ public ReadContext singleUse() {
 
     @Override
     public ReadContext singleUse(TimestampBound bound) {
-      return setActive(new SingleReadContext(this, bound, rpc, defaultPrefetchChunks));
+      return setActive(new SingleReadContext(this, bound, gapicRpc, defaultPrefetchChunks));
     }
 
     @Override
@@ -846,7 +844,8 @@ public ReadOnlyTransaction singleUseReadOnlyTransaction() {
 
     @Override
     public ReadOnlyTransaction singleUseReadOnlyTransaction(TimestampBound bound) {
-      return setActive(new SingleUseReadOnlyTransaction(this, bound, rpc, defaultPrefetchChunks));
+      return setActive(
+          new SingleUseReadOnlyTransaction(this, bound, gapicRpc, defaultPrefetchChunks));
     }
 
     @Override
@@ -856,12 +855,13 @@ public ReadOnlyTransaction readOnlyTransaction() {
 
     @Override
     public ReadOnlyTransaction readOnlyTransaction(TimestampBound bound) {
-      return setActive(new MultiUseReadOnlyTransaction(this, bound, rpc, defaultPrefetchChunks));
+      return setActive(
+          new MultiUseReadOnlyTransaction(this, bound, gapicRpc, defaultPrefetchChunks));
     }
 
     @Override
     public TransactionRunner readWriteTransaction() {
-      return setActive(new TransactionRunnerImpl(this, rpc, defaultPrefetchChunks));
+      return setActive(new TransactionRunnerImpl(this, gapicRpc, defaultPrefetchChunks));
     }
 
     @Override
@@ -878,7 +878,7 @@ public void close() {
             new Callable<Void>() {
               @Override
               public Void call() throws Exception {
-                rpc.deleteSession(name, options);
+                gapicRpc.deleteSession(name, options);
                 return null;
               }
             });
@@ -904,7 +904,7 @@ ByteString beginTransaction() {
                 new Callable<Transaction>() {
                   @Override
                   public Transaction call() throws Exception {
-                    return rpc.beginTransaction(request, options);
+                    return gapicRpc.beginTransaction(request, options);
                   }
                 });
         if (txn.getId().isEmpty()) {
@@ -919,11 +919,11 @@ public Transaction call() throws Exception {
     }
 
     TransactionContextImpl newTransaction() {
-      TransactionContextImpl txn = new TransactionContextImpl(this, readyTransactionId, rpc,
-          defaultPrefetchChunks);
+      TransactionContextImpl txn =
+          new TransactionContextImpl(this, readyTransactionId, gapicRpc, defaultPrefetchChunks);
       return txn;
     }
-    
+
     <T extends SessionTransaction> T setActive(@Nullable T ctx) {
       throwIfTransactionsPending();
 
@@ -1097,10 +1097,7 @@ CloseableIterator<PartialResultSet> startStream(@Nullable ByteString resumeToken
               }
               SpannerRpc.StreamingCall call =
                   rpc.executeQuery(request.build(), stream.consumer(), session.options);
-              // We get one message for free.
-              if (prefetchChunks > 1) {
-                call.request(prefetchChunks - 1);
-              }
+              call.request(prefetchChunks);
               stream.setCall(call);
               return stream;
             }
@@ -1207,10 +1204,7 @@ CloseableIterator<PartialResultSet> startStream(@Nullable ByteString resumeToken
               }
               SpannerRpc.StreamingCall call =
                   rpc.read(builder.build(), stream.consumer(), session.options);
-              // We get one message for free.
-              if (prefetchChunks > 1) {
-                call.request(prefetchChunks - 1);
-              }
+              call.request(prefetchChunks);
               stream.setCall(call);
               return stream;
             }
@@ -2452,6 +2446,49 @@ interface CloseableIterator<T> extends Iterator<T> {
     void close(@Nullable String message);
   }
 
+  private static final class CloseableServerStreamIterator<T> implements CloseableIterator<T> {
+
+    private final ServerStream<T> stream;
+    private final Iterator<T> iterator;
+
+    public CloseableServerStreamIterator(ServerStream<T> stream) {
+      this.stream = stream;
+      this.iterator = stream.iterator();
+    }
+
+    @Override
+    public boolean hasNext() {
+      try {
+        return iterator.hasNext();
+      } catch (Exception e) {
+        throw SpannerExceptionFactory.newSpannerException(e);
+      }
+    }
+
+    @Override
+    public T next() {
+      try {
+        return iterator.next();
+      } catch (Exception e) {
+        throw SpannerExceptionFactory.newSpannerException(e);
+      }
+    }
+
+    @Override
+    public void remove() {
+      throw new UnsupportedOperationException("Not supported: remove.");
+    }
+
+    @Override
+    public void close(@Nullable String message) {
+      try {
+        stream.cancel();
+      } catch (Exception e) {
+        throw SpannerExceptionFactory.newSpannerException(e);
+      }
+    }
+  }
+
   /** Adapts a streaming read/query call into an iterator over partial result sets. */
   @VisibleForTesting
   static class GrpcStreamIterator extends AbstractIterator<PartialResultSet>
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerOptions.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerOptions.java
index b5ca59c1b9c1..d0d298705deb 100644
--- a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerOptions.java
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerOptions.java
@@ -16,30 +16,23 @@
 
 package com.google.cloud.spanner;
 
-import com.google.cloud.grpc.GrpcTransportOptions;
+import com.google.api.gax.grpc.GrpcInterceptorProvider;
+import com.google.api.gax.rpc.TransportChannelProvider;
 import com.google.cloud.ServiceDefaults;
 import com.google.cloud.ServiceOptions;
 import com.google.cloud.ServiceRpc;
 import com.google.cloud.TransportOptions;
-import com.google.cloud.spanner.spi.v1.GrpcSpannerRpc;
-import com.google.cloud.spanner.spi.v1.SpannerRpc;
+import com.google.cloud.grpc.GrpcTransportOptions;
 import com.google.cloud.spanner.spi.SpannerRpcFactory;
-import com.google.common.base.MoreObjects;
+import com.google.cloud.spanner.spi.v1.GapicSpannerRpc;
+import com.google.cloud.spanner.spi.v1.SpannerRpc;
 import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
-import io.grpc.ClientInterceptor;
-import io.grpc.ManagedChannel;
-import io.grpc.netty.shaded.io.grpc.netty.GrpcSslContexts;
-import io.grpc.netty.shaded.io.grpc.netty.NettyChannelBuilder;
-import io.grpc.netty.shaded.io.netty.handler.ssl.SslContext;
 import java.net.MalformedURLException;
 import java.net.URL;
-import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import javax.net.ssl.SSLException;
 
 /** Options for the Cloud Spanner service. */
 public class SpannerOptions extends ServiceOptions<Spanner, SpannerOptions> {
@@ -52,8 +45,13 @@ public class SpannerOptions extends ServiceOptions<Spanner, SpannerOptions> {
           "https://www.googleapis.com/auth/spanner.admin",
           "https://www.googleapis.com/auth/spanner.data");
   private static final int MAX_CHANNELS = 256;
-  private static final RpcChannelFactory DEFAULT_RPC_CHANNEL_FACTORY = new NettyRpcChannelFactory();
-
+  private final TransportChannelProvider channelProvider;
+  private final GrpcInterceptorProvider interceptorProvider;
+  private final SessionPoolOptions sessionPoolOptions;
+  private final int prefetchChunks;
+  private final int numChannels;
+  private final ImmutableMap<String, String> sessionLabels;
+  
   /** Default implementation of {@code SpannerFactory}. */
   private static class DefaultSpannerFactory implements SpannerFactory {
     private static final DefaultSpannerFactory INSTANCE = new DefaultSpannerFactory();
@@ -70,29 +68,21 @@ private static class DefaultSpannerRpcFactory implements SpannerRpcFactory {
 
     @Override
     public ServiceRpc create(SpannerOptions options) {
-      return new GrpcSpannerRpc(options);
+      return new GapicSpannerRpc(options);
     }
   }
 
-  private final List<ManagedChannel> rpcChannels;
-  private final SessionPoolOptions sessionPoolOptions;
-  private final int prefetchChunks;
-  private final int numChannels;
-  private final ImmutableMap<String, String> sessionLabels;
-
   private SpannerOptions(Builder builder) {
     super(SpannerFactory.class, SpannerRpcFactory.class, builder, new SpannerDefaults());
     numChannels = builder.numChannels;
-    String userAgent = getUserAgent();
-    RpcChannelFactory defaultRpcChannelFactory =
-        userAgent == null
-            ? DEFAULT_RPC_CHANNEL_FACTORY
-            : new NettyRpcChannelFactory(userAgent);
-    rpcChannels =
-        createChannels(
-            getHost(),
-            MoreObjects.firstNonNull(builder.rpcChannelFactory, defaultRpcChannelFactory),
-            numChannels);
+    Preconditions.checkArgument(
+        numChannels >= 1 && numChannels <= MAX_CHANNELS,
+        "Number of channels must fall in the range [1, %s], found: %s",
+        MAX_CHANNELS,
+        numChannels);
+
+    channelProvider = builder.channelProvider;
+    interceptorProvider = builder.interceptorProvider;
     sessionPoolOptions =
         builder.sessionPoolOptions != null
             ? builder.sessionPoolOptions
@@ -103,10 +93,11 @@ private SpannerOptions(Builder builder) {
 
   /** Builder for {@link SpannerOptions} instances. */
   public static class Builder
-      extends ServiceOptions.Builder<
-      Spanner, SpannerOptions, SpannerOptions.Builder> {
+      extends ServiceOptions.Builder<Spanner, SpannerOptions, SpannerOptions.Builder> {
     private static final int DEFAULT_PREFETCH_CHUNKS = 4;
-    private RpcChannelFactory rpcChannelFactory;
+    private TransportChannelProvider channelProvider;
+    private GrpcInterceptorProvider interceptorProvider;
+
     /** By default, we create 4 channels per {@link SpannerOptions} */
     private int numChannels = 4;
 
@@ -122,6 +113,8 @@ private Builder() {}
       this.sessionPoolOptions = options.sessionPoolOptions;
       this.prefetchChunks = options.prefetchChunks;
       this.sessionLabels = options.sessionLabels;
+      this.channelProvider = options.channelProvider;
+      this.interceptorProvider = options.interceptorProvider;
     }
 
     @Override
@@ -133,9 +126,21 @@ public Builder setTransportOptions(TransportOptions transportOptions) {
       return super.setTransportOptions(transportOptions);
     }
 
-    /** Sets the factory for creating gRPC channels. If not set, a default will be used. */
-    public Builder setRpcChannelFactory(RpcChannelFactory factory) {
-      this.rpcChannelFactory = factory;
+    /**
+     * Sets the {@code ChannelProvider}. {@link GapicSpannerRpc} would create a default one if none
+     * is provided.
+     */
+    public Builder setChannelProvider(TransportChannelProvider channelProvider) {
+      this.channelProvider = channelProvider;
+      return this;
+    }
+
+    /**
+     * Sets the {@code GrpcInterceptorProvider}. {@link GapicSpannerRpc} would create a default one
+     * if none is provided.
+     */
+    public Builder setInterceptorProvider(GrpcInterceptorProvider interceptorProvider) {
+      this.interceptorProvider = interceptorProvider;
       return this;
     }
 
@@ -196,14 +201,6 @@ public SpannerOptions build() {
     }
   }
 
-  /**
-   * Interface for gRPC channel creation. Most users won't need to use this, as the default covers
-   * typical deployment scenarios.
-   */
-  public interface RpcChannelFactory {
-    ManagedChannel newChannel(String host, int port);
-  }
-
   /** Returns default instance of {@code SpannerOptions}. */
   public static SpannerOptions getDefaultInstance() {
     return newBuilder().build();
@@ -213,8 +210,16 @@ public static Builder newBuilder() {
     return new Builder();
   }
 
-  public List<ManagedChannel> getRpcChannels() {
-    return rpcChannels;
+  public TransportChannelProvider getChannelProvider() {
+    return channelProvider;
+  }
+
+  public GrpcInterceptorProvider getInterceptorProvider() {
+    return interceptorProvider;
+  }
+
+  public int getNumChannels() {
+    return numChannels;
   }
 
   public SessionPoolOptions getSessionPoolOptions() {
@@ -233,90 +238,12 @@ public static GrpcTransportOptions getDefaultGrpcTransportOptions() {
     return GrpcTransportOptions.newBuilder().build();
   }
 
-  /**
-   * Returns the default RPC channel factory used when none is specified. This may be useful for
-   * callers that wish to add interceptors to gRPC channels used by the Cloud Spanner client
-   * library.
-   */
-  public static RpcChannelFactory getDefaultRpcChannelFactory() {
-    return DEFAULT_RPC_CHANNEL_FACTORY;
-  }
-
   @Override
   protected String getDefaultHost() {
     return DEFAULT_HOST;
   }
 
-  private static List<ManagedChannel> createChannels(
-      String rootUrl, RpcChannelFactory factory, int numChannels) {
-    Preconditions.checkArgument(
-        numChannels >= 1 && numChannels <= MAX_CHANNELS,
-        "Number of channels must fall in the range [1, %s], found: %s",
-        MAX_CHANNELS,
-        numChannels);
-    ImmutableList.Builder<ManagedChannel> builder = ImmutableList.builder();
-    for (int i = 0; i < numChannels; i++) {
-      builder.add(createChannel(rootUrl, factory));
-    }
-    return builder.build();
-  }
-
-  private static ManagedChannel createChannel(String rootUrl, RpcChannelFactory factory) {
-    URL url;
-    try {
-      url = new URL(rootUrl);
-    } catch (MalformedURLException e) {
-      throw new IllegalArgumentException("Invalid host: " + rootUrl, e);
-    }
-    ManagedChannel channel =
-        factory.newChannel(url.getHost(), url.getPort() > 0 ? url.getPort() : url.getDefaultPort());
-    return channel;
-  }
-
-  static class NettyRpcChannelFactory implements RpcChannelFactory {
-    private static final int MAX_MESSAGE_SIZE = 100 * 1024 * 1024;
-    private static final int MAX_HEADER_LIST_SIZE = 32 * 1024; //bytes
-    private final String userAgent;
-    private final List<ClientInterceptor> interceptors;
-
-    NettyRpcChannelFactory() {
-      this(null);
-    }
-
-    NettyRpcChannelFactory(String userAgent) {
-      this(userAgent, ImmutableList.<ClientInterceptor>of());
-    }
-
-    NettyRpcChannelFactory(String userAgent, List<ClientInterceptor> interceptors) {
-      this.userAgent = userAgent;
-      this.interceptors = interceptors;
-    }
-
-    @Override
-    public ManagedChannel newChannel(String host, int port) {
-      NettyChannelBuilder builder =
-          NettyChannelBuilder.forAddress(host, port)
-            .sslContext(newSslContext())
-            .intercept(interceptors)
-            .maxHeaderListSize(MAX_HEADER_LIST_SIZE)
-            .maxMessageSize(MAX_MESSAGE_SIZE);
-      if (userAgent != null) {
-        builder.userAgent(userAgent);
-      }
-      return builder.build();
-    }
-
-    private static SslContext newSslContext() {
-      try {
-        return GrpcSslContexts.forClient().ciphers(null).build();
-      } catch (SSLException e) {
-        throw new RuntimeException("SSL configuration failed: " + e.getMessage(), e);
-      }
-    }
-  }
-
-  private static class SpannerDefaults implements
-      ServiceDefaults<Spanner, SpannerOptions> {
+  private static class SpannerDefaults implements ServiceDefaults<Spanner, SpannerOptions> {
 
     @Override
     public SpannerFactory getDefaultServiceFactory() {
@@ -348,4 +275,15 @@ protected SpannerRpc getSpannerRpcV1() {
   public Builder toBuilder() {
     return new Builder(this);
   }
+
+  public String getEndpoint() {
+    URL url;
+    try {
+      url = new URL(getHost());
+    } catch (MalformedURLException e) {
+      throw new IllegalArgumentException("Invalid host: " + getHost(), e);
+    }
+    return String.format(
+        "%s:%s", url.getHost(), url.getPort() < 0 ? url.getDefaultPort() : url.getPort());
+  }
 }
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GapicSpannerRpc.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GapicSpannerRpc.java
new file mode 100644
index 000000000000..4f367772cdcc
--- /dev/null
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GapicSpannerRpc.java
@@ -0,0 +1,585 @@
+/*
+ * Copyright 2018 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.cloud.spanner.spi.v1;
+
+import static com.google.cloud.spanner.SpannerExceptionFactory.newSpannerException;
+
+import com.google.api.core.ApiFunction;
+import com.google.api.gax.core.CredentialsProvider;
+import com.google.api.gax.core.GaxProperties;
+import com.google.api.gax.core.InstantiatingExecutorProvider;
+import com.google.api.gax.grpc.GaxGrpcProperties;
+import com.google.api.gax.grpc.GrpcCallContext;
+import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
+import com.google.api.gax.longrunning.OperationFuture;
+import com.google.api.gax.rpc.AlreadyExistsException;
+import com.google.api.gax.rpc.ApiClientHeaderProvider;
+import com.google.api.gax.rpc.HeaderProvider;
+import com.google.api.gax.rpc.OperationCallable;
+import com.google.api.gax.rpc.ResponseObserver;
+import com.google.api.gax.rpc.StatusCode;
+import com.google.api.gax.rpc.StreamController;
+import com.google.api.gax.rpc.TransportChannelProvider;
+import com.google.api.gax.rpc.UnaryCallSettings;
+import com.google.api.pathtemplate.PathTemplate;
+import com.google.cloud.ServiceOptions;
+import com.google.cloud.grpc.GrpcTransportOptions;
+import com.google.cloud.spanner.SpannerException;
+import com.google.cloud.spanner.SpannerExceptionFactory;
+import com.google.cloud.spanner.SpannerOptions;
+import com.google.cloud.spanner.admin.database.v1.stub.DatabaseAdminStub;
+import com.google.cloud.spanner.admin.database.v1.stub.DatabaseAdminStubSettings;
+import com.google.cloud.spanner.admin.database.v1.stub.GrpcDatabaseAdminStub;
+import com.google.cloud.spanner.admin.instance.v1.stub.GrpcInstanceAdminStub;
+import com.google.cloud.spanner.admin.instance.v1.stub.InstanceAdminStub;
+import com.google.cloud.spanner.admin.instance.v1.stub.InstanceAdminStubSettings;
+import com.google.cloud.spanner.spi.v1.SpannerRpc.Option;
+import com.google.cloud.spanner.v1.stub.GrpcSpannerStub;
+import com.google.cloud.spanner.v1.stub.SpannerStub;
+import com.google.cloud.spanner.v1.stub.SpannerStubSettings;
+import com.google.common.base.MoreObjects;
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableSet;
+import com.google.longrunning.GetOperationRequest;
+import com.google.longrunning.Operation;
+import com.google.protobuf.Empty;
+import com.google.protobuf.FieldMask;
+import com.google.spanner.admin.database.v1.CreateDatabaseMetadata;
+import com.google.spanner.admin.database.v1.CreateDatabaseRequest;
+import com.google.spanner.admin.database.v1.Database;
+import com.google.spanner.admin.database.v1.DropDatabaseRequest;
+import com.google.spanner.admin.database.v1.GetDatabaseDdlRequest;
+import com.google.spanner.admin.database.v1.GetDatabaseRequest;
+import com.google.spanner.admin.database.v1.ListDatabasesRequest;
+import com.google.spanner.admin.database.v1.ListDatabasesResponse;
+import com.google.spanner.admin.database.v1.UpdateDatabaseDdlMetadata;
+import com.google.spanner.admin.database.v1.UpdateDatabaseDdlRequest;
+import com.google.spanner.admin.instance.v1.CreateInstanceMetadata;
+import com.google.spanner.admin.instance.v1.CreateInstanceRequest;
+import com.google.spanner.admin.instance.v1.DeleteInstanceRequest;
+import com.google.spanner.admin.instance.v1.GetInstanceConfigRequest;
+import com.google.spanner.admin.instance.v1.GetInstanceRequest;
+import com.google.spanner.admin.instance.v1.Instance;
+import com.google.spanner.admin.instance.v1.InstanceConfig;
+import com.google.spanner.admin.instance.v1.ListInstanceConfigsRequest;
+import com.google.spanner.admin.instance.v1.ListInstanceConfigsResponse;
+import com.google.spanner.admin.instance.v1.ListInstancesRequest;
+import com.google.spanner.admin.instance.v1.ListInstancesResponse;
+import com.google.spanner.admin.instance.v1.UpdateInstanceMetadata;
+import com.google.spanner.admin.instance.v1.UpdateInstanceRequest;
+import com.google.spanner.v1.BeginTransactionRequest;
+import com.google.spanner.v1.CommitRequest;
+import com.google.spanner.v1.CommitResponse;
+import com.google.spanner.v1.CreateSessionRequest;
+import com.google.spanner.v1.DeleteSessionRequest;
+import com.google.spanner.v1.ExecuteSqlRequest;
+import com.google.spanner.v1.PartialResultSet;
+import com.google.spanner.v1.PartitionQueryRequest;
+import com.google.spanner.v1.PartitionReadRequest;
+import com.google.spanner.v1.PartitionResponse;
+import com.google.spanner.v1.ReadRequest;
+import com.google.spanner.v1.ResultSet;
+import com.google.spanner.v1.RollbackRequest;
+import com.google.spanner.v1.Session;
+import com.google.spanner.v1.Transaction;
+import io.grpc.Context;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.CancellationException;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+import javax.annotation.Nullable;
+
+/** Implementation of Cloud Spanner remote calls using Gapic libraries. */
+public class GapicSpannerRpc implements SpannerRpc {
+
+  private static final PathTemplate PROJECT_NAME_TEMPLATE =
+      PathTemplate.create("projects/{project}");
+  private static final PathTemplate OPERATION_NAME_TEMPLATE =
+      PathTemplate.create("{database=projects/*/instances/*/databases/*}/operations/{operation}");
+  private static final int MAX_MESSAGE_SIZE = 100 * 1024 * 1024;
+  private static final int MAX_METADATA_SIZE = 32 * 1024; // bytes
+
+  private final SpannerStub spannerStub;
+  private final InstanceAdminStub instanceAdminStub;
+  private final DatabaseAdminStub databaseAdminStub;
+  private final String projectId;
+  private final String projectName;
+  private final SpannerMetadataProvider metadataProvider;
+
+  public static GapicSpannerRpc create(SpannerOptions options) {
+    return new GapicSpannerRpc(options);
+  }
+
+  public GapicSpannerRpc(SpannerOptions options) {
+    this.projectId = options.getProjectId();
+    this.projectName = PROJECT_NAME_TEMPLATE.instantiate("project", this.projectId);
+
+    // create a metadataProvider which combines both internal headers and
+    // per-method-call extra headers for channelProvider to inject the headers
+    // for rpc calls
+    ApiClientHeaderProvider.Builder internalHeaderProviderBuilder =
+        ApiClientHeaderProvider.newBuilder();
+    ApiClientHeaderProvider internalHeaderProvider =
+        internalHeaderProviderBuilder
+            .setClientLibToken(
+                ServiceOptions.getGoogApiClientLibName(),
+                GaxProperties.getLibraryVersion(options.getClass()))
+            .setTransportToken(
+                GaxGrpcProperties.getGrpcTokenName(), GaxGrpcProperties.getGrpcVersion())
+            .build();
+
+    HeaderProvider mergedHeaderProvider = options.getMergedHeaderProvider(internalHeaderProvider);
+    this.metadataProvider =
+        SpannerMetadataProvider.create(
+            mergedHeaderProvider.getHeaders(),
+            internalHeaderProviderBuilder.getResourceHeaderKey());
+
+    // First check if SpannerOptions provides a TransportChannerProvider. Create one
+    // with information gathered from SpannerOptions if none is provided
+    TransportChannelProvider channelProvider =
+        MoreObjects.firstNonNull(
+            options.getChannelProvider(),
+            InstantiatingGrpcChannelProvider.newBuilder()
+                .setEndpoint(options.getEndpoint())
+                .setMaxInboundMessageSize(MAX_MESSAGE_SIZE)
+                .setMaxInboundMetadataSize(MAX_METADATA_SIZE)
+                .setPoolSize(options.getNumChannels())
+
+                // Then check if SpannerOptions provides an InterceptorProvider. Create a default
+                // SpannerInterceptorProvider if none is provided
+                .setInterceptorProvider(
+                    MoreObjects.firstNonNull(
+                        options.getInterceptorProvider(),
+                        SpannerInterceptorProvider.createDefault()))
+                .setHeaderProvider(mergedHeaderProvider)
+                .setExecutorProvider(InstantiatingExecutorProvider.newBuilder().build())
+                .build());
+
+    CredentialsProvider credentialsProvider =
+        GrpcTransportOptions.setUpCredentialsProvider(options);
+
+    // Disabling retry for now because spanner handles retry in SpannerImpl.
+    // We will finally want to improve gax but for smooth transitioning we
+    // preserve the retry in SpannerImpl
+    try {
+      // TODO: bump the version of gax and remove this try-catch block
+      // applyToAllUnaryMethods does not throw exception in the latest version
+      this.spannerStub =
+          GrpcSpannerStub.create(
+              SpannerStubSettings.newBuilder()
+                  .setTransportChannelProvider(channelProvider)
+                  .setCredentialsProvider(credentialsProvider)
+                  .applyToAllUnaryMethods(
+                      new ApiFunction<UnaryCallSettings.Builder<?, ?>, Void>() {
+                        @Override
+                        public Void apply(UnaryCallSettings.Builder<?, ?> builder) {
+                          builder.setRetryableCodes(ImmutableSet.<StatusCode.Code>of());
+                          return null;
+                        }
+                      })
+                  .build());
+
+      this.instanceAdminStub =
+          GrpcInstanceAdminStub.create(
+              InstanceAdminStubSettings.newBuilder()
+                  .setTransportChannelProvider(channelProvider)
+                  .setCredentialsProvider(credentialsProvider)
+                  .applyToAllUnaryMethods(
+                      new ApiFunction<UnaryCallSettings.Builder<?, ?>, Void>() {
+                        @Override
+                        public Void apply(UnaryCallSettings.Builder<?, ?> builder) {
+                          builder.setRetryableCodes(ImmutableSet.<StatusCode.Code>of());
+                          return null;
+                        }
+                      })
+                  .build());
+      this.databaseAdminStub =
+          GrpcDatabaseAdminStub.create(
+              DatabaseAdminStubSettings.newBuilder()
+                  .setTransportChannelProvider(channelProvider)
+                  .setCredentialsProvider(credentialsProvider)
+                  .applyToAllUnaryMethods(
+                      new ApiFunction<UnaryCallSettings.Builder<?, ?>, Void>() {
+                        @Override
+                        public Void apply(UnaryCallSettings.Builder<?, ?> builder) {
+                          builder.setRetryableCodes(ImmutableSet.<StatusCode.Code>of());
+                          return null;
+                        }
+                      })
+                  .build());
+    } catch (Exception e) {
+      throw newSpannerException(e);
+    }
+  }
+
+  @Override
+  public Paginated<InstanceConfig> listInstanceConfigs(int pageSize, @Nullable String pageToken)
+      throws SpannerException {
+    ListInstanceConfigsRequest.Builder requestBuilder =
+        ListInstanceConfigsRequest.newBuilder().setParent(projectName).setPageSize(pageSize);
+    if (pageToken != null) {
+      requestBuilder.setPageToken(pageToken);
+    }
+    ListInstanceConfigsRequest request = requestBuilder.build();
+
+    GrpcCallContext context = newCallContext(null, projectName);
+    ListInstanceConfigsResponse response =
+        get(instanceAdminStub.listInstanceConfigsCallable().futureCall(request, context));
+    return new Paginated<>(response.getInstanceConfigsList(), response.getNextPageToken());
+  }
+
+  @Override
+  public InstanceConfig getInstanceConfig(String instanceConfigName) throws SpannerException {
+    GetInstanceConfigRequest request =
+        GetInstanceConfigRequest.newBuilder().setName(instanceConfigName).build();
+
+    GrpcCallContext context = newCallContext(null, projectName);
+    return get(instanceAdminStub.getInstanceConfigCallable().futureCall(request, context));
+  }
+
+  @Override
+  public Paginated<Instance> listInstances(
+      int pageSize, @Nullable String pageToken, @Nullable String filter) throws SpannerException {
+    ListInstancesRequest.Builder requestBuilder =
+        ListInstancesRequest.newBuilder().setParent(projectName).setPageSize(pageSize);
+    if (pageToken != null) {
+      requestBuilder.setPageToken(pageToken);
+    }
+    if (filter != null) {
+      requestBuilder.setFilter(filter);
+    }
+    ListInstancesRequest request = requestBuilder.build();
+
+    GrpcCallContext context = newCallContext(null, projectName);
+    ListInstancesResponse response =
+        get(instanceAdminStub.listInstancesCallable().futureCall(request, context));
+    return new Paginated<>(response.getInstancesList(), response.getNextPageToken());
+  }
+
+  @Override
+  public OperationFuture<Instance, CreateInstanceMetadata> createInstance(
+      String parent, String instanceId, Instance instance) throws SpannerException {
+    CreateInstanceRequest request =
+        CreateInstanceRequest.newBuilder()
+            .setParent(parent)
+            .setInstanceId(instanceId)
+            .setInstance(instance)
+            .build();
+    GrpcCallContext context = newCallContext(null, parent);
+    return instanceAdminStub.createInstanceOperationCallable().futureCall(request, context);
+  }
+
+  @Override
+  public OperationFuture<Instance, UpdateInstanceMetadata> updateInstance(
+      Instance instance, FieldMask fieldMask) throws SpannerException {
+    UpdateInstanceRequest request =
+        UpdateInstanceRequest.newBuilder().setInstance(instance).setFieldMask(fieldMask).build();
+    GrpcCallContext context = newCallContext(null, instance.getName());
+    return instanceAdminStub.updateInstanceOperationCallable().futureCall(request, context);
+  }
+
+  @Override
+  public Instance getInstance(String instanceName) throws SpannerException {
+    GetInstanceRequest request = GetInstanceRequest.newBuilder().setName(instanceName).build();
+
+    GrpcCallContext context = newCallContext(null, instanceName);
+    return get(instanceAdminStub.getInstanceCallable().futureCall(request, context));
+  }
+
+  @Override
+  public void deleteInstance(String instanceName) throws SpannerException {
+    DeleteInstanceRequest request =
+        DeleteInstanceRequest.newBuilder().setName(instanceName).build();
+
+    GrpcCallContext context = newCallContext(null, instanceName);
+    get(instanceAdminStub.deleteInstanceCallable().futureCall(request, context));
+  }
+
+  @Override
+  public Paginated<Database> listDatabases(
+      String instanceName, int pageSize, @Nullable String pageToken) throws SpannerException {
+    ListDatabasesRequest.Builder requestBuilder =
+        ListDatabasesRequest.newBuilder().setParent(instanceName).setPageSize(pageSize);
+    if (pageToken != null) {
+      requestBuilder.setPageToken(pageToken);
+    }
+    ListDatabasesRequest request = requestBuilder.build();
+
+    GrpcCallContext context = newCallContext(null, instanceName);
+    ListDatabasesResponse response =
+        get(databaseAdminStub.listDatabasesCallable().futureCall(request, context));
+    return new Paginated<>(response.getDatabasesList(), response.getNextPageToken());
+  }
+
+  @Override
+  public OperationFuture<Database, CreateDatabaseMetadata> createDatabase(
+      String instanceName, String createDatabaseStatement, Iterable<String> additionalStatements)
+      throws SpannerException {
+    CreateDatabaseRequest request =
+        CreateDatabaseRequest.newBuilder()
+            .setParent(instanceName)
+            .setCreateStatement(createDatabaseStatement)
+            .addAllExtraStatements(additionalStatements)
+            .build();
+    GrpcCallContext context = newCallContext(null, instanceName);
+    return databaseAdminStub.createDatabaseOperationCallable().futureCall(request, context);
+  }
+
+  @Override
+  public OperationFuture<Empty, UpdateDatabaseDdlMetadata> updateDatabaseDdl(
+      String databaseName, Iterable<String> updateDatabaseStatements, @Nullable String updateId)
+      throws SpannerException {
+    UpdateDatabaseDdlRequest request =
+        UpdateDatabaseDdlRequest.newBuilder()
+            .setDatabase(databaseName)
+            .addAllStatements(updateDatabaseStatements)
+            .setOperationId(MoreObjects.firstNonNull(updateId, ""))
+            .build();
+    GrpcCallContext context = newCallContext(null, databaseName);
+    OperationCallable<UpdateDatabaseDdlRequest, Empty, UpdateDatabaseDdlMetadata> callable =
+        databaseAdminStub.updateDatabaseDdlOperationCallable();
+    OperationFuture<Empty, UpdateDatabaseDdlMetadata> operationFuture =
+        callable.futureCall(request, context);
+    try {
+      operationFuture.getInitialFuture().get();
+    } catch (InterruptedException e) {
+      throw newSpannerException(e);
+    } catch (ExecutionException e) {
+      Throwable t = e.getCause();
+      if (t instanceof AlreadyExistsException) {
+        String operationName =
+            OPERATION_NAME_TEMPLATE.instantiate("database", databaseName, "operation", updateId);
+        return callable.resumeFutureCall(operationName, context);
+      }
+    }
+    return operationFuture;
+  }
+
+  @Override
+  public void dropDatabase(String databaseName) throws SpannerException {
+    DropDatabaseRequest request =
+        DropDatabaseRequest.newBuilder().setDatabase(databaseName).build();
+
+    GrpcCallContext context = newCallContext(null, databaseName);
+    get(databaseAdminStub.dropDatabaseCallable().futureCall(request, context));
+  }
+
+  @Override
+  public Database getDatabase(String databaseName) throws SpannerException {
+    GetDatabaseRequest request = GetDatabaseRequest.newBuilder().setName(databaseName).build();
+
+    GrpcCallContext context = newCallContext(null, databaseName);
+    return get(databaseAdminStub.getDatabaseCallable().futureCall(request, context));
+  }
+
+  @Override
+  public List<String> getDatabaseDdl(String databaseName) throws SpannerException {
+    GetDatabaseDdlRequest request =
+        GetDatabaseDdlRequest.newBuilder().setDatabase(databaseName).build();
+
+    GrpcCallContext context = newCallContext(null, databaseName);
+    return get(databaseAdminStub.getDatabaseDdlCallable().futureCall(request, context))
+        .getStatementsList();
+  }
+
+  @Override
+  public Operation getOperation(String name) throws SpannerException {
+    GetOperationRequest request = GetOperationRequest.newBuilder().setName(name).build();
+    GrpcCallContext context = newCallContext(null, name);
+    return get(
+        databaseAdminStub.getOperationsStub().getOperationCallable().futureCall(request, context));
+  }
+
+  @Override
+  public Session createSession(
+      String databaseName, @Nullable Map<String, String> labels, @Nullable Map<Option, ?> options)
+      throws SpannerException {
+    CreateSessionRequest.Builder requestBuilder =
+        CreateSessionRequest.newBuilder().setDatabase(databaseName);
+    if (labels != null && !labels.isEmpty()) {
+      Session.Builder session = Session.newBuilder().putAllLabels(labels);
+      requestBuilder.setSession(session);
+    }
+    CreateSessionRequest request = requestBuilder.build();
+    GrpcCallContext context = newCallContext(options, databaseName);
+    return get(spannerStub.createSessionCallable().futureCall(request, context));
+  }
+
+  @Override
+  public void deleteSession(String sessionName, @Nullable Map<Option, ?> options)
+      throws SpannerException {
+    DeleteSessionRequest request = DeleteSessionRequest.newBuilder().setName(sessionName).build();
+    GrpcCallContext context = newCallContext(options, sessionName);
+    get(spannerStub.deleteSessionCallable().futureCall(request, context));
+  }
+
+  @Override
+  public StreamingCall read(
+      ReadRequest request, ResultStreamConsumer consumer, @Nullable Map<Option, ?> options) {
+    GrpcCallContext context = newCallContext(options, request.getSession());
+    SpannerResponseObserver responseObserver = new SpannerResponseObserver(consumer);
+    spannerStub.streamingReadCallable().call(request, responseObserver, context);
+    final StreamController controller = responseObserver.getController();
+    return new StreamingCall() {
+      @Override
+      public void request(int numMessage) {
+        controller.request(numMessage);
+      }
+
+      // TODO(hzyi): streamController currently does not support cancel with message. Add
+      // this in gax and update this method later
+      @Override
+      public void cancel(String message) {
+        controller.cancel();
+      }
+    };
+  }
+
+  @Override
+  public ResultSet executeQuery(ExecuteSqlRequest request, @Nullable Map<Option, ?> options) {
+    GrpcCallContext context = newCallContext(options, request.getSession());
+    return get(spannerStub.executeSqlCallable().futureCall(request, context));
+  }
+
+  @Override
+  public StreamingCall executeQuery(
+      ExecuteSqlRequest request, ResultStreamConsumer consumer, @Nullable Map<Option, ?> options) {
+    GrpcCallContext context = newCallContext(options, request.getSession());
+    SpannerResponseObserver responseObserver = new SpannerResponseObserver(consumer);
+    spannerStub.executeStreamingSqlCallable().call(request, responseObserver, context);
+    final StreamController controller = responseObserver.getController();
+    return new StreamingCall() {
+      @Override
+      public void request(int numMessage) {
+        controller.request(numMessage);
+      }
+
+      // TODO(hzyi): streamController currently does not support cancel with message. Add
+      // this in gax and update this method later
+      @Override
+      public void cancel(String message) {
+        controller.cancel();
+      }
+    };
+  }
+
+  @Override
+  public Transaction beginTransaction(
+      BeginTransactionRequest request, @Nullable Map<Option, ?> options) throws SpannerException {
+    GrpcCallContext context = newCallContext(options, request.getSession());
+    return get(spannerStub.beginTransactionCallable().futureCall(request, context));
+  }
+
+  @Override
+  public CommitResponse commit(CommitRequest commitRequest, @Nullable Map<Option, ?> options)
+      throws SpannerException {
+    GrpcCallContext context = newCallContext(options, commitRequest.getSession());
+    return get(spannerStub.commitCallable().futureCall(commitRequest, context));
+  }
+
+  @Override
+  public void rollback(RollbackRequest request, @Nullable Map<Option, ?> options)
+      throws SpannerException {
+    GrpcCallContext context = newCallContext(options, request.getSession());
+    get(spannerStub.rollbackCallable().futureCall(request, context));
+  }
+
+  @Override
+  public PartitionResponse partitionQuery(
+      PartitionQueryRequest request, @Nullable Map<Option, ?> options) throws SpannerException {
+    GrpcCallContext context = newCallContext(options, request.getSession());
+    return get(spannerStub.partitionQueryCallable().futureCall(request, context));
+  }
+
+  @Override
+  public PartitionResponse partitionRead(
+      PartitionReadRequest request, @Nullable Map<Option, ?> options) throws SpannerException {
+    GrpcCallContext context = newCallContext(options, request.getSession());
+    return get(spannerStub.partitionReadCallable().futureCall(request, context));
+  }
+
+  /** Gets the result of an async RPC call, handling any exceptions encountered. */
+  private static <T> T get(final Future<T> future) throws SpannerException {
+    final Context context = Context.current();
+    try {
+      return future.get();
+    } catch (InterruptedException e) {
+      // We are the sole consumer of the future, so cancel it.
+      future.cancel(true);
+      throw SpannerExceptionFactory.propagateInterrupt(e);
+    } catch (ExecutionException | CancellationException e) {
+      throw newSpannerException(context, e);
+    }
+  }
+
+  private GrpcCallContext newCallContext(@Nullable Map<Option, ?> options, String resource) {
+    GrpcCallContext context = GrpcCallContext.createDefault();
+    if (options != null) {
+      context = context.withChannelAffinity(Option.CHANNEL_HINT.getLong(options).intValue());
+    }
+    context = context.withExtraHeaders(metadataProvider.newExtraHeaders(resource, projectName));
+    return context;
+  }
+
+  public void shutdown() {
+    this.spannerStub.close();
+    this.instanceAdminStub.close();
+    this.databaseAdminStub.close();
+  }
+
+  /**
+   * A {@code ResponseObserver} that exposes the {@code StreamController} and delegates callbacks to
+   * the {@link ResultStreamConsumer}.
+   */
+  private static class SpannerResponseObserver implements ResponseObserver<PartialResultSet> {
+    private StreamController controller;
+    private final ResultStreamConsumer consumer;
+
+    public SpannerResponseObserver(ResultStreamConsumer consumer) {
+      this.consumer = consumer;
+    }
+
+    @Override
+    public void onStart(StreamController controller) {
+
+      // Disable the auto flow control to allow client library
+      // set the number of messages it prefers to request
+      controller.disableAutoInboundFlowControl();
+      this.controller = controller;
+    }
+
+    @Override
+    public void onResponse(PartialResultSet response) {
+      consumer.onPartialResultSet(response);
+    }
+
+    @Override
+    public void onError(Throwable t) {
+      consumer.onError(newSpannerException(t));
+    }
+
+    @Override
+    public void onComplete() {
+      consumer.onCompleted();
+    }
+
+    StreamController getController() {
+      return Preconditions.checkNotNull(this.controller);
+    }
+  }
+}
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GrpcSpannerRpc.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GrpcSpannerRpc.java
deleted file mode 100644
index 0cbdf614d45e..000000000000
--- a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GrpcSpannerRpc.java
+++ /dev/null
@@ -1,684 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *       http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.google.cloud.spanner.spi.v1;
-
-import static com.google.cloud.spanner.SpannerExceptionFactory.newSpannerException;
-
-import com.google.api.gax.core.GaxProperties;
-import com.google.api.gax.grpc.GaxGrpcProperties;
-import com.google.api.gax.rpc.ApiClientHeaderProvider;
-import com.google.api.gax.rpc.HeaderProvider;
-import com.google.api.pathtemplate.PathTemplate;
-import com.google.cloud.NoCredentials;
-import com.google.cloud.ServiceOptions;
-import com.google.cloud.spanner.SpannerException;
-import com.google.cloud.spanner.SpannerExceptionFactory;
-import com.google.cloud.spanner.SpannerOptions;
-import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.MoreObjects;
-import com.google.common.collect.ImmutableList;
-import com.google.longrunning.GetOperationRequest;
-import com.google.longrunning.Operation;
-import com.google.longrunning.OperationsGrpc;
-import com.google.protobuf.FieldMask;
-import com.google.spanner.admin.database.v1.CreateDatabaseRequest;
-import com.google.spanner.admin.database.v1.Database;
-import com.google.spanner.admin.database.v1.DatabaseAdminGrpc;
-import com.google.spanner.admin.database.v1.DropDatabaseRequest;
-import com.google.spanner.admin.database.v1.GetDatabaseDdlRequest;
-import com.google.spanner.admin.database.v1.GetDatabaseRequest;
-import com.google.spanner.admin.database.v1.ListDatabasesRequest;
-import com.google.spanner.admin.database.v1.UpdateDatabaseDdlRequest;
-import com.google.spanner.admin.instance.v1.CreateInstanceRequest;
-import com.google.spanner.admin.instance.v1.DeleteInstanceRequest;
-import com.google.spanner.admin.instance.v1.GetInstanceConfigRequest;
-import com.google.spanner.admin.instance.v1.GetInstanceRequest;
-import com.google.spanner.admin.instance.v1.Instance;
-import com.google.spanner.admin.instance.v1.InstanceAdminGrpc;
-import com.google.spanner.admin.instance.v1.InstanceConfig;
-import com.google.spanner.admin.instance.v1.ListInstanceConfigsRequest;
-import com.google.spanner.admin.instance.v1.ListInstanceConfigsResponse;
-import com.google.spanner.admin.instance.v1.ListInstancesRequest;
-import com.google.spanner.admin.instance.v1.ListInstancesResponse;
-import com.google.spanner.admin.instance.v1.UpdateInstanceRequest;
-import com.google.spanner.v1.BeginTransactionRequest;
-import com.google.spanner.v1.CommitRequest;
-import com.google.spanner.v1.CommitResponse;
-import com.google.spanner.v1.CreateSessionRequest;
-import com.google.spanner.v1.DeleteSessionRequest;
-import com.google.spanner.v1.ExecuteSqlRequest;
-import com.google.spanner.v1.PartialResultSet;
-import com.google.spanner.v1.PartitionQueryRequest;
-import com.google.spanner.v1.PartitionReadRequest;
-import com.google.spanner.v1.PartitionResponse;
-import com.google.spanner.v1.ReadRequest;
-import com.google.spanner.v1.ResultSet;
-import com.google.spanner.v1.RollbackRequest;
-import com.google.spanner.v1.Session;
-import com.google.spanner.v1.SpannerGrpc;
-import com.google.spanner.v1.Transaction;
-import io.grpc.CallCredentials;
-import io.grpc.CallOptions;
-import io.grpc.Channel;
-import io.grpc.ClientCall;
-import io.grpc.ClientInterceptor;
-import io.grpc.ClientInterceptors;
-import io.grpc.Context;
-import io.grpc.ForwardingClientCall;
-import io.grpc.ForwardingClientCallListener;
-import io.grpc.Metadata;
-import io.grpc.MethodDescriptor;
-import io.grpc.ServiceDescriptor;
-import io.grpc.Status;
-import io.grpc.auth.MoreCallCredentials;
-import io.grpc.stub.AbstractStub;
-import io.grpc.stub.ClientCallStreamObserver;
-import io.grpc.stub.ClientCalls;
-import io.grpc.stub.ClientResponseObserver;
-import io.opencensus.trace.export.SampledSpanStore;
-import io.opencensus.trace.Tracing;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-import java.util.Random;
-import java.util.concurrent.CancellationException;
-import java.util.concurrent.ExecutionException;
-import java.util.concurrent.Future;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-import javax.annotation.Nullable;
-
-/** Implementation of Cloud Spanner remote calls using gRPC. */
-public class GrpcSpannerRpc implements SpannerRpc {
-  
-  static {
-    setupTracingConfig();
-  }
-  
-  private static final Logger logger = Logger.getLogger(GrpcSpannerRpc.class.getName());
-
-  private static final PathTemplate PROJECT_NAME_TEMPLATE =
-      PathTemplate.create("projects/{project}");
-
-  private final Random random = new Random();
-  private final List<Channel> channels;
-  private final String projectId;
-  private final String projectName;
-  private final CallCredentials credentials;
-  private final SpannerMetadataProvider metadataProvider;
-
-  public GrpcSpannerRpc(SpannerOptions options) {
-    this.projectId = options.getProjectId();
-    this.projectName = PROJECT_NAME_TEMPLATE.instantiate("project", this.projectId);
-    this.credentials = callCredentials(options);
-    ImmutableList.Builder<Channel> channelsBuilder = ImmutableList.builder();
-    ImmutableList.Builder<SpannerGrpc.SpannerFutureStub> stubsBuilder = ImmutableList.builder();
-    for (Channel channel : options.getRpcChannels()) {
-      channel =
-          ClientInterceptors.intercept(
-              channel,
-              new LoggingInterceptor(Level.FINER),
-              WatchdogInterceptor.newDefaultWatchdogInterceptor(),
-              new SpannerErrorInterceptor());
-      channelsBuilder.add(channel);
-      stubsBuilder.add(withCredentials(SpannerGrpc.newFutureStub(channel), credentials));
-    }
-    this.channels = channelsBuilder.build();
-
-    ApiClientHeaderProvider.Builder internalHeaderProviderBuilder =
-        ApiClientHeaderProvider.newBuilder();
-    ApiClientHeaderProvider internalHeaderProvider =
-        internalHeaderProviderBuilder
-            .setClientLibToken(
-                ServiceOptions.getGoogApiClientLibName(),
-                GaxProperties.getLibraryVersion(options.getClass()))
-            .setTransportToken(
-                GaxGrpcProperties.getGrpcTokenName(), GaxGrpcProperties.getGrpcVersion())
-            .build();
-
-    HeaderProvider mergedHeaderProvider = options.getMergedHeaderProvider(internalHeaderProvider);
-    this.metadataProvider =
-        SpannerMetadataProvider.create(
-            mergedHeaderProvider.getHeaders(),
-            internalHeaderProviderBuilder.getResourceHeaderKey());
-  }
-
-  private static CallCredentials callCredentials(SpannerOptions options) {
-    if (options.getCredentials() == null) {
-      return null;
-    }
-    if (options.getCredentials().equals(NoCredentials.getInstance())) {
-      return null;
-    }
-    return MoreCallCredentials.from(options.getScopedCredentials());
-  }
-
-  private <S extends AbstractStub<S>> S withCredentials(S stub, CallCredentials credentials) {
-    if (credentials == null) {
-      return stub;
-    }
-    return stub.withCallCredentials(credentials);
-  }
-
-  private String projectName() {
-    return projectName;
-  }
-
-  @Override
-  public Paginated<InstanceConfig> listInstanceConfigs(int pageSize, @Nullable String pageToken)
-      throws SpannerException {
-    ListInstanceConfigsRequest.Builder request =
-        ListInstanceConfigsRequest.newBuilder().setParent(projectName()).setPageSize(0);
-    if (pageToken != null) {
-      request.setPageToken(pageToken);
-    }
-    ListInstanceConfigsResponse response =
-        get(
-            doUnaryCall(
-                InstanceAdminGrpc.getListInstanceConfigsMethod(),
-                request.build(),
-                projectName(),
-                null));
-    return new Paginated<>(response.getInstanceConfigsList(), response.getNextPageToken());
-  }
-
-  @Override
-  public InstanceConfig getInstanceConfig(String instanceConfigName) throws SpannerException {
-    GetInstanceConfigRequest request =
-        GetInstanceConfigRequest.newBuilder().setName(instanceConfigName).build();
-    return get(
-        doUnaryCall(InstanceAdminGrpc.getGetInstanceConfigMethod(), request, projectName(), null));
-  }
-
-  @Override
-  public Paginated<Instance> listInstances(
-      int pageSize, @Nullable String pageToken, @Nullable String filter) throws SpannerException {
-    ListInstancesRequest.Builder request =
-        ListInstancesRequest.newBuilder().setParent(projectName()).setPageSize(pageSize);
-    if (pageToken != null) {
-      request.setPageToken(pageToken);
-    }
-    if (filter != null) {
-      request.setFilter(filter);
-    }
-    ListInstancesResponse response =
-        get(
-            doUnaryCall(
-                InstanceAdminGrpc.getListInstancesMethod(), request.build(), projectName(), null));
-    return new Paginated<>(response.getInstancesList(), response.getNextPageToken());
-  }
-
-  @Override
-  public Operation createInstance(String parent, String instanceId, Instance instance)
-      throws SpannerException {
-    CreateInstanceRequest request =
-        CreateInstanceRequest.newBuilder()
-            .setParent(parent)
-            .setInstanceId(instanceId)
-            .setInstance(instance)
-            .build();
-    return get(doUnaryCall(InstanceAdminGrpc.getCreateInstanceMethod(), request, parent, null));
-  }
-
-  @Override
-  public Operation updateInstance(Instance instance, FieldMask fieldMask) throws SpannerException {
-    UpdateInstanceRequest request =
-        UpdateInstanceRequest.newBuilder().setInstance(instance).setFieldMask(fieldMask).build();
-    return get(
-        doUnaryCall(InstanceAdminGrpc.getUpdateInstanceMethod(), request, instance.getName(), null));
-  }
-
-  @Override
-  public Instance getInstance(String instanceName) throws SpannerException {
-    return get(
-        doUnaryCall(
-            InstanceAdminGrpc.getGetInstanceMethod(),
-            GetInstanceRequest.newBuilder().setName(instanceName).build(),
-            instanceName,
-            null));
-  }
-
-  @Override
-  public void deleteInstance(String instanceName) throws SpannerException {
-    get(
-        doUnaryCall(
-            InstanceAdminGrpc.getDeleteInstanceMethod(),
-            DeleteInstanceRequest.newBuilder().setName(instanceName).build(),
-            instanceName,
-            null));
-  }
-
-  @Override
-  public Paginated<Database> listDatabases(
-      String instanceName, int pageSize, @Nullable String pageToken) throws SpannerException {
-    ListDatabasesRequest.Builder builder =
-        ListDatabasesRequest.newBuilder().setParent(instanceName).setPageSize(pageSize);
-    if (pageToken != null) {
-      builder.setPageToken(pageToken);
-    }
-    com.google.spanner.admin.database.v1.ListDatabasesResponse response =
-        get(
-            doUnaryCall(
-                DatabaseAdminGrpc.getListDatabasesMethod(), builder.build(), instanceName, null));
-    return new Paginated<>(response.getDatabasesList(), response.getNextPageToken());
-  }
-
-  @Override
-  public Operation createDatabase(
-      String instanceName, String createDatabaseStatement, Iterable<String> additionalStatements)
-      throws SpannerException {
-    CreateDatabaseRequest request =
-        CreateDatabaseRequest.newBuilder()
-            .setParent(instanceName)
-            .setCreateStatement(createDatabaseStatement)
-            .addAllExtraStatements(additionalStatements)
-            .build();
-    return get(doUnaryCall(DatabaseAdminGrpc.getCreateDatabaseMethod(), request, instanceName, null));
-  }
-
-  @Override
-  public Operation updateDatabaseDdl(
-      String databaseName, Iterable<String> updateStatements, @Nullable String operationId)
-      throws SpannerException {
-    UpdateDatabaseDdlRequest request =
-        UpdateDatabaseDdlRequest.newBuilder()
-            .setDatabase(databaseName)
-            .addAllStatements(updateStatements)
-            .setOperationId(MoreObjects.firstNonNull(operationId, ""))
-            .build();
-    return get(
-        doUnaryCall(DatabaseAdminGrpc.getUpdateDatabaseDdlMethod(), request, databaseName, null));
-  }
-
-  @Override
-  public void dropDatabase(String databaseName) throws SpannerException {
-    get(
-        doUnaryCall(
-            DatabaseAdminGrpc.getDropDatabaseMethod(),
-            DropDatabaseRequest.newBuilder().setDatabase(databaseName).build(),
-            databaseName,
-            null));
-  }
-
-  @Override
-  public List<String> getDatabaseDdl(String databaseName) throws SpannerException {
-    GetDatabaseDdlRequest request =
-        GetDatabaseDdlRequest.newBuilder().setDatabase(databaseName).build();
-    return get(doUnaryCall(DatabaseAdminGrpc.getGetDatabaseDdlMethod(), request, databaseName, null))
-        .getStatementsList();
-  }
-
-  @Override
-  public Database getDatabase(String databaseName) throws SpannerException {
-    return get(
-        doUnaryCall(
-            DatabaseAdminGrpc.getGetDatabaseMethod(),
-            GetDatabaseRequest.newBuilder().setName(databaseName).build(),
-            databaseName,
-            null));
-  }
-
-  @Override
-  public Operation getOperation(String name) throws SpannerException {
-    GetOperationRequest request = GetOperationRequest.newBuilder().setName(name).build();
-    return get(doUnaryCall(OperationsGrpc.getGetOperationMethod(), request, name, null));
-  }
-
-  @Override
-  public Session createSession(
-      String databaseName, @Nullable Map<String, String> labels, @Nullable Map<Option, ?> options) {
-    CreateSessionRequest.Builder request =
-        CreateSessionRequest.newBuilder().setDatabase(databaseName);
-    if (labels != null && !labels.isEmpty()) {
-      Session.Builder session = Session.newBuilder().putAllLabels(labels);
-      request.setSession(session);
-    }
-    return get(
-        doUnaryCall(
-            SpannerGrpc.getCreateSessionMethod(),
-            request.build(),
-            databaseName,
-            Option.CHANNEL_HINT.getLong(options)));
-  }
-
-  @Override
-  public void deleteSession(String sessionName, @Nullable Map<Option, ?> options) {
-    DeleteSessionRequest request = DeleteSessionRequest.newBuilder().setName(sessionName).build();
-    get(
-        doUnaryCall(
-            SpannerGrpc.getDeleteSessionMethod(),
-            request,
-            sessionName,
-            Option.CHANNEL_HINT.getLong(options)));
-  }
-
-  @Override
-  public StreamingCall read(
-      ReadRequest request, ResultStreamConsumer consumer, @Nullable Map<Option, ?> options) {
-    return doStreamingCall(
-        SpannerGrpc.getStreamingReadMethod(),
-        request,
-        consumer,
-        request.getSession(),
-        Option.CHANNEL_HINT.getLong(options));
-  }
-
-  @Override
-  public ResultSet executeQuery(
-      ExecuteSqlRequest request, @Nullable Map<Option, ?> options) {
-    return get(
-        doUnaryCall(
-            SpannerGrpc.METHOD_EXECUTE_SQL,
-            request,
-            request.getSession(),
-            Option.CHANNEL_HINT.getLong(options)));
-  }
-
-  @Override
-  public StreamingCall executeQuery(
-      ExecuteSqlRequest request, ResultStreamConsumer consumer, @Nullable Map<Option, ?> options) {
-    return doStreamingCall(
-        SpannerGrpc.getExecuteStreamingSqlMethod(),
-        request,
-        consumer,
-        request.getSession(),
-        Option.CHANNEL_HINT.getLong(options));
-  }
-
-  @Override
-  public Transaction beginTransaction(
-      BeginTransactionRequest request, @Nullable Map<Option, ?> options) {
-    return get(
-        doUnaryCall(
-            SpannerGrpc.getBeginTransactionMethod(),
-            request,
-            request.getSession(),
-            Option.CHANNEL_HINT.getLong(options)));
-  }
-
-  @Override
-  public CommitResponse commit(CommitRequest commitRequest, @Nullable Map<Option, ?> options) {
-    return get(
-        doUnaryCall(
-            SpannerGrpc.getCommitMethod(),
-            commitRequest,
-            commitRequest.getSession(),
-            Option.CHANNEL_HINT.getLong(options)));
-  }
-
-  @Override
-  public void rollback(RollbackRequest request, @Nullable Map<Option, ?> options) {
-    get(
-        doUnaryCall(
-            SpannerGrpc.getRollbackMethod(),
-            request,
-            request.getSession(),
-            Option.CHANNEL_HINT.getLong(options)));
-  }
-
-  @Override
-  public PartitionResponse partitionQuery(
-      PartitionQueryRequest request, @Nullable Map<Option, ?> options)
-          throws SpannerException {
-    return get(
-        doUnaryCall(
-            SpannerGrpc.getPartitionQueryMethod(),
-            request,
-            request.getSession(),
-            Option.CHANNEL_HINT.getLong(options)));
-  }
-
-  @Override
-  public PartitionResponse partitionRead(
-      PartitionReadRequest request, @Nullable Map<Option, ?> options)
-          throws SpannerException {
-    return get(
-        doUnaryCall(
-            SpannerGrpc.getPartitionReadMethod(),
-            request,
-            request.getSession(),
-            Option.CHANNEL_HINT.getLong(options)));
-  }
-
-  /** Gets the result of an async RPC call, handling any exceptions encountered. */
-  private static <T> T get(final Future<T> future) throws SpannerException {
-    final Context context = Context.current();
-    try {
-      return future.get();
-    } catch (InterruptedException e) {
-      // We are the sole consumer of the future, so cancel it.
-      future.cancel(true);
-      throw SpannerExceptionFactory.propagateInterrupt(e);
-    } catch (ExecutionException | CancellationException e) {
-      throw newSpannerException(context, e);
-    }
-  }
-
-  private <ReqT, RespT> Future<RespT> doUnaryCall(
-      MethodDescriptor<ReqT, RespT> method,
-      ReqT request,
-      @Nullable String resource,
-      @Nullable Long channelHint) {
-    CallOptions callOptions =
-        credentials == null
-            ? CallOptions.DEFAULT
-            : CallOptions.DEFAULT.withCallCredentials(credentials);
-    final ClientCall<ReqT, RespT> call =
-        new MetadataClientCall<>(
-            pick(channelHint, channels).newCall(method, callOptions),
-            metadataProvider.newMetadata(resource, projectName()));
-    return ClientCalls.futureUnaryCall(call, request);
-  }
-
-  private <T> StreamingCall doStreamingCall(
-      MethodDescriptor<T, PartialResultSet> method,
-      T request,
-      ResultStreamConsumer consumer,
-      @Nullable String resource,
-      @Nullable Long channelHint) {
-    final Context context = Context.current();
-    // TODO: Add deadline based on context.
-    CallOptions callOptions =
-        credentials == null
-            ? CallOptions.DEFAULT
-            : CallOptions.DEFAULT.withCallCredentials(credentials);
-    final ClientCall<T, PartialResultSet> call =
-        new MetadataClientCall<>(
-            pick(channelHint, channels).newCall(method, callOptions),
-            metadataProvider.newMetadata(resource, projectName()));
-    ResultSetStreamObserver<T> observer = new ResultSetStreamObserver<T>(consumer, context, call);
-    ClientCalls.asyncServerStreamingCall(call, request, observer);
-    return observer;
-  }
-
-  @VisibleForTesting
-  static class MetadataClientCall<ReqT, RespT>
-      extends ForwardingClientCall.SimpleForwardingClientCall<ReqT, RespT> {
-    private final Metadata extraMetadata;
-
-    MetadataClientCall(ClientCall<ReqT, RespT> call, Metadata extraMetadata) {
-      super(call);
-      this.extraMetadata = extraMetadata;
-    }
-
-    @Override
-    public void start(Listener<RespT> responseListener, Metadata metadata) {
-      metadata.merge(extraMetadata);
-      super.start(responseListener, metadata);
-    }
-  }
-
-  private <T> T pick(@Nullable Long hint, List<T> elements) {
-    long hintVal = Math.abs(hint != null ? hint : random.nextLong());
-    long index = hintVal % elements.size();
-    return elements.get((int) index);
-  }
-
-  /**
-   * This is a one time setup for grpcz pages. This adds all of the methods to the Tracing
-   * environment required to show a consistent set of methods relating to Cloud Bigtable on the
-   * grpcz page.  If HBase artifacts are present, this will add tracing metadata for HBase methods.
-   *
-   * TODO: Remove this when we depend on gRPC 1.8
-   */
-  private static void setupTracingConfig() {
-    SampledSpanStore store = Tracing.getExportComponent().getSampledSpanStore();
-    if (store == null) {
-      // Tracing implementation is not linked.
-      return;
-    }
-    List<String> descriptors = new ArrayList<>();
-    addDescriptor(descriptors, SpannerGrpc.getServiceDescriptor());
-    addDescriptor(descriptors, DatabaseAdminGrpc.getServiceDescriptor());
-    addDescriptor(descriptors, InstanceAdminGrpc.getServiceDescriptor());
-    store.registerSpanNamesForCollection(descriptors);
-  }
-
-  /**
-   * Reads a list of {@link MethodDescriptor}s from a {@link ServiceDescriptor} and creates a list
-   * of Open Census tags.
-   */
-  private static void addDescriptor(List<String> descriptors, ServiceDescriptor serviceDescriptor) {
-    for (MethodDescriptor<?, ?> method : serviceDescriptor.getMethods()) {
-      // This is added by a grpc ClientInterceptor
-      descriptors.add("Sent." + method.getFullMethodName().replace('/', '.'));
-    }
-  }
-
-  private static class ResultSetStreamObserver<T>
-      implements ClientResponseObserver<T, PartialResultSet>, StreamingCall {
-    private final ResultStreamConsumer consumer;
-    private final Context context;
-    private final ClientCall<T, PartialResultSet> call;
-    private volatile ClientCallStreamObserver<T> requestStream;
-
-    public ResultSetStreamObserver(
-        ResultStreamConsumer consumer, Context context, ClientCall<T, PartialResultSet> call) {
-      this.consumer = consumer;
-      this.context = context;
-      this.call = call;
-    }
-
-    @Override
-    public void beforeStart(final ClientCallStreamObserver<T> requestStream) {
-      this.requestStream = requestStream;
-      requestStream.disableAutoInboundFlowControl();
-    }
-
-    @Override
-    public void onNext(PartialResultSet value) {
-      consumer.onPartialResultSet(value);
-    }
-
-    @Override
-    public void onError(Throwable t) {
-      consumer.onError(newSpannerException(context, t));
-    }
-
-    @Override
-    public void onCompleted() {
-      consumer.onCompleted();
-    }
-
-    @Override
-    public void request(int numMessages) {
-      requestStream.request(numMessages);
-    }
-
-    @Override
-    public void cancel(@Nullable String message) {
-      call.cancel(message, null);
-    }
-  }
-
-  private static class LoggingInterceptor implements ClientInterceptor {
-    private final Level level;
-
-    LoggingInterceptor(Level level) {
-      this.level = level;
-    }
-
-    private class CallLogger {
-      private final MethodDescriptor<?, ?> method;
-
-      CallLogger(MethodDescriptor<?, ?> method) {
-        this.method = method;
-      }
-
-      void log(String message) {
-        logger.log(
-            level,
-            "{0}[{1}]: {2}",
-            new Object[] {
-              method.getFullMethodName(),
-              Integer.toHexString(System.identityHashCode(this)),
-              message
-            });
-      }
-
-      void logfmt(String message, Object... params) {
-        log(String.format(message, params));
-      }
-    }
-
-    @Override
-    public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(
-        MethodDescriptor<ReqT, RespT> method, CallOptions callOptions, Channel next) {
-      if (!logger.isLoggable(level)) {
-        return next.newCall(method, callOptions);
-      }
-
-      final CallLogger callLogger = new CallLogger(method);
-      callLogger.log("Start");
-      return new ForwardingClientCall.SimpleForwardingClientCall<ReqT, RespT>(
-          next.newCall(method, callOptions)) {
-        @Override
-        public void start(Listener<RespT> responseListener, Metadata headers) {
-          super.start(
-              new ForwardingClientCallListener.SimpleForwardingClientCallListener<RespT>(
-                  responseListener) {
-                @Override
-                public void onMessage(RespT message) {
-                  callLogger.logfmt("Received:\n%s", message);
-                  super.onMessage(message);
-                }
-
-                @Override
-                public void onClose(Status status, Metadata trailers) {
-                  callLogger.logfmt("Closed with status %s and trailers %s", status, trailers);
-                  super.onClose(status, trailers);
-                }
-              },
-              headers);
-        }
-
-        @Override
-        public void sendMessage(ReqT message) {
-          callLogger.logfmt("Send:\n%s", message);
-          super.sendMessage(message);
-        }
-
-        @Override
-        public void cancel(@Nullable String message, @Nullable Throwable cause) {
-          callLogger.logfmt("Cancelled with message %s", message);
-          super.cancel(message, cause);
-        }
-      };
-    }
-  }
-}
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/LoggingInterceptor.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/LoggingInterceptor.java
new file mode 100644
index 000000000000..44571b1a6523
--- /dev/null
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/LoggingInterceptor.java
@@ -0,0 +1,108 @@
+/*
+ * Copyright 2018 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.cloud.spanner.spi.v1;
+
+import io.grpc.CallOptions;
+import io.grpc.Channel;
+import io.grpc.ClientCall;
+import io.grpc.ClientInterceptor;
+import io.grpc.ForwardingClientCall;
+import io.grpc.ForwardingClientCallListener;
+import io.grpc.Metadata;
+import io.grpc.MethodDescriptor;
+import io.grpc.Status;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import javax.annotation.Nullable;
+
+/** Adds logging to rpc calls */
+class LoggingInterceptor implements ClientInterceptor {
+
+  private final Logger logger;
+  private final Level level;
+
+  LoggingInterceptor(Logger logger, Level level) {
+    this.logger = logger;
+    this.level = level;
+  }
+
+  private class CallLogger {
+
+    private final MethodDescriptor<?, ?> method;
+
+    CallLogger(MethodDescriptor<?, ?> method) {
+      this.method = method;
+    }
+
+    void log(String message) {
+      logger.log(
+          level,
+          "{0}[{1}]: {2}",
+          new Object[] {
+            method.getFullMethodName(), Integer.toHexString(System.identityHashCode(this)), message
+          });
+    }
+
+    void logfmt(String message, Object... params) {
+      log(String.format(message, params));
+    }
+  }
+
+  @Override
+  public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(
+      MethodDescriptor<ReqT, RespT> method, CallOptions callOptions, Channel next) {
+    if (!logger.isLoggable(level)) {
+      return next.newCall(method, callOptions);
+    }
+
+    final CallLogger callLogger = new CallLogger(method);
+    callLogger.log("Start");
+    return new ForwardingClientCall.SimpleForwardingClientCall<ReqT, RespT>(
+        next.newCall(method, callOptions)) {
+      @Override
+      public void start(Listener<RespT> responseListener, Metadata headers) {
+        super.start(
+            new ForwardingClientCallListener.SimpleForwardingClientCallListener<RespT>(
+                responseListener) {
+              @Override
+              public void onMessage(RespT message) {
+                callLogger.logfmt("Received:\n%s", message);
+                super.onMessage(message);
+              }
+
+              @Override
+              public void onClose(Status status, Metadata trailers) {
+                callLogger.logfmt("Closed with status %s and trailers %s", status, trailers);
+                super.onClose(status, trailers);
+              }
+            },
+            headers);
+      }
+
+      @Override
+      public void sendMessage(ReqT message) {
+        callLogger.logfmt("Send:\n%s", message);
+        super.sendMessage(message);
+      }
+
+      @Override
+      public void cancel(@Nullable String message, @Nullable Throwable cause) {
+        callLogger.logfmt("Cancelled with message %s", message);
+        super.cancel(message, cause);
+      }
+    };
+  }
+}
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/SpannerInterceptorProvider.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/SpannerInterceptorProvider.java
new file mode 100644
index 000000000000..c51966837d00
--- /dev/null
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/SpannerInterceptorProvider.java
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2018 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.cloud.spanner.spi.v1;
+
+import com.google.api.core.InternalApi;
+import com.google.api.gax.grpc.GrpcInterceptorProvider;
+import com.google.common.collect.ImmutableList;
+import io.grpc.ClientInterceptor;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * For internal use only. An interceptor provider that provides a list of grpc interceptors for
+ * {@code GapicSpannerRpc} to handle logging and error augmentation by intercepting grpc calls.
+ */
+@InternalApi("Exposed for testing")
+public class SpannerInterceptorProvider implements GrpcInterceptorProvider {
+
+  private static final List<ClientInterceptor> defaultInterceptors =
+      ImmutableList.of(
+          new SpannerErrorInterceptor(),
+          new LoggingInterceptor(Logger.getLogger(GapicSpannerRpc.class.getName()), Level.FINER),
+          WatchdogInterceptor.newDefaultWatchdogInterceptor());
+
+  private final List<ClientInterceptor> clientInterceptors;
+
+  private SpannerInterceptorProvider(List<ClientInterceptor> clientInterceptors) {
+    this.clientInterceptors = clientInterceptors;
+  }
+
+  public static SpannerInterceptorProvider createDefault() {
+    return new SpannerInterceptorProvider(defaultInterceptors);
+  }
+
+  public SpannerInterceptorProvider with(ClientInterceptor clientInterceptor) {
+    List<ClientInterceptor> interceptors =
+        ImmutableList.<ClientInterceptor>builder()
+            .addAll(this.clientInterceptors)
+            .add(clientInterceptor)
+            .build();
+    return new SpannerInterceptorProvider(interceptors);
+  }
+
+  @Override
+  public List<ClientInterceptor> getInterceptors() {
+    return clientInterceptors;
+  }
+}
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/SpannerMetadataProvider.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/SpannerMetadataProvider.java
index f80eb90b12c1..7bbe6a31a1e7 100644
--- a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/SpannerMetadataProvider.java
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/SpannerMetadataProvider.java
@@ -18,16 +18,16 @@
 import com.google.common.collect.ImmutableMap;
 import io.grpc.Metadata;
 import io.grpc.Metadata.Key;
+import java.util.Arrays;
+import java.util.List;
 import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-/**
- * For internal use only.
- */
+/** For internal use only. */
 class SpannerMetadataProvider {
   private final Map<Metadata.Key<String>, String> headers;
-  private final Key<String> resourceHeaderKey;
+  private final String resourceHeaderKey;
 
   private static final Pattern[] RESOURCE_TOKEN_PATTERNS = {
     Pattern.compile("^(?<headerValue>projects/[^/]*/instances/[^/]*/databases/[^/]*)(.*)?"),
@@ -35,7 +35,7 @@ class SpannerMetadataProvider {
   };
 
   private SpannerMetadataProvider(Map<String, String> headers, String resourceHeaderKey) {
-    this.resourceHeaderKey = Key.of(resourceHeaderKey, Metadata.ASCII_STRING_MARSHALLER);
+    this.resourceHeaderKey = resourceHeaderKey;
     this.headers = constructHeadersAsMetadata(headers);
   }
 
@@ -50,11 +50,21 @@ Metadata newMetadata(String resourceTokenTemplate, String defaultResourceToken)
     }
 
     metadata.put(
-        resourceHeaderKey, getResourceHeaderValue(resourceTokenTemplate, defaultResourceToken));
+        Key.of(resourceHeaderKey, Metadata.ASCII_STRING_MARSHALLER),
+        getResourceHeaderValue(resourceTokenTemplate, defaultResourceToken));
 
     return metadata;
   }
 
+  Map<String, List<String>> newExtraHeaders(
+      String resourceTokenTemplate, String defaultResourceToken) {
+    return ImmutableMap.<String, List<String>>builder()
+        .put(
+            resourceHeaderKey,
+            Arrays.asList(getResourceHeaderValue(resourceTokenTemplate, defaultResourceToken)))
+        .build();
+  }
+
   private Map<Metadata.Key<String>, String> constructHeadersAsMetadata(
       Map<String, String> headers) {
     ImmutableMap.Builder<Metadata.Key<String>, String> headersAsMetadataBuilder =
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/SpannerRpc.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/SpannerRpc.java
index c07a80af8ae8..558311c2215c 100644
--- a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/SpannerRpc.java
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/SpannerRpc.java
@@ -16,15 +16,21 @@
 
 package com.google.cloud.spanner.spi.v1;
 
+import com.google.api.gax.longrunning.OperationFuture;
 import com.google.cloud.ServiceRpc;
 import com.google.cloud.spanner.SpannerException;
 import com.google.cloud.spanner.spi.v1.SpannerRpc.Option;
 import com.google.common.collect.ImmutableList;
 import com.google.longrunning.Operation;
+import com.google.protobuf.Empty;
 import com.google.protobuf.FieldMask;
+import com.google.spanner.admin.database.v1.CreateDatabaseMetadata;
 import com.google.spanner.admin.database.v1.Database;
+import com.google.spanner.admin.database.v1.UpdateDatabaseDdlMetadata;
+import com.google.spanner.admin.instance.v1.CreateInstanceMetadata;
 import com.google.spanner.admin.instance.v1.Instance;
 import com.google.spanner.admin.instance.v1.InstanceConfig;
+import com.google.spanner.admin.instance.v1.UpdateInstanceMetadata;
 import com.google.spanner.v1.BeginTransactionRequest;
 import com.google.spanner.v1.CommitRequest;
 import com.google.spanner.v1.CommitResponse;
@@ -163,10 +169,11 @@ Paginated<InstanceConfig> listInstanceConfigs(int pageSize, @Nullable String pag
   Paginated<Instance> listInstances(
       int pageSize, @Nullable String pageToken, @Nullable String filter) throws SpannerException;
 
-  Operation createInstance(String parent, String instanceId, Instance instance)
-      throws SpannerException;
+  OperationFuture<Instance, CreateInstanceMetadata> createInstance(
+      String parent, String instanceId, Instance instance) throws SpannerException;
 
-  Operation updateInstance(Instance instance, FieldMask fieldMask) throws SpannerException;
+  OperationFuture<Instance, UpdateInstanceMetadata> updateInstance(
+      Instance instance, FieldMask fieldMask) throws SpannerException;
 
   Instance getInstance(String instanceName) throws SpannerException;
 
@@ -176,11 +183,11 @@ Operation createInstance(String parent, String instanceId, Instance instance)
   Paginated<Database> listDatabases(String instanceName, int pageSize, @Nullable String pageToken)
       throws SpannerException;
 
-  Operation createDatabase(
+  OperationFuture<Database, CreateDatabaseMetadata> createDatabase(
       String instanceName, String createDatabaseStatement, Iterable<String> additionalStatements)
       throws SpannerException;
 
-  Operation updateDatabaseDdl(
+  OperationFuture<Empty, UpdateDatabaseDdlMetadata> updateDatabaseDdl(
       String databaseName, Iterable<String> updateDatabaseStatements, @Nullable String updateId)
       throws SpannerException;
 
@@ -218,7 +225,8 @@ PartitionResponse partitionQuery(
       PartitionQueryRequest request, @Nullable Map<Option, ?> options)
       throws SpannerException;
 
-  PartitionResponse partitionRead(
-      PartitionReadRequest request, @Nullable Map<Option, ?> options)
+  PartitionResponse partitionRead(PartitionReadRequest request, @Nullable Map<Option, ?> options)
       throws SpannerException;
+
+  public void shutdown();
 }
diff --git a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/testing/RemoteSpannerHelper.java b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/testing/RemoteSpannerHelper.java
index 73ae5f05ceaf..09a314464295 100644
--- a/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/testing/RemoteSpannerHelper.java
+++ b/google-cloud-clients/google-cloud-spanner/src/main/java/com/google/cloud/spanner/testing/RemoteSpannerHelper.java
@@ -16,13 +16,14 @@
 
 package com.google.cloud.spanner.testing;
 
+import com.google.api.gax.longrunning.OperationFuture;
 import com.google.cloud.spanner.BatchClient;
 import com.google.cloud.spanner.Database;
 import com.google.cloud.spanner.DatabaseClient;
 import com.google.cloud.spanner.InstanceId;
-import com.google.cloud.spanner.Operation;
 import com.google.cloud.spanner.Spanner;
 import com.google.cloud.spanner.SpannerException;
+import com.google.cloud.spanner.SpannerExceptionFactory;
 import com.google.cloud.spanner.SpannerOptions;
 import com.google.spanner.admin.database.v1.CreateDatabaseMetadata;
 import java.util.ArrayList;
@@ -95,13 +96,18 @@ public String getUniqueDatabaseId() {
    */
   public Database createTestDatabase(Iterable<String> statements) throws SpannerException {
     String dbId = getUniqueDatabaseId();
-    Operation<Database, CreateDatabaseMetadata> op =
-        client.getDatabaseAdminClient().createDatabase(instanceId.getInstance(), dbId, statements);
-    op = op.waitFor();
-    Database db = op.getResult();
-    logger.log(Level.FINE, "Created test database {0}", db.getId());
-    dbs.add(db);
-    return db;
+    try {
+      OperationFuture<Database, CreateDatabaseMetadata> op =
+          client
+              .getDatabaseAdminClient()
+              .createDatabase(instanceId.getInstance(), dbId, statements);
+      Database db = op.get();
+      logger.log(Level.FINE, "Created test database {0}", db.getId());
+      dbs.add(db);
+      return db;
+    } catch (Exception e) {
+      throw SpannerExceptionFactory.newSpannerException(e);
+    }
   }
 
   /** Deletes all the databases created via {@code createTestDatabase}. Shuts down the client. */
diff --git a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/BatchClientImplTest.java b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/BatchClientImplTest.java
index f7a0c95acfe3..395e11cbea7b 100644
--- a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/BatchClientImplTest.java
+++ b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/BatchClientImplTest.java
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
- 
+
 package com.google.cloud.spanner;
 
 import static com.google.common.truth.Truth.assertThat;
@@ -48,7 +48,7 @@ public final class BatchClientImplTest {
   private static final ByteString TXN_ID = ByteString.copyFromUtf8("my-txn");
   private static final String TIMESTAMP = "2017-11-15T10:54:20Z";
 
-  @Mock private SpannerRpc rpc;
+  @Mock private SpannerRpc gapicRpc;
   @Mock private SpannerOptions spannerOptions;
   @Captor private ArgumentCaptor<Map<SpannerRpc.Option, Object>> optionsCaptor;
   @Mock private BatchTransactionId txnID;
@@ -59,20 +59,21 @@ public final class BatchClientImplTest {
   public void setUp() {
     initMocks(this);
     DatabaseId db = DatabaseId.of(DB_NAME);
-    SpannerImpl spanner = new SpannerImpl(rpc, 1, spannerOptions);
+    SpannerImpl spanner = new SpannerImpl(gapicRpc, 1, spannerOptions);
     client = new BatchClientImpl(db, spanner);
   }
 
   @Test
   public void testBatchReadOnlyTxnWithBound() throws Exception {
     Session sessionProto = Session.newBuilder().setName(SESSION_NAME).build();
-    when(rpc.createSession(eq(DB_NAME), (Map<String, String>) anyMap(), optionsCaptor.capture()))
+    when(gapicRpc.createSession(
+            eq(DB_NAME), (Map<String, String>) anyMap(), optionsCaptor.capture()))
         .thenReturn(sessionProto);
     com.google.protobuf.Timestamp timestamp = Timestamps.parse(TIMESTAMP);
     Transaction txnMetadata =
         Transaction.newBuilder().setId(TXN_ID).setReadTimestamp(timestamp).build();
-    when(spannerOptions.getSpannerRpcV1()).thenReturn(rpc);
-    when(rpc.beginTransaction(Mockito.<BeginTransactionRequest>any(), optionsCaptor.capture()))
+    when(spannerOptions.getSpannerRpcV1()).thenReturn(gapicRpc);
+    when(gapicRpc.beginTransaction(Mockito.<BeginTransactionRequest>any(), optionsCaptor.capture()))
         .thenReturn(txnMetadata);
 
     BatchReadOnlyTransaction batchTxn = client.batchReadOnlyTransaction(TimestampBound.strong());
diff --git a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/DatabaseAdminClientImplTest.java b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/DatabaseAdminClientImplTest.java
index a39630732386..8baa98d7ac32 100644
--- a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/DatabaseAdminClientImplTest.java
+++ b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/DatabaseAdminClientImplTest.java
@@ -21,11 +21,13 @@
 import static org.mockito.Mockito.when;
 import static org.mockito.MockitoAnnotations.initMocks;
 
+import com.google.api.gax.longrunning.OperationFuture;
 import com.google.cloud.spanner.spi.v1.SpannerRpc;
 import com.google.cloud.spanner.spi.v1.SpannerRpc.Paginated;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Lists;
 import com.google.protobuf.Any;
+import com.google.protobuf.Empty;
 import com.google.protobuf.Message;
 import com.google.spanner.admin.database.v1.CreateDatabaseMetadata;
 import com.google.spanner.admin.database.v1.Database;
@@ -82,45 +84,54 @@ public void getDatabase() {
   }
 
   @Test
-  public void createDatabase() {
+  public void createDatabase() throws Exception {
+    OperationFuture<Database, CreateDatabaseMetadata> rawOperationFuture =
+        OperationFutureUtil.immediateOperationFuture(
+            "createDatabase", getDatabaseProto(), CreateDatabaseMetadata.getDefaultInstance());
     when(rpc.createDatabase(
             INSTANCE_NAME, "CREATE DATABASE `" + DB_ID + "`", Collections.<String>emptyList()))
-        .thenReturn(
-            com.google.longrunning.Operation.newBuilder()
-                .setDone(true)
-                .setName("my-op")
-                .setResponse(toAny(getDatabaseProto()))
-                .build());
-    Operation<com.google.cloud.spanner.Database, CreateDatabaseMetadata> op =
+        .thenReturn(rawOperationFuture);
+    OperationFuture<com.google.cloud.spanner.Database, CreateDatabaseMetadata> op =
         client.createDatabase(INSTANCE_ID, DB_ID, Collections.<String>emptyList());
     assertThat(op.isDone()).isTrue();
-    assertThat(op.getResult().getId().getName()).isEqualTo(DB_NAME);
+    assertThat(op.get().getId().getName()).isEqualTo(DB_NAME);
   }
 
   @Test
-  public void updateDatabaseDdl() {
+  public void updateDatabaseDdl() throws Exception {
     String opName = DB_NAME + "/operations/myop";
     String opId = "myop";
     List<String> ddl = ImmutableList.of();
-    when(rpc.updateDatabaseDdl(DB_NAME, ddl, opId))
-        .thenReturn(
-            com.google.longrunning.Operation.newBuilder().setDone(true).setName(opName).build());
-    Operation<Void, UpdateDatabaseDdlMetadata> op =
+    OperationFuture<Empty, UpdateDatabaseDdlMetadata> rawOperationFuture =
+        OperationFutureUtil.immediateOperationFuture(
+            opName, Empty.getDefaultInstance(), UpdateDatabaseDdlMetadata.getDefaultInstance());
+    when(rpc.updateDatabaseDdl(DB_NAME, ddl, opId)).thenReturn(rawOperationFuture);
+    OperationFuture<Void, UpdateDatabaseDdlMetadata> op =
         client.updateDatabaseDdl(INSTANCE_ID, DB_ID, ddl, opId);
     assertThat(op.isDone()).isTrue();
     assertThat(op.getName()).isEqualTo(opName);
   }
 
   @Test
-  public void updateDatabaseDdlOpAlreadyExists() {
-    String opName = DB_NAME + "/operations/myop";
-    String opId = "myop";
+  public void updateDatabaseDdlOpAlreadyExists() throws Exception {
+    String originalOpName = DB_NAME + "/operations/originalop";
     List<String> ddl = ImmutableList.of();
-    when(rpc.updateDatabaseDdl(DB_NAME, ddl, opId))
-        .thenThrow(SpannerExceptionFactory.newSpannerException(ErrorCode.ALREADY_EXISTS, ""));
-    Operation<Void, UpdateDatabaseDdlMetadata> op =
-        client.updateDatabaseDdl(INSTANCE_ID, DB_ID, ddl, opId);
-    assertThat(op.getName()).isEqualTo(opName);
+    OperationFuture<Empty, UpdateDatabaseDdlMetadata> originalOp =
+        OperationFutureUtil.immediateOperationFuture(
+            originalOpName,
+            Empty.getDefaultInstance(),
+            UpdateDatabaseDdlMetadata.getDefaultInstance());
+
+    String newOpName = DB_NAME + "/operations/newop";
+    String newOpId = "newop";
+    OperationFuture<Empty, UpdateDatabaseDdlMetadata> newop =
+        OperationFutureUtil.immediateOperationFuture(
+            newOpName, Empty.getDefaultInstance(), UpdateDatabaseDdlMetadata.getDefaultInstance());
+
+    when(rpc.updateDatabaseDdl(DB_NAME, ddl, newOpId)).thenReturn(originalOp);
+    OperationFuture<Void, UpdateDatabaseDdlMetadata> op =
+        client.updateDatabaseDdl(INSTANCE_ID, DB_ID, ddl, newOpId);
+    assertThat(op.getName()).isEqualTo(originalOpName);
   }
 
   @Test
diff --git a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/GceTestEnvConfig.java b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/GceTestEnvConfig.java
index 422d9b43f525..b49fb1ef5d70 100644
--- a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/GceTestEnvConfig.java
+++ b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/GceTestEnvConfig.java
@@ -18,7 +18,7 @@
 
 import static com.google.common.base.Preconditions.checkState;
 
-import com.google.common.collect.ImmutableList;
+import com.google.cloud.spanner.spi.v1.SpannerInterceptorProvider;
 import io.grpc.CallOptions;
 import io.grpc.Channel;
 import io.grpc.ClientCall;
@@ -55,10 +55,9 @@ public GceTestEnvConfig() {
     }
     options =
         builder
-            .setRpcChannelFactory(
-                new SpannerOptions.NettyRpcChannelFactory(
-                    null,
-                    ImmutableList.<ClientInterceptor>of(new GrpcErrorInjector(errorProbability))))
+            .setInterceptorProvider(
+                SpannerInterceptorProvider.createDefault()
+                    .with(new GrpcErrorInjector(errorProbability)))
             .build();
   }
 
diff --git a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/InstanceAdminClientImplTest.java b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/InstanceAdminClientImplTest.java
index c9b31f9d2264..7fb451f508c5 100644
--- a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/InstanceAdminClientImplTest.java
+++ b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/InstanceAdminClientImplTest.java
@@ -21,6 +21,7 @@
 import static org.mockito.Mockito.when;
 import static org.mockito.MockitoAnnotations.initMocks;
 
+import com.google.api.gax.longrunning.OperationFuture;
 import com.google.cloud.spanner.spi.v1.SpannerRpc;
 import com.google.cloud.spanner.spi.v1.SpannerRpc.Paginated;
 import com.google.common.collect.ImmutableList;
@@ -100,22 +101,21 @@ private com.google.spanner.admin.instance.v1.Instance getAnotherInstanceProto()
   }
 
   @Test
-  public void createInstance() {
+  public void createInstance() throws Exception {
+    OperationFuture<com.google.spanner.admin.instance.v1.Instance, CreateInstanceMetadata>
+        rawOperationFuture =
+            OperationFutureUtil.immediateOperationFuture(
+                "createInstance", getInstanceProto(), CreateInstanceMetadata.getDefaultInstance());
     when(rpc.createInstance("projects/" + PROJECT_ID, INSTANCE_ID, getInstanceProto()))
-        .thenReturn(
-            com.google.longrunning.Operation.newBuilder()
-                .setDone(true)
-                .setName(INSTANCE_NAME + "/operations/op")
-                .setResponse(DatabaseAdminClientImplTest.toAny(getInstanceProto()))
-                .build());
-    Operation<Instance, CreateInstanceMetadata> op =
+        .thenReturn(rawOperationFuture);
+    OperationFuture<Instance, CreateInstanceMetadata> op =
         client.createInstance(
             InstanceInfo.newBuilder(InstanceId.of(PROJECT_ID, INSTANCE_ID))
                 .setInstanceConfigId(InstanceConfigId.of(PROJECT_ID, CONFIG_ID))
                 .setNodeCount(1)
                 .build());
     assertThat(op.isDone()).isTrue();
-    assertThat(op.getResult().getId().getName()).isEqualTo(INSTANCE_NAME);
+    assertThat(op.get().getId().getName()).isEqualTo(INSTANCE_NAME);
   }
 
   @Test
@@ -131,29 +131,28 @@ public void dropInstance() {
   }
 
   @Test
-  public void updateInstanceMetadata() {
+  public void updateInstanceMetadata() throws Exception {
     com.google.spanner.admin.instance.v1.Instance instance =
         com.google.spanner.admin.instance.v1.Instance.newBuilder()
             .setName(INSTANCE_NAME)
             .setConfig(CONFIG_NAME)
             .setNodeCount(2)
             .build();
+    OperationFuture<com.google.spanner.admin.instance.v1.Instance, UpdateInstanceMetadata>
+        rawOperationFuture =
+            OperationFutureUtil.immediateOperationFuture(
+                "updateInstance", getInstanceProto(), UpdateInstanceMetadata.getDefaultInstance());
     when(rpc.updateInstance(instance, FieldMask.newBuilder().addPaths("node_count").build()))
-        .thenReturn(
-            com.google.longrunning.Operation.newBuilder()
-                .setDone(true)
-                .setName(INSTANCE_NAME + "/operations/op")
-                .setResponse(DatabaseAdminClientImplTest.toAny(instance))
-                .build());
+        .thenReturn(rawOperationFuture);
     InstanceInfo instanceInfo =
         InstanceInfo.newBuilder(InstanceId.of(INSTANCE_NAME))
             .setInstanceConfigId(InstanceConfigId.of(CONFIG_NAME))
             .setNodeCount(2)
             .build();
-    Operation<Instance, UpdateInstanceMetadata> op =
+    OperationFuture<Instance, UpdateInstanceMetadata> op =
         client.updateInstance(instanceInfo, InstanceInfo.InstanceField.NODE_COUNT);
     assertThat(op.isDone()).isTrue();
-    assertThat(op.getResult().getId().getName()).isEqualTo(INSTANCE_NAME);
+    assertThat(op.get().getId().getName()).isEqualTo(INSTANCE_NAME);
   }
 
   @Test
diff --git a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/IntegrationTestEnv.java b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/IntegrationTestEnv.java
index 1bfb6c8372e0..88999969d4c1 100644
--- a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/IntegrationTestEnv.java
+++ b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/IntegrationTestEnv.java
@@ -18,14 +18,14 @@
 
 import static com.google.common.base.Preconditions.checkState;
 
-import com.google.cloud.RetryOption;
+import com.google.api.gax.longrunning.OperationFuture;
 import com.google.cloud.spanner.testing.RemoteSpannerHelper;
 import com.google.common.collect.Iterators;
 import com.google.spanner.admin.instance.v1.CreateInstanceMetadata;
+import java.util.concurrent.TimeUnit;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import org.junit.rules.ExternalResource;
-import org.threeten.bp.Duration;
 
 /**
  * JUnit 4 test rule that provides access to a Cloud Spanner instance to use for tests, and allows
@@ -113,9 +113,14 @@ private void initializeInstance(InstanceId instanceId) {
             .setDisplayName("Test instance")
             .setInstanceConfigId(configId)
             .build();
-    Operation<Instance, CreateInstanceMetadata> op = instanceAdminClient.createInstance(instance);
-    op = op.waitFor(RetryOption.initialRetryDelay(Duration.ofMillis(500L)));
-    Instance createdInstance = op.getResult();
+    OperationFuture<Instance, CreateInstanceMetadata> op =
+        instanceAdminClient.createInstance(instance);
+    Instance createdInstance;
+    try {
+      createdInstance = op.get(500L, TimeUnit.MILLISECONDS);
+    } catch (Exception e) {
+      throw SpannerExceptionFactory.newSpannerException(e);
+    }
     logger.log(Level.INFO, "Created test instance: {0}", createdInstance.getId());
   }
 
diff --git a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/OperationFutureUtil.java b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/OperationFutureUtil.java
new file mode 100644
index 000000000000..43471b5b700b
--- /dev/null
+++ b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/OperationFutureUtil.java
@@ -0,0 +1,275 @@
+/*
+ * Copyright 2018 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.cloud.spanner;
+
+import com.google.api.core.ApiFuture;
+import com.google.api.core.ApiFutures;
+import com.google.api.gax.longrunning.OperationFuture;
+import com.google.api.gax.longrunning.OperationSnapshot;
+import com.google.api.gax.retrying.RetryingFuture;
+import com.google.api.gax.retrying.TimedAttemptSettings;
+import com.google.api.gax.rpc.StatusCode;
+import com.google.common.base.Preconditions;
+import com.google.protobuf.Any;
+import com.google.protobuf.Message;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executor;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+// TODO(hzyi): add a public FakeOperationSnapshot in gax to support testing
+class OperationFutureUtil {
+
+  private OperationFutureUtil() {
+    // Utility class
+  }
+
+  public static class FakeStatusCode implements StatusCode {
+    private final Code code;
+
+    public FakeStatusCode(Code code) {
+      this.code = code;
+    }
+
+    @Override
+    public Code getCode() {
+      return code;
+    }
+
+    @Override
+    public Code getTransportCode() {
+      return getCode();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      if (this == o) {
+        return true;
+      }
+      if (o == null || getClass() != o.getClass()) {
+        return false;
+      }
+
+      FakeStatusCode that = (FakeStatusCode) o;
+
+      return code == that.code;
+    }
+
+    @Override
+    public int hashCode() {
+      return code != null ? code.hashCode() : 0;
+    }
+
+    public static FakeStatusCode of(Code code) {
+      return new FakeStatusCode(code);
+    }
+  }
+
+  public static final <ResponseT extends Message, MetadataT extends Message>
+      OperationSnapshot completedSnapshot(
+          final String name, final ResponseT response, final MetadataT metadata) {
+    return new OperationSnapshot() {
+      @Override
+      public String getName() {
+        return name;
+      }
+
+      @Override
+      public Object getMetadata() {
+        return Any.pack(metadata);
+      }
+
+      @Override
+      public Object getResponse() {
+        return Any.pack(response);
+      }
+
+      @Override
+      public boolean isDone() {
+        return true;
+      }
+
+      @Override
+      public StatusCode getErrorCode() {
+        return FakeStatusCode.of(StatusCode.Code.OK);
+      }
+
+      @Override
+      public String getErrorMessage() {
+        return null;
+      }
+    };
+  }
+
+  /** Already-completed {@code ImmediateRetryingFuture}, useful for testing. */
+  public static final class ImmediateRetryingFuture<V> implements RetryingFuture<V> {
+
+    private final ApiFuture<V> immediateFuture;
+    private ApiFuture<V> attemptFuture;
+
+    ImmediateRetryingFuture(V response) {
+      this.immediateFuture = ApiFutures.immediateFuture(response);
+    }
+
+    @Override
+    public void addListener(Runnable runnable, Executor executor) {
+      immediateFuture.addListener(runnable, executor);
+    }
+
+    @Override
+    public V get(long time, TimeUnit unit)
+        throws ExecutionException, InterruptedException, TimeoutException {
+      return get();
+    }
+
+    @Override
+    public V get() throws ExecutionException, InterruptedException {
+      return immediateFuture.get();
+    }
+
+    @Override
+    public boolean isDone() {
+      return true;
+    }
+
+    @Override
+    public boolean isCancelled() {
+      return false;
+    }
+
+    @Override
+    public boolean cancel(boolean b) {
+      return false;
+    }
+
+    @Override
+    public void setAttemptFuture(ApiFuture<V> attemptFuture) {
+      this.attemptFuture = attemptFuture;
+    }
+
+    @Override
+    public ApiFuture<V> getAttemptResult() {
+      return this.attemptFuture;
+    }
+
+    @Override
+    public TimedAttemptSettings getAttemptSettings() {
+      throw new UnsupportedOperationException("Not implemented: getAttemptSettings()");
+    }
+
+    @Override
+    public Callable<V> getCallable() {
+      throw new UnsupportedOperationException("Not implemented: getCallable()");
+    }
+
+    @Override
+    public ApiFuture<V> peekAttemptResult() {
+      return this.attemptFuture;
+    }
+  }
+
+  public static final <ResponseT> RetryingFuture<ResponseT> immediateRetryingFuture(
+      final ResponseT response) {
+    return new ImmediateRetryingFuture(response);
+  }
+
+  public static final <ResponseT extends Message, MetadataT extends Message>
+      OperationFuture<ResponseT, MetadataT> immediateOperationFuture(
+          final String name, final ResponseT response, final MetadataT metadata) {
+    return immediateOperationFuture(completedSnapshot(name, response, metadata));
+  }
+
+  /**
+   * Creates an already-completed {@code OperationFuture}, useful for testing.
+   *
+   * <p>{@code completedSnapshot.isDone()} must return true. The snapshot's {@code getResponse()}
+   * and {@code getMetadata()} must be instances of {@code ResponseT} and {@code MetadataT},
+   * respectively.
+   */
+  @SuppressWarnings("unchecked")
+  public static final <ResponseT, MetadataT>
+      OperationFuture<ResponseT, MetadataT> immediateOperationFuture(
+          final OperationSnapshot completedSnapshot) {
+
+    Preconditions.checkArgument(
+        completedSnapshot.isDone(), "given snapshot must already be completed");
+    final ApiFuture<MetadataT> metadataFuture =
+        ApiFutures.immediateFuture((MetadataT) completedSnapshot.getMetadata());
+    final ApiFuture<OperationSnapshot> initialFuture =
+        ApiFutures.immediateFuture(completedSnapshot);
+    final RetryingFuture<OperationSnapshot> pollingFuture =
+        immediateRetryingFuture(completedSnapshot);
+
+    return new OperationFuture<ResponseT, MetadataT>() {
+      @Override
+      public String getName() {
+        return completedSnapshot.getName();
+      }
+
+      @Override
+      public ApiFuture<MetadataT> getMetadata() {
+        return metadataFuture;
+      }
+
+      @Override
+      public ApiFuture<MetadataT> peekMetadata() {
+        return metadataFuture;
+      }
+
+      @Override
+      public ApiFuture<OperationSnapshot> getInitialFuture() {
+        return initialFuture;
+      }
+
+      @Override
+      public RetryingFuture<OperationSnapshot> getPollingFuture() {
+        return pollingFuture;
+      }
+
+      @Override
+      public void addListener(Runnable runnable, Executor executor) {
+        pollingFuture.addListener(runnable, executor);
+      }
+
+      @Override
+      public ResponseT get(long time, TimeUnit unit)
+          throws ExecutionException, InterruptedException, TimeoutException {
+        return get();
+      }
+
+      @Override
+      public ResponseT get() throws ExecutionException, InterruptedException {
+        return (ResponseT) pollingFuture.get().getResponse();
+      }
+
+      @Override
+      public boolean isDone() {
+        return true;
+      }
+
+      @Override
+      public boolean isCancelled() {
+        return false;
+      }
+
+      @Override
+      public boolean cancel(boolean b) {
+        return false;
+      }
+    };
+  }
+}
diff --git a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/SpannerOptionsTest.java b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/SpannerOptionsTest.java
index 731cd1270d8d..1cc406b8a851 100644
--- a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/SpannerOptionsTest.java
+++ b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/SpannerOptionsTest.java
@@ -18,13 +18,9 @@
 
 import static com.google.common.truth.Truth.assertThat;
 
+import com.google.cloud.TransportOptions;
 import java.util.HashMap;
 import java.util.Map;
-
-import com.google.cloud.TransportOptions;
-
-import io.grpc.ManagedChannel;
-import io.grpc.netty.shaded.io.grpc.netty.NettyChannelBuilder;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
@@ -36,26 +32,13 @@
 @RunWith(JUnit4.class)
 public class SpannerOptionsTest {
 
-  @Rule
-  public ExpectedException thrown = ExpectedException.none();
-
-  private static class TestChannelFactory implements SpannerOptions.RpcChannelFactory {
-    @Override
-    public ManagedChannel newChannel(String host, int port) {
-      // Disable SSL to avoid a dependency on ALPN/NPN.
-      return NettyChannelBuilder.forAddress(host, port).usePlaintext(true).build();
-    }
-  }
+  @Rule public ExpectedException thrown = ExpectedException.none();
 
   @Test
   public void defaultBuilder() {
     // We need to set the project id since in test environment we cannot obtain a default project
     // id.
-    SpannerOptions options =
-        SpannerOptions.newBuilder()
-            .setProjectId("test-project")
-            .setRpcChannelFactory(new TestChannelFactory())
-            .build();
+    SpannerOptions options = SpannerOptions.newBuilder().setProjectId("test-project").build();
     assertThat(options.getHost()).isEqualTo("https://spanner.googleapis.com");
     assertThat(options.getPrefetchChunks()).isEqualTo(4);
     assertThat(options.getSessionLabels()).isNull();
@@ -69,7 +52,6 @@ public void builder() {
     labels.put("env", "dev");
     SpannerOptions options =
         SpannerOptions.newBuilder()
-            .setRpcChannelFactory(new TestChannelFactory())
             .setHost(host)
             .setProjectId(projectId)
             .setPrefetchChunks(2)
diff --git a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/it/ITDatabaseAdminTest.java b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/it/ITDatabaseAdminTest.java
index af76dc4a5288..04872090bb34 100644
--- a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/it/ITDatabaseAdminTest.java
+++ b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/it/ITDatabaseAdminTest.java
@@ -19,13 +19,13 @@
 import static com.google.cloud.spanner.SpannerMatchers.isSpannerException;
 import static com.google.common.truth.Truth.assertThat;
 
+import com.google.api.gax.longrunning.OperationFuture;
 import com.google.api.gax.paging.Page;
 import com.google.cloud.spanner.Database;
 import com.google.cloud.spanner.DatabaseAdminClient;
 import com.google.cloud.spanner.ErrorCode;
 import com.google.cloud.spanner.IntegrationTest;
 import com.google.cloud.spanner.IntegrationTestEnv;
-import com.google.cloud.spanner.Operation;
 import com.google.cloud.spanner.Options;
 import com.google.cloud.spanner.testing.RemoteSpannerHelper;
 import com.google.common.collect.ImmutableList;
@@ -74,10 +74,9 @@ public void databaseOperations() throws Exception {
     String dbId = testHelper.getUniqueDatabaseId();
     String instanceId = testHelper.getInstanceId().getInstance();
     String statement1 = "CREATE TABLE T (\n" + "  K STRING(MAX),\n" + ") PRIMARY KEY(K)";
-    Operation<Database, CreateDatabaseMetadata> op =
+    OperationFuture<Database, CreateDatabaseMetadata> op =
         dbAdminClient.createDatabase(instanceId, dbId, ImmutableList.of(statement1));
-    op = op.waitFor();
-    Database db = op.getResult();
+    Database db = op.get();
     dbs.add(db);
     assertThat(db.getId().getDatabase()).isEqualTo(dbId);
 
@@ -95,9 +94,9 @@ public void databaseOperations() throws Exception {
     assertThat(foundDb).isTrue();
 
     String statement2 = "CREATE TABLE T2 (\n" + "  K2 STRING(MAX),\n" + ") PRIMARY KEY(K2)";
-    Operation<?, ?> op2 =
+    OperationFuture<?, ?> op2 =
         dbAdminClient.updateDatabaseDdl(instanceId, dbId, ImmutableList.of(statement2), null);
-    op2.waitFor();
+    op2.get();
     List<String> statementsInDb = dbAdminClient.getDatabaseDdl(instanceId, dbId);
     assertThat(statementsInDb).containsExactly(statement1, statement2);
 
@@ -112,19 +111,18 @@ public void updateDdlRetry() throws Exception {
     String dbId = testHelper.getUniqueDatabaseId();
     String instanceId = testHelper.getInstanceId().getInstance();
     String statement1 = "CREATE TABLE T (\n" + "  K STRING(MAX),\n" + ") PRIMARY KEY(K)";
-    Operation<Database, CreateDatabaseMetadata> op =
+    OperationFuture<Database, CreateDatabaseMetadata> op =
         dbAdminClient.createDatabase(instanceId, dbId, ImmutableList.of(statement1));
-    op = op.waitFor();
-    Database db = op.getResult();
+    Database db = op.get();
     dbs.add(db);
     String statement2 = "CREATE TABLE T2 (\n" + "  K2 STRING(MAX),\n" + ") PRIMARY KEY(K2)";
-    Operation<Void, UpdateDatabaseDdlMetadata> op1 =
+    OperationFuture<Void, UpdateDatabaseDdlMetadata> op1 =
         dbAdminClient.updateDatabaseDdl(instanceId, dbId, ImmutableList.of(statement2), "myop");
-    Operation<Void, UpdateDatabaseDdlMetadata> op2 =
+    OperationFuture<Void, UpdateDatabaseDdlMetadata> op2 =
         dbAdminClient.updateDatabaseDdl(instanceId, dbId, ImmutableList.of(statement2), "myop");
-    op1 = op1.waitFor();
-    op2 = op2.waitFor();
-    assertThat(op1.getMetadata()).isEqualTo(op2.getMetadata());
+    op1.get();
+    op2.get();
+    assertThat(op1.getMetadata().get()).isEqualTo(op2.getMetadata().get());
   }
 
   @Test
@@ -132,10 +130,9 @@ public void databaseOperationsViaEntity() throws Exception {
     String dbId = testHelper.getUniqueDatabaseId();
     String instanceId = testHelper.getInstanceId().getInstance();
     String statement1 = "CREATE TABLE T (\n" + "  K STRING(MAX),\n" + ") PRIMARY KEY(K)";
-    Operation<Database, CreateDatabaseMetadata> op =
+    OperationFuture<Database, CreateDatabaseMetadata> op =
         dbAdminClient.createDatabase(instanceId, dbId, ImmutableList.of(statement1));
-    op = op.waitFor();
-    Database db = op.getResult();
+    Database db = op.get();
     dbs.add(db);
     assertThat(db.getId().getDatabase()).isEqualTo(dbId);
 
@@ -143,8 +140,8 @@ public void databaseOperationsViaEntity() throws Exception {
     assertThat(db.getId().getDatabase()).isEqualTo(dbId);
 
     String statement2 = "CREATE TABLE T2 (\n" + "  K2 STRING(MAX),\n" + ") PRIMARY KEY(K2)";
-    Operation<?, ?> op2 = db.updateDdl(ImmutableList.of(statement2), null);
-    op2.waitFor();
+    OperationFuture<?, ?> op2 = db.updateDdl(ImmutableList.of(statement2), null);
+    op2.get();
     Iterable<String> statementsInDb = db.getDdl();
     assertThat(statementsInDb).containsExactly(statement1, statement2);
 
@@ -164,9 +161,7 @@ public void listPagination() throws Exception {
 
     String instanceId = testHelper.getInstanceId().getInstance();
     for (String dbId : dbIds) {
-      dbs.add(dbAdminClient.createDatabase(instanceId, dbId, ImmutableList.<String>of())
-        .waitFor()
-        .getResult());
+      dbs.add(dbAdminClient.createDatabase(instanceId, dbId, ImmutableList.<String>of()).get());
     }
     Page<Database> page = dbAdminClient.listDatabases(instanceId, Options.pageSize(1));
     List<String> dbIdsGot = new ArrayList<>();
diff --git a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/it/ITInstanceAdminTest.java b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/it/ITInstanceAdminTest.java
index 57814da19bfe..494e80c4003b 100644
--- a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/it/ITInstanceAdminTest.java
+++ b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/it/ITInstanceAdminTest.java
@@ -18,13 +18,13 @@
 
 import static com.google.common.truth.Truth.assertThat;
 
+import com.google.api.gax.longrunning.OperationFuture;
 import com.google.cloud.spanner.Instance;
 import com.google.cloud.spanner.InstanceAdminClient;
 import com.google.cloud.spanner.InstanceConfig;
 import com.google.cloud.spanner.InstanceInfo;
 import com.google.cloud.spanner.IntegrationTest;
 import com.google.cloud.spanner.IntegrationTestEnv;
-import com.google.cloud.spanner.Operation;
 import com.google.cloud.spanner.Options;
 import com.google.common.collect.Iterators;
 import com.google.spanner.admin.instance.v1.UpdateInstanceMetadata;
@@ -90,9 +90,9 @@ public void updateInstance() throws Exception {
             .setNodeCount(instance.getNodeCount() + 1)
             .build();
     // Only update display name
-    Operation<Instance, UpdateInstanceMetadata> op =
+    OperationFuture<Instance, UpdateInstanceMetadata> op =
         instanceClient.updateInstance(toUpdate, InstanceInfo.InstanceField.DISPLAY_NAME);
-    Instance newInstance = op.waitFor().getResult();
+    Instance newInstance = op.get();
     assertThat(newInstance.getNodeCount()).isEqualTo(instance.getNodeCount());
     assertThat(newInstance.getDisplayName()).isEqualTo(newDisplayName);
 
@@ -102,7 +102,7 @@ public void updateInstance() throws Exception {
 
     toUpdate =
         InstanceInfo.newBuilder(instance.getId()).setDisplayName(instance.getDisplayName()).build();
-    instanceClient.updateInstance(toUpdate, InstanceInfo.InstanceField.DISPLAY_NAME).waitFor();
+    instanceClient.updateInstance(toUpdate, InstanceInfo.InstanceField.DISPLAY_NAME).get();
   }
 
   @Test
@@ -118,9 +118,9 @@ public void updateInstanceViaEntity() throws Exception {
             .setNodeCount(instance.getNodeCount() + 1)
             .build();
     // Only update display name
-    Operation<Instance, UpdateInstanceMetadata> op =
+    OperationFuture<Instance, UpdateInstanceMetadata> op =
         toUpdate.update(InstanceInfo.InstanceField.DISPLAY_NAME);
-    Instance newInstance = op.waitFor().getResult();
+    Instance newInstance = op.get();
     assertThat(newInstance.getNodeCount()).isEqualTo(instance.getNodeCount());
     assertThat(newInstance.getDisplayName()).isEqualTo(newDisplayName);
 
@@ -128,6 +128,6 @@ public void updateInstanceViaEntity() throws Exception {
     assertThat(newInstanceFromGet).isEqualTo(newInstance);
 
     toUpdate = newInstance.toBuilder().setDisplayName(instance.getDisplayName()).build();
-    toUpdate.update(InstanceInfo.InstanceField.DISPLAY_NAME).waitFor();
+    toUpdate.update(InstanceInfo.InstanceField.DISPLAY_NAME).get();
   }
 }
diff --git a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/spi/v1/RequestMetadataTest.java b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/spi/v1/RequestMetadataTest.java
deleted file mode 100644
index 3e27aa68e042..000000000000
--- a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/spi/v1/RequestMetadataTest.java
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * Copyright 2017 Google LLC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *       http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.google.cloud.spanner.spi.v1;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
-import static org.mockito.Mockito.doNothing;
-
-import com.google.cloud.spanner.spi.v1.GrpcSpannerRpc.MetadataClientCall;
-import io.grpc.ClientCall;
-import io.grpc.Metadata;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Captor;
-import org.mockito.Mock;
-import org.mockito.Mockito;
-import org.mockito.MockitoAnnotations;
-
-/** Unit tests for {@link GrpcSpannerRpc.MetadataClientCall}. */
-@RunWith(JUnit4.class)
-public class RequestMetadataTest {
-  private static final Metadata.Key<String> HEADER_KEY =
-      Metadata.Key.of("google-cloud-resource-prefix", Metadata.ASCII_STRING_MARSHALLER);
-
-  private Metadata metadata;
-
-  @Mock
-  private ClientCall<Void, Void> innerCall;
-  @Mock
-  private ClientCall.Listener<Void> listener;
-  @Captor
-  private ArgumentCaptor<Metadata> innerMetadata;
-
-  @Before
-  public void setUp() {
-    MockitoAnnotations.initMocks(this);
-    metadata = new Metadata();
-  }
-
-  @Test
-  public void metadataForwardingTest() {
-    doNothing()
-        .when(innerCall)
-        .start(Mockito.<ClientCall.Listener<Void>>any(), innerMetadata.capture());
-
-    Metadata in = new Metadata();
-    in.put(HEADER_KEY, "TEST_HEADER");
-    MetadataClientCall<Void, Void> metadataCall = new MetadataClientCall<>(innerCall, in);
-    metadataCall.start(listener, metadata);
-    assertTrue(innerMetadata.getValue().containsKey(HEADER_KEY));
-    assertEquals(innerMetadata.getValue().get(HEADER_KEY), "TEST_HEADER");
-  }
-}
diff --git a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/spi/v1/SpannerMetadataProviderTest.java b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/spi/v1/SpannerMetadataProviderTest.java
index 76f1f56c4d5a..12a9d2850ce4 100644
--- a/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/spi/v1/SpannerMetadataProviderTest.java
+++ b/google-cloud-clients/google-cloud-spanner/src/test/java/com/google/cloud/spanner/spi/v1/SpannerMetadataProviderTest.java
@@ -15,11 +15,14 @@
  */
 package com.google.cloud.spanner.spi.v1;
 
+import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assert.assertEquals;
 
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import io.grpc.Metadata;
 import io.grpc.Metadata.Key;
+import java.util.List;
 import java.util.Map;
 import org.junit.Test;
 
@@ -67,6 +70,16 @@ public void testGetResourceHeaderValue() {
         getResourceHeaderValue(metadataProvider, "projects/p/instances/i/databases/d/operations"));
   }
 
+  @Test
+  public void testNewExtraHeaders() {
+    SpannerMetadataProvider metadataProvider =
+        SpannerMetadataProvider.create(ImmutableMap.<String, String>of(), "header1");
+    Map<String, List<String>> extraHeaders = metadataProvider.newExtraHeaders(null, "value1");
+    assertThat(extraHeaders)
+        .containsExactlyEntriesIn(
+            ImmutableMap.<String, List<String>>of("header1", ImmutableList.<String>of("value1")));
+  }
+
   private String getResourceHeaderValue(
       SpannerMetadataProvider headerProvider, String resourceTokenTemplate) {
     Metadata metadata = headerProvider.newMetadata(resourceTokenTemplate, "projects/p");
diff --git a/google-cloud-examples/src/main/java/com/google/cloud/examples/spanner/snippets/DatabaseAdminClientSnippets.java b/google-cloud-examples/src/main/java/com/google/cloud/examples/spanner/snippets/DatabaseAdminClientSnippets.java
index 61c9baa6de7f..d0f5686ae89f 100644
--- a/google-cloud-examples/src/main/java/com/google/cloud/examples/spanner/snippets/DatabaseAdminClientSnippets.java
+++ b/google-cloud-examples/src/main/java/com/google/cloud/examples/spanner/snippets/DatabaseAdminClientSnippets.java
@@ -23,16 +23,19 @@
 package com.google.cloud.examples.spanner.snippets;
 
 import com.google.api.gax.paging.Page;
+import com.google.api.gax.longrunning.OperationFuture;
 import com.google.common.collect.Iterables;
 import com.google.cloud.spanner.DatabaseAdminClient;
 import com.google.cloud.spanner.Options;
 import com.google.cloud.spanner.Database;
-import com.google.cloud.spanner.Operation;
+import com.google.cloud.spanner.SpannerException;
+import com.google.cloud.spanner.SpannerExceptionFactory;
 import com.google.spanner.admin.database.v1.CreateDatabaseMetadata;
 
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.concurrent.ExecutionException;
 
 /**
  * This class contains snippets for {@link DatabaseAdminClient} interface.
@@ -53,7 +56,7 @@ public DatabaseAdminClientSnippets(DatabaseAdminClient dbAdminClient) {
   // [VARIABLE my_database_id]
   public Database createDatabase(String instanceId, String databaseId) {
     // [START createDatabase]
-    Operation<Database, CreateDatabaseMetadata> op = dbAdminClient
+    OperationFuture<Database, CreateDatabaseMetadata> op = dbAdminClient
         .createDatabase(
             instanceId,
             databaseId,
@@ -70,7 +73,14 @@ public Database createDatabase(String instanceId, String databaseId) {
                     + "  AlbumTitle   STRING(MAX)\n"
                     + ") PRIMARY KEY (SingerId, AlbumId),\n"
                     + "  INTERLEAVE IN PARENT Singers ON DELETE CASCADE"));
-    Database db = op.waitFor().getResult();
+    Database db;
+    try {
+      db = op.get();
+    } catch(ExecutionException e) {
+      throw (SpannerException) e.getCause();
+    } catch(InterruptedException e) {
+      throw SpannerExceptionFactory.propagateInterrupt(e);
+    }
     // [END createDatabase]
     return db;
   }
@@ -96,10 +106,16 @@ public Database getDatabase(String instanceId, String databaseId) {
   // [VARIABLE my_database_id]
   public void updateDatabaseDdl(String instanceId, String databaseId) {
     // [START updateDatabaseDdl]
-    dbAdminClient.updateDatabaseDdl(instanceId, 
+    try {
+      dbAdminClient.updateDatabaseDdl(instanceId, 
         databaseId, 
         Arrays.asList("ALTER TABLE Albums ADD COLUMN MarketingBudget INT64"), 
-        null).waitFor();
+        null).get();
+    } catch (ExecutionException e) {
+      throw (SpannerException) e.getCause();
+    } catch (InterruptedException e) {
+      throw SpannerExceptionFactory.propagateInterrupt(e);
+    }
     // [END updateDatabaseDdl]
   }
 
diff --git a/google-cloud-examples/src/main/java/com/google/cloud/examples/spanner/snippets/InstanceAdminClientSnippets.java b/google-cloud-examples/src/main/java/com/google/cloud/examples/spanner/snippets/InstanceAdminClientSnippets.java
index 501a28fc7280..02aa3e91b1a7 100644
--- a/google-cloud-examples/src/main/java/com/google/cloud/examples/spanner/snippets/InstanceAdminClientSnippets.java
+++ b/google-cloud-examples/src/main/java/com/google/cloud/examples/spanner/snippets/InstanceAdminClientSnippets.java
@@ -22,18 +22,21 @@
 
 package com.google.cloud.examples.spanner.snippets;
 
+import com.google.api.gax.longrunning.OperationFuture;
 import com.google.cloud.spanner.Instance;
 import com.google.cloud.spanner.InstanceAdminClient;
 import com.google.cloud.spanner.InstanceConfig;
 import com.google.cloud.spanner.InstanceConfigId;
 import com.google.cloud.spanner.InstanceId;
 import com.google.cloud.spanner.InstanceInfo;
-import com.google.cloud.spanner.Operation;
 import com.google.cloud.spanner.Options;
+import com.google.cloud.spanner.SpannerException;
+import com.google.cloud.spanner.SpannerExceptionFactory;
 import com.google.common.collect.Lists;
 import com.google.spanner.admin.instance.v1.CreateInstanceMetadata;
 import com.google.spanner.admin.instance.v1.UpdateInstanceMetadata;
 import java.util.List;
+import java.util.concurrent.ExecutionException;
 
 /**
  * This class contains snippets for {@link InstanceAdminClient} interface.
@@ -80,14 +83,20 @@ public void createInstance(
     final String configId = my_config_id;
     final String clientProject = my_client_project;
 
-    Operation<Instance, CreateInstanceMetadata> op =
+    OperationFuture<Instance, CreateInstanceMetadata> op =
         instanceAdminClient.createInstance(InstanceInfo
             .newBuilder(InstanceId.of(clientProject, instanceId))
             .setInstanceConfigId(InstanceConfigId.of(clientProject, configId))
             .setDisplayName(instanceId)
             .setNodeCount(1)
             .build());
-    op.waitFor();
+    try {
+      op.get();
+    } catch(ExecutionException e) {
+      throw (SpannerException) e.getCause();
+    } catch(InterruptedException e) {
+      throw SpannerExceptionFactory.propagateInterrupt(e);
+    }
     // [END instance_admin_client_create_instance]
   }
 
@@ -144,9 +153,15 @@ public void updateInstance(Instance my_instance,
             .setNodeCount(instance.getNodeCount() + 1)
             .build();
     // Only update display name
-    Operation<Instance, UpdateInstanceMetadata> op =
+    OperationFuture<Instance, UpdateInstanceMetadata> op =
         instanceAdminClient.updateInstance(toUpdate, InstanceInfo.InstanceField.DISPLAY_NAME);
-    op.waitFor().getResult();
+    try {
+      op.get();
+    } catch(ExecutionException e) {
+      throw (SpannerException) e.getCause();
+    } catch(InterruptedException e) {
+      throw SpannerExceptionFactory.propagateInterrupt(e);
+    }
     // [END instance_admin_client_update_instance]
   }
 }