Add R2BC connection pool metrics

This commit adds metrics support for `ConnectionPool` beans.

See gh-19988

Co-authored-by: Mark Paluch <mpaluch@pivotal.io>
Co-authored-by: Tadaya Tsuyukubo <tadaya@ttddyy.net>

spring-boot-project/spring-boot-actuator-autoconfigure/build.gradle

@@ -61,6 +61,7 @@ dependencies {
 	optional("io.micrometer:micrometer-registry-statsd")
 	optional("io.micrometer:micrometer-registry-wavefront")
 	optional("io.projectreactor.netty:reactor-netty")
+	optional("io.r2dbc:r2dbc-pool")
 	optional("io.r2dbc:r2dbc-spi")
 	optional("jakarta.jms:jakarta.jms-api")
 	optional("jakarta.servlet:jakarta.servlet-api")

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/r2dbc/ConnectionPoolMetricsAutoConfiguration.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2012-2020 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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 org.springframework.boot.actuate.autoconfigure.metrics.r2dbc;
+
+import java.util.Map;
+
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.Tags;
+import io.r2dbc.pool.ConnectionPool;
+import io.r2dbc.spi.ConnectionFactory;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.actuate.autoconfigure.metrics.MetricsAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.metrics.export.simple.SimpleMetricsExportAutoConfiguration;
+import org.springframework.boot.actuate.metrics.r2dbc.ConnectionPoolMetrics;
+import org.springframework.boot.autoconfigure.AutoConfigureAfter;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.r2dbc.R2dbcAutoConfiguration;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * {@link EnableAutoConfiguration Auto-configuration} for metrics on all available
+ * {@link ConnectionFactory R2DBC connection factories}.
+ *
+ * @author Tadaya Tsuyukubo
+ * @author Stephane Nicoll
+ * @since 2.3.0
+ */
+@Configuration(proxyBeanMethods = false)
+@AutoConfigureAfter({ MetricsAutoConfiguration.class, SimpleMetricsExportAutoConfiguration.class,
+		R2dbcAutoConfiguration.class })
+@ConditionalOnClass({ ConnectionPool.class, MeterRegistry.class })
+@ConditionalOnBean({ ConnectionPool.class, MeterRegistry.class })
+public class ConnectionPoolMetricsAutoConfiguration {
+
+	@Autowired
+	public void bindConnectionPoolsToRegistry(Map<String, ConnectionPool> connectionPools, MeterRegistry registry) {
+		connectionPools.forEach((beanName,
+				connectionPool) -> new ConnectionPoolMetrics(connectionPool, beanName, Tags.empty()).bindTo(registry));
+	}
+
+}

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/r2dbc/package-info.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2012-2020 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.
+ */
+
+/**
+ * Auto-configuration for R2DBC metrics.
+ */
+package org.springframework.boot.actuate.autoconfigure.metrics.r2dbc;

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/resources/META-INF/spring.factories

@@ -67,6 +67,7 @@ org.springframework.boot.actuate.autoconfigure.metrics.export.wavefront.Wavefron
 org.springframework.boot.actuate.autoconfigure.metrics.jdbc.DataSourcePoolMetricsAutoConfiguration,\
 org.springframework.boot.actuate.autoconfigure.metrics.jersey.JerseyServerMetricsAutoConfiguration,\
 org.springframework.boot.actuate.autoconfigure.metrics.orm.jpa.HibernateMetricsAutoConfiguration,\
+org.springframework.boot.actuate.autoconfigure.metrics.r2dbc.ConnectionPoolMetricsAutoConfiguration,\
 org.springframework.boot.actuate.autoconfigure.metrics.web.client.HttpClientMetricsAutoConfiguration,\
 org.springframework.boot.actuate.autoconfigure.metrics.web.jetty.JettyMetricsAutoConfiguration,\
 org.springframework.boot.actuate.autoconfigure.metrics.web.reactive.WebFluxMetricsAutoConfiguration,\

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/r2dbc/ConnectionPoolMetricsAutoConfigurationTests.java

@@ -0,0 +1,112 @@
+/*
+ * Copyright 2012-2020 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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 org.springframework.boot.actuate.autoconfigure.metrics.r2dbc;
+
+import java.util.Collections;
+import java.util.UUID;
+
+import io.micrometer.core.instrument.Meter;
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
+import io.r2dbc.h2.CloseableConnectionFactory;
+import io.r2dbc.h2.H2ConnectionFactory;
+import io.r2dbc.h2.H2ConnectionOption;
+import io.r2dbc.pool.ConnectionPool;
+import io.r2dbc.pool.ConnectionPoolConfiguration;
+import io.r2dbc.spi.ConnectionFactory;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.actuate.autoconfigure.metrics.test.MetricsRun;
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.autoconfigure.r2dbc.R2dbcAutoConfiguration;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link ConnectionPoolMetricsAutoConfiguration}.
+ *
+ * @author Tadaya Tsuyukubo
+ * @author Stephane Nicoll
+ */
+class ConnectionPoolMetricsAutoConfigurationTests {
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+			.withPropertyValues("spring.r2dbc.generate-unique-name=true").with(MetricsRun.simple())
+			.withConfiguration(AutoConfigurations.of(ConnectionPoolMetricsAutoConfiguration.class))
+			.withUserConfiguration(BaseConfiguration.class);
+
+	@Test
+	void autoConfiguredDataSourceIsInstrumented() {
+		this.contextRunner.withConfiguration(AutoConfigurations.of(R2dbcAutoConfiguration.class)).run((context) -> {
+			MeterRegistry registry = context.getBean(MeterRegistry.class);
+			assertThat(registry.find("r2dbc.pool.acquired").gauges()).hasSize(1);
+		});
+	}
+
+	@Test
+	void connectionPoolInstrumentationCanBeDisabled() {
+		this.contextRunner.withConfiguration(AutoConfigurations.of(R2dbcAutoConfiguration.class))
+				.withPropertyValues("management.metrics.enable.r2dbc=false").run((context) -> {
+					MeterRegistry registry = context.getBean(MeterRegistry.class);
+					assertThat(registry.find("r2dbc.pool.acquired").gauge()).isNull();
+				});
+	}
+
+	@Test
+	void allConnectionPoolsCanBeInstrumented() {
+		this.contextRunner.withUserConfiguration(TwoConnectionPoolsConfiguration.class).run((context) -> {
+			MeterRegistry registry = context.getBean(MeterRegistry.class);
+			assertThat(registry.find("r2dbc.pool.acquired").gauges()).extracting(Meter::getId)
+					.extracting((id) -> id.getTag("name")).containsExactlyInAnyOrder("firstPool", "secondPool");
+		});
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class BaseConfiguration {
+
+		@Bean
+		SimpleMeterRegistry registry() {
+			return new SimpleMeterRegistry();
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class TwoConnectionPoolsConfiguration {
+
+		@Bean
+		CloseableConnectionFactory connectionFactory() {
+			return H2ConnectionFactory.inMemory("db-" + UUID.randomUUID(), "sa", "",
+					Collections.singletonMap(H2ConnectionOption.DB_CLOSE_DELAY, "-1"));
+		}
+
+		@Bean
+		ConnectionPool firstPool(ConnectionFactory connectionFactory) {
+			return new ConnectionPool(ConnectionPoolConfiguration.builder(connectionFactory).build());
+		}
+
+		@Bean
+		ConnectionPool secondPool(ConnectionFactory connectionFactory) {
+			return new ConnectionPool(ConnectionPoolConfiguration.builder(connectionFactory).build());
+		}
+
+	}
+
+}

spring-boot-project/spring-boot-actuator/build.gradle

@@ -24,6 +24,7 @@ dependencies {
 	optional("io.micrometer:micrometer-core")
 	optional("io.micrometer:micrometer-registry-prometheus")
 	optional("io.prometheus:simpleclient_pushgateway")
+	optional("io.r2dbc:r2dbc-pool")
 	optional("io.r2dbc:r2dbc-spi")
 	optional("io.reactivex:rxjava-reactive-streams")
 	optional("org.elasticsearch.client:elasticsearch-rest-client")

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/r2dbc/ConnectionPoolMetrics.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2012-2020 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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 org.springframework.boot.actuate.metrics.r2dbc;
+
+import io.micrometer.core.instrument.Gauge;
+import io.micrometer.core.instrument.Gauge.Builder;
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.Tag;
+import io.micrometer.core.instrument.Tags;
+import io.micrometer.core.instrument.binder.MeterBinder;
+import io.r2dbc.pool.ConnectionPool;
+import io.r2dbc.pool.PoolMetrics;
+
+/**
+ * A {@link MeterBinder} for a {@link ConnectionPool}.
+ *
+ * @author Tadaya Tsuyukubo
+ * @author Stephane Nicoll
+ * @since 2.3.0
+ */
+public class ConnectionPoolMetrics implements MeterBinder {
+
+	private static final String CONNECTIONS = "connections";
+
+	private final ConnectionPool pool;
+
+	private final Iterable<Tag> tags;
+
+	public ConnectionPoolMetrics(ConnectionPool pool, String name, Iterable<Tag> tags) {
+		this.pool = pool;
+		this.tags = Tags.concat(tags, "name", name);
+	}
+
+	@Override
+	public void bindTo(MeterRegistry registry) {
+		this.pool.getMetrics().ifPresent((poolMetrics) -> {
+			bindConnectionPoolMetric(registry,
+					Gauge.builder(metricKey("acquired"), poolMetrics, PoolMetrics::acquiredSize)
+							.description("Size of successfully acquired connections which are in active use."));
+			bindConnectionPoolMetric(registry,
+					Gauge.builder(metricKey("allocated"), poolMetrics, PoolMetrics::allocatedSize)
+							.description("Size of allocated connections in the pool which are in active use or idle."));
+			bindConnectionPoolMetric(registry, Gauge.builder(metricKey("idle"), poolMetrics, PoolMetrics::idleSize)
+					.description("Size of idle connections in the pool."));
+			bindConnectionPoolMetric(registry,
+					Gauge.builder(metricKey("pending"), poolMetrics, PoolMetrics::pendingAcquireSize).description(
+							"Size of pending to acquire connections from the underlying connection factory."));
+			bindConnectionPoolMetric(registry,
+					Gauge.builder(metricKey("max.allocated"), poolMetrics, PoolMetrics::getMaxAllocatedSize)
+							.description("Maximum size of allocated connections that this pool allows."));
+			bindConnectionPoolMetric(registry,
+					Gauge.builder(metricKey("max.pending"), poolMetrics, PoolMetrics::getMaxPendingAcquireSize)
+							.description(
+									"Maximum size of pending state to acquire connections that this pool allows."));
+		});
+	}
+
+	private void bindConnectionPoolMetric(MeterRegistry registry, Builder<?> builder) {
+		builder.tags(this.tags).baseUnit(CONNECTIONS).register(registry);
+	}
+
+	private static String metricKey(String name) {
+		return "r2dbc.pool." + name;
+	}
+
+}

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/r2dbc/package-info.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2012-2020 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.
+ */
+
+/**
+ * Actuator support for R2DBC metrics.
+ */
+package org.springframework.boot.actuate.metrics.r2dbc;

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/r2dbc/ConnectionPoolMetricsTests.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright 2012-2020 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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 org.springframework.boot.actuate.metrics.r2dbc;
+
+import java.util.Collections;
+import java.util.UUID;
+
+import io.micrometer.core.instrument.Gauge;
+import io.micrometer.core.instrument.Tag;
+import io.micrometer.core.instrument.Tags;
+import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
+import io.r2dbc.h2.CloseableConnectionFactory;
+import io.r2dbc.h2.H2ConnectionFactory;
+import io.r2dbc.h2.H2ConnectionOption;
+import io.r2dbc.pool.ConnectionPool;
+import io.r2dbc.pool.ConnectionPoolConfiguration;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import reactor.test.StepVerifier;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link ConnectionPoolMetrics}.
+ *
+ * @author Tadaya Tsuyukubo
+ * @author Mark Paluch
+ * @author Stephane Nicoll
+ */
+class ConnectionPoolMetricsTests {
+
+	private static final Tag testTag = Tag.of("test", "yes");
+
+	private static final Tag regionTag = Tag.of("region", "eu-2");
+
+	private CloseableConnectionFactory connectionFactory;
+
+	@BeforeEach
+	void init() {
+		this.connectionFactory = H2ConnectionFactory.inMemory("db-" + UUID.randomUUID(), "sa", "",
+				Collections.singletonMap(H2ConnectionOption.DB_CLOSE_DELAY, "-1"));
+	}
+
+	@AfterEach
+	void close() {
+		if (this.connectionFactory != null) {
+			this.connectionFactory.close();
+		}
+	}
+
+	@Test
+	void connectionFactoryIsInstrumented() {
+		SimpleMeterRegistry registry = new SimpleMeterRegistry();
+		ConnectionPool connectionPool = new ConnectionPool(
+				ConnectionPoolConfiguration.builder(this.connectionFactory).initialSize(3).maxSize(7).build());
+		ConnectionPoolMetrics metrics = new ConnectionPoolMetrics(connectionPool, "test-pool",
+				Tags.of(testTag, regionTag));
+		metrics.bindTo(registry);
+		// acquire two connections
+		connectionPool.create().as(StepVerifier::create).expectNextCount(1).verifyComplete();
+		connectionPool.create().as(StepVerifier::create).expectNextCount(1).verifyComplete();
+		assertGauge(registry, "r2dbc.pool.acquired", 2);
+		assertGauge(registry, "r2dbc.pool.allocated", 3);
+		assertGauge(registry, "r2dbc.pool.idle", 1);
+		assertGauge(registry, "r2dbc.pool.pending", 0);
+		assertGauge(registry, "r2dbc.pool.max.allocated", 7);
+		assertGauge(registry, "r2dbc.pool.max.pending", Integer.MAX_VALUE);
+	}
+
+	private void assertGauge(SimpleMeterRegistry registry, String metric, int expectedValue) {
+		Gauge gauge = registry.get(metric).gauge();
+		assertThat(gauge.value()).isEqualTo(expectedValue);
+		assertThat(gauge.getId().getTags()).containsExactlyInAnyOrder(Tag.of("name", "test-pool"), testTag, regionTag);
+	}
+
+}