Add bulkhead metrics support for Prometheus (ReactiveX#308)

resilience4j-prometheus/build.gradle

@@ -2,6 +2,8 @@ dependencies {
     compile (libraries.prometheus_simpleclient)
     compileOnly project(':resilience4j-circuitbreaker')
     compileOnly project(':resilience4j-ratelimiter')
+    compileOnly project(':resilience4j-bulkhead')
     testCompile project(':resilience4j-circuitbreaker')
     testCompile project(':resilience4j-ratelimiter')
+    testCompile project(':resilience4j-bulkhead')
 }

resilience4j-prometheus/src/main/java/io/github/resilience4j/prometheus/BulkheadExports.java

@@ -0,0 +1,220 @@
+/*
+ *
+ *  Copyright 2018 Valtteri Walldén
+ *
+ *  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.github.resilience4j.prometheus;
+
+import java.util.List;
+import java.util.function.Supplier;
+
+import io.github.resilience4j.bulkhead.Bulkhead;
+import io.github.resilience4j.bulkhead.BulkheadRegistry;
+import io.prometheus.client.Collector;
+import io.prometheus.client.GaugeMetricFamily;
+import io.vavr.collection.Array;
+
+import static java.util.Arrays.asList;
+import static java.util.Collections.singletonList;
+import static java.util.Objects.requireNonNull;
+
+/**
+ * An adapter from builtin {@link Bulkhead.Metrics} to prometheus
+ * {@link io.prometheus.client.CollectorRegistry}.
+ */
+public class BulkheadExports extends Collector {
+    private static final String DEFAULT_NAME = "resilience4j_bulkhead";
+
+    private final String                       name;
+    private final Supplier<Iterable<Bulkhead>> bulkheadsSupplier;
+
+    /**
+     * Creates a new instance of {@link BulkheadExports} with specified metrics names prefix and
+     * {@link Supplier} of bulkheads
+     *
+     * @param prefix the prefix of metrics names
+     * @param bulkheadSupplier the supplier of bulkheads
+     */
+    public static BulkheadExports ofSupplier(String prefix, Supplier<Iterable<Bulkhead>> bulkheadSupplier) {
+        return new BulkheadExports(prefix, bulkheadSupplier);
+    }
+
+    /**
+     * Creates a new instance of {@link BulkheadExports} with default metrics names prefix and
+     * {@link Supplier} of bulkheads
+     *
+     * @param bulkheadSupplier the supplier of bulkheads
+     */
+    public static BulkheadExports ofSupplier(Supplier<Iterable<Bulkhead>> bulkheadSupplier) {
+        return new BulkheadExports(DEFAULT_NAME, bulkheadSupplier);
+    }
+
+    /**
+     * Creates a new instance of {@link BulkheadExports} with default metrics names prefix and
+     * {@link BulkheadRegistry} as a source of bulkheads.
+
+     * @param bulkheadRegistry the registry of bulkheads
+     */
+    public static BulkheadExports ofBulkheadRegistry(BulkheadRegistry bulkheadRegistry) {
+        return new BulkheadExports(bulkheadRegistry.getAllBulkheads());
+    }
+
+    /**
+     * Creates a new instance of {@link BulkheadExports} with default metrics names prefix and
+     * a bulkhead as a source.
+     *
+     * @param bulkhead the bulkhead
+     */
+    public static BulkheadExports ofBulkhead(Bulkhead bulkhead) {
+        return new BulkheadExports(Array.of(bulkhead));
+    }
+
+
+    /**
+     * Creates a new instance of {@link BulkheadExports} with default metrics names prefix and
+     * {@link Iterable} of bulkheads.
+     *
+     * @param bulkheads the bulkheads
+     */
+    public static BulkheadExports ofIterable(Iterable<Bulkhead> bulkheads) {
+        return new BulkheadExports(bulkheads);
+    }
+
+    /**
+     * Creates a new instance of {@link BulkheadExports} with specified metrics names prefix and
+     * {@link BulkheadRegistry} as a source of bulkheads.
+     *
+     * @param prefix the prefix of metrics names
+     * @param bulkheadRegistry the registry of bulkheads
+     */
+    public static BulkheadExports ofBulkheadRegistry(String prefix, BulkheadRegistry bulkheadRegistry) {
+        return new BulkheadExports(prefix, bulkheadRegistry);
+    }
+
+    /**
+     * Creates a new instance of {@link BulkheadExports} with specified metrics names prefix and
+     * {@link Iterable} of bulkheads.
+     *
+     * @param prefix the prefix of metrics names
+     * @param bulkheads the bulkheads
+     */
+    public static BulkheadExports ofIterable(String prefix, Iterable<Bulkhead> bulkheads) {
+        return new BulkheadExports(prefix, bulkheads);
+    }
+
+
+    /**
+     * Creates a new instance of {@link BulkheadExports} with default metrics names prefix and
+     * a bulkhead as a source.
+     *
+     * @param prefix the prefix of metrics names
+     * @param bulkhead the bulkhead
+     */
+    public static BulkheadExports ofBulkhead(String prefix, Bulkhead bulkhead) {
+        return new BulkheadExports(prefix, Array.of(bulkhead));
+    }
+
+
+    /**
+     * Creates a new instance of {@link BulkheadExports} with default metric name and
+     * {@link BulkheadRegistry}.
+     *
+     * @param bulkheadRegistry the bulkhead registry
+     */
+    private BulkheadExports(BulkheadRegistry bulkheadRegistry) {
+        this(bulkheadRegistry::getAllBulkheads);
+    }
+
+    /**
+     * Creates a new instance of {@link BulkheadExports} with default metric name and
+     * {@link Iterable} of bulkheads.
+     *
+     * @param bulkheads the bulkheads
+     */
+    private BulkheadExports(Iterable<Bulkhead> bulkheads) {
+        this(() -> bulkheads);
+    }
+
+    /**
+     * Creates a new instance of {@link BulkheadExports} with default metric name and
+     * {@link Supplier} of bulkheads
+     *
+     * @param bulkheadsSupplier the supplier of bulkheads
+     */
+    private BulkheadExports(Supplier<Iterable<Bulkhead>> bulkheadsSupplier) {
+        this(DEFAULT_NAME, bulkheadsSupplier);
+    }
+
+    /**
+     * Creates a new instance of {@link BulkheadExports} with specified metric name and
+     * {@link BulkheadRegistry}.
+     *
+     * @param name the name of metric
+     * @param bulkheadRegistry the bulkhead registry
+     */
+    public BulkheadExports(String name, BulkheadRegistry bulkheadRegistry) {
+        this(name, bulkheadRegistry::getAllBulkheads);
+    }
+
+
+    /**
+     * Creates a new instance of {@link BulkheadExports} with specified metric name and
+     * {@link Iterable} of bulkheads.
+     *
+     * @param name the name of metric
+     * @param bulkheads the bulkheads
+     */
+    private BulkheadExports(String name, Iterable<Bulkhead> bulkheads) {
+        this(name, () -> bulkheads);
+    }
+
+    /**
+     * Creates a new instance of {@link BulkheadExports} with specified metric name and
+     * {@link Supplier} of bulkheads
+     *
+     * @param name the name of metric
+     * @param bulkheadsSupplier the supplier of bulkheads
+     */
+    private BulkheadExports(String name, Supplier<Iterable<Bulkhead>> bulkheadsSupplier) {
+        requireNonNull(name);
+        requireNonNull(bulkheadsSupplier);
+
+        this.name = name;
+        this.bulkheadsSupplier = bulkheadsSupplier;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public List<MetricFamilySamples> collect() {
+        final GaugeMetricFamily stats = new GaugeMetricFamily(
+                name,
+                "Bulkhead Stats",
+                asList("name", "param"));
+
+        for (Bulkhead bulkhead : bulkheadsSupplier.get()) {
+
+            final Bulkhead.Metrics metrics = bulkhead.getMetrics();
+
+            stats.addMetric(
+                    asList(bulkhead.getName(), "available_concurrent_calls"),
+                    metrics.getAvailableConcurrentCalls());
+        }
+
+        return singletonList(stats);
+    }
+}

resilience4j-prometheus/src/main/java/io/github/resilience4j/prometheus/RateLimiterExports.java

@@ -71,25 +71,26 @@ public static RateLimiterExports ofSupplier(Supplier<Iterable<RateLimiter>> rate
     public static RateLimiterExports ofRateLimiterRegistry(RateLimiterRegistry rateLimiterRegistry) {
         return new RateLimiterExports(rateLimiterRegistry.getAllRateLimiters());
     }
+
     /**
      * Creates a new instance of {@link RateLimiterExports} with default metrics names prefix and
-     * a circuit breaker as a source.
+     * a rate limiter as a source.
      *
-     * @param RateLimiter the rate limiter
+     * @param rateLimiter the rate limiter
      */
-    public static RateLimiterExports ofRateLimiter(RateLimiter RateLimiter) {
-        return new RateLimiterExports(Array.of(RateLimiter));
+    public static RateLimiterExports ofRateLimiter(RateLimiter rateLimiter) {
+        return new RateLimiterExports(Array.of(rateLimiter));
     }
 
 
     /**
      * Creates a new instance of {@link RateLimiterExports} with default metrics names prefix and
      * {@link Iterable} of rate limiters.
      *
-     * @param RateLimiters the rate limiters
+     * @param rateLimiters the rate limiters
      */
-    public static RateLimiterExports ofIterable(Iterable<RateLimiter> RateLimiters) {
-        return new RateLimiterExports(RateLimiters);
+    public static RateLimiterExports ofIterable(Iterable<RateLimiter> rateLimiters) {
+        return new RateLimiterExports(rateLimiters);
     }
 
     /**
@@ -108,21 +109,21 @@ public static RateLimiterExports ofRateLimiterRegistry(String prefix, RateLimite
      * {@link Iterable} of rate limiters.
      *
      * @param prefix the prefix of metrics names
-     * @param rateLimiter the rate limiters
+     * @param rateLimiters the rate limiters
      */
-    public static RateLimiterExports ofIterable(String prefix, Iterable<RateLimiter> rateLimiter) {
-        return new RateLimiterExports(prefix, rateLimiter);
+    public static RateLimiterExports ofIterable(String prefix, Iterable<RateLimiter> rateLimiters) {
+        return new RateLimiterExports(prefix, rateLimiters);
     }
 
     /**
      * Creates a new instance of {@link RateLimiterExports} with default metrics names prefix and
-     * a circuit breaker as a source.
+     * a rate limiter as a source.
      *
      * @param prefix the prefix of metrics names
-     * @param RateLimiter the circuit breaker
+     * @param rateLimiter the rate limiter
      */
-    public static RateLimiterExports ofRateLimiter(String prefix, RateLimiter RateLimiter) {
-        return new RateLimiterExports(prefix, Array.of(RateLimiter));
+    public static RateLimiterExports ofRateLimiter(String prefix, RateLimiter rateLimiter) {
+        return new RateLimiterExports(prefix, Array.of(rateLimiter));
     }
 
     /**

resilience4j-prometheus/src/test/java/io/github/resilience4j/prometheus/BulkheadExportsTest.java

@@ -0,0 +1,88 @@
+/*
+ *
+ *  Copyright 2018 Valtteri Walldén
+ *
+ *  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.github.resilience4j.prometheus;
+
+import org.junit.Test;
+
+import java.util.function.Supplier;
+
+import io.github.resilience4j.bulkhead.Bulkhead;
+import io.github.resilience4j.bulkhead.BulkheadConfig;
+import io.github.resilience4j.bulkhead.BulkheadRegistry;
+import io.github.resilience4j.bulkhead.internal.InMemoryBulkheadRegistry;
+import io.prometheus.client.CollectorRegistry;
+import io.vavr.Tuple;
+import io.vavr.collection.HashMap;
+import io.vavr.collection.HashSet;
+import io.vavr.collection.Map;
+
+import static java.util.Collections.singleton;
+import static java.util.Collections.singletonList;
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class BulkheadExportsTest {
+
+  @Test
+  public void testExportsCircuitBreakerStates() {
+      // Given
+      final CollectorRegistry registry = new CollectorRegistry();
+
+      final Bulkhead bulkhead = Bulkhead.ofDefaults("foo");
+
+      BulkheadExports.ofIterable("boo_bulkhead", singletonList(bulkhead)).register(registry);
+
+      final Supplier<Map<String, Double>> values = () -> HashSet
+              .of("available_concurrent_calls")
+              .map(param ->
+                      Tuple.of(param, registry.getSampleValue(
+                              "boo_bulkhead",
+                              new String[]{"name", "param"},
+                              new String[]{"foo", param})))
+              .toMap(t -> t);
+
+      // When
+      final Map<String, Double> initialValues = values.get();
+
+      // Then
+      assertThat(initialValues).isEqualTo(HashMap.of("available_concurrent_calls", 25.0));
+  }
+
+    @Test
+    public void testConstructors() {
+        final BulkheadRegistry registry = new InMemoryBulkheadRegistry(BulkheadConfig.ofDefaults());
+
+        BulkheadExports.ofIterable("boo_bulkheads", singleton(Bulkhead.ofDefaults("foo")));
+        BulkheadExports.ofBulkheadRegistry("boo_bulkheads", registry);
+        BulkheadExports.ofSupplier("boo_bulkheads", () -> singleton(Bulkhead.ofDefaults("foo")));
+
+        BulkheadExports.ofIterable(singleton(Bulkhead.ofDefaults("foo")));
+        BulkheadExports.ofBulkheadRegistry(registry);
+        BulkheadExports.ofSupplier(() -> singleton(Bulkhead.ofDefaults("foo")));
+    }
+
+    @Test(expected = NullPointerException.class)
+    public void testConstructorWithNullName() {
+        BulkheadExports.ofSupplier(null, () -> singleton(Bulkhead.ofDefaults("foo")));
+    }
+
+    @Test(expected = NullPointerException.class)
+    public void testConstructorWithNullSupplier() {
+        BulkheadExports.ofSupplier("boo_bulkheads", null);
+    }
+}