Add the KPI metrics handler (with no qualifying path) exactly once to…

… each routing (#3255) (#3282)

microprofile/metrics/pom.xml

@@ -94,6 +94,8 @@
                         <configuration>
                             <excludes>
                                 <exclude>**/HelloWorldAsyncResponseTest.java</exclude>
+                                <exclude>**/TestExtendedKPIMetrics.java</exclude>
+                                <exclude>**/TestMetricsOnOwnSocket.java</exclude>
                             </excludes>
                         </configuration>
                     </execution>
@@ -106,6 +108,8 @@
                         <configuration>
                             <includes>
                                 <include>**/HelloWorldAsyncResponseTest.java</include>
+                                <include>**/TestExtendedKPIMetrics.java</include>
+                                <include>**/TestMetricsOnOwnSocket.java</include>
                             </includes>
                         </configuration>
                     </execution>

microprofile/metrics/src/test/java/io/helidon/microprofile/metrics/HelloWorldApp.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2021 Oracle and/or its affiliates.
+ *
+ * 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 io.helidon.microprofile.metrics;
+
+import javax.enterprise.context.ApplicationScoped;
+import javax.ws.rs.ApplicationPath;
+import javax.ws.rs.core.Application;
+import java.util.Set;
+
+@ApplicationScoped
+@ApplicationPath("/")
+public class HelloWorldApp extends Application {
+
+    @Override
+    public Set<Class<?>> getClasses() {
+        return Set.of(HelloWorldResource.class);
+    }
+}

microprofile/metrics/src/test/java/io/helidon/microprofile/metrics/TestExtendedKPIMetrics.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2021 Oracle and/or its affiliates.
+ *
+ * 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 io.helidon.microprofile.metrics;
+
+import io.helidon.common.http.Http;
+import io.helidon.microprofile.tests.junit5.AddBean;
+import io.helidon.microprofile.tests.junit5.AddConfig;
+import io.helidon.microprofile.tests.junit5.HelidonTest;
+import org.junit.jupiter.api.Test;
+
+import javax.inject.Inject;
+import javax.json.JsonObject;
+import javax.ws.rs.client.WebTarget;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+
+import static io.helidon.metrics.KeyPerformanceIndicatorMetricsSettings.Builder.KEY_PERFORMANCE_INDICATORS_CONFIG_KEY;
+import static io.helidon.metrics.KeyPerformanceIndicatorMetricsSettings.Builder.KEY_PERFORMANCE_INDICATORS_EXTENDED_CONFIG_KEY;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.greaterThan;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.notNullValue;
+
+@HelidonTest
+@AddConfig(key =
+        "metrics."
+                + KEY_PERFORMANCE_INDICATORS_CONFIG_KEY
+                + "." + KEY_PERFORMANCE_INDICATORS_EXTENDED_CONFIG_KEY,
+        value = "true")
+@AddConfig(key = "server.executor-service.core-pool-size", value = "1")
+@AddConfig(key = "server.executor-service.max-pool-size", value = "1")
+@AddBean(HelloWorldApp.class)
+public class TestExtendedKPIMetrics {
+
+    @Inject
+    WebTarget webTarget;
+
+
+    @Test
+    void checkNonZeroDeferredTime() throws ExecutionException, InterruptedException {
+        // Run two requests concurrently, with the server configured for one thread, to force one request to be deferred.
+        Future<Response> response1Future = webTarget
+                .path("helloworld")
+                .request()
+                .accept(MediaType.TEXT_PLAIN)
+                .buildGet()
+                .submit();
+
+        Future<Response> response2Future = webTarget
+                .path("helloworld")
+                .request()
+                .accept(MediaType.TEXT_PLAIN)
+                .buildGet()
+                .submit();
+
+        // Now wait for both requests to finish.
+        try (Response response1 = response1Future.get(); Response response2 = response2Future.get()) {
+            assertThat("Access to GET response 1", response1.getStatus(), is(Http.Status.OK_200.code()));
+            assertThat("Access to GET response 2", response2.getStatus(), is(Http.Status.OK_200.code()));
+        }
+
+        try (Response metricsResponse = webTarget
+                .path("metrics/vendor")
+                .request()
+                .accept(MediaType.APPLICATION_JSON_TYPE)
+                .get()) {
+
+            assertThat("Metrics /metrics/vendor URL HTTP status", metricsResponse.getStatus(), is(Http.Status.OK_200.code()));
+
+            JsonObject vendorMetrics = metricsResponse.readEntity(JsonObject.class);
+
+            assertThat("Extended KPI metric requests.deferred present", vendorMetrics.containsKey("requests.deferred"),
+                    is(true));
+
+            JsonObject requestsDeferred = vendorMetrics.getJsonObject("requests.deferred");
+            assertThat("requests.deferred", requestsDeferred, is(notNullValue()));
+
+            int deferredCount = requestsDeferred.getInt("count");
+            assertThat("Extended KPI metric requests.deferred->count value", deferredCount, is(greaterThan(0)));
+        }
+    }
+}

microprofile/server/src/main/java/io/helidon/microprofile/server/ServerCdiExtension.java

@@ -23,6 +23,7 @@
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.IdentityHashMap;
 import java.util.LinkedList;
 import java.util.List;
@@ -103,6 +104,8 @@ public class ServerCdiExtension implements Extension {
     private final Map<Bean<?>, RoutingConfiguration> serviceBeans
             = Collections.synchronizedMap(new IdentityHashMap<>());
 
+    private final Set<Routing.Builder> routingsWithKPIMetrics = new HashSet<>();
+
     private void buildTime(@Observes @BuildTimeStart Object event) {
         // update the status of server, as we may have been started without a builder being used
         // such as when cdi.Main or SeContainerInitializer are used
@@ -146,19 +149,16 @@ private void recordBeanServices(@Observes ProcessManagedBean<? extends Service>
 
     private void registerKpiMetricsDeferrableRequestContextSetterHandler(JaxRsCdiExtension jaxRs,
             JaxRsApplication applicationMeta) {
-        Optional<String> contextRoot = jaxRs.findContextRoot(config, applicationMeta);
         Optional<String> namedRouting = jaxRs.findNamedRouting(config, applicationMeta);
         boolean routingNameRequired = jaxRs.isNamedRoutingRequired(config, applicationMeta);
 
         Routing.Builder routing = routingBuilder(namedRouting, routingNameRequired, applicationMeta.appName());
 
-        if (contextRoot.isPresent()) {
-            String contextRootString = contextRoot.get();
-            routing.any(contextRootString, KeyPerformanceIndicatorSupport.DeferrableRequestContext.CONTEXT_SETTING_HANDLER);
-        } else {
-            LOGGER.finer(() ->
-                    "JAX-RS application " + applicationMeta.appName() + " adding deferrable request KPI metrics context on '/'");
+        if (!routingsWithKPIMetrics.contains(routing)) {
+            routingsWithKPIMetrics.add(routing);
             routing.any(KeyPerformanceIndicatorSupport.DeferrableRequestContext.CONTEXT_SETTING_HANDLER);
+            LOGGER.finer(() -> String.format("Adding deferrable request KPI metrics context for routing with name '%s'",
+                            namedRouting.orElse("<unnamed>")));
         }
     }