Expose cache metrics for Redis

This commit adds support for Redis cache metrics. Users can opt-in for
statistics using the "spring.cache.redis.enable-statistics" property.

Closes gh-22701

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/cache/CacheMeterBinderProvidersConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * 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.
@@ -26,12 +26,14 @@ import org.springframework.boot.actuate.metrics.cache.CaffeineCacheMeterBinderPr
 import org.springframework.boot.actuate.metrics.cache.EhCache2CacheMeterBinderProvider;
 import org.springframework.boot.actuate.metrics.cache.HazelcastCacheMeterBinderProvider;
 import org.springframework.boot.actuate.metrics.cache.JCacheCacheMeterBinderProvider;
+import org.springframework.boot.actuate.metrics.cache.RedisCacheMeterBinderProvider;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.cache.caffeine.CaffeineCache;
 import org.springframework.cache.ehcache.EhCacheCache;
 import org.springframework.cache.jcache.JCacheCache;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.data.redis.cache.RedisCache;
 
 /**
  * Configure {@link CacheMeterBinderProvider} beans.
@@ -86,4 +88,15 @@ class CacheMeterBinderProvidersConfiguration {
 
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnClass(RedisCache.class)
+	static class RedisCacheMeterBinderProviderConfiguration {
+
+		@Bean
+		RedisCacheMeterBinderProvider redisCacheMeterBinderProvider() {
+			return new RedisCacheMeterBinderProvider();
+		}
+
+	}
+
 }

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

@@ -83,6 +83,7 @@ dependencies {
 	testImplementation("org.skyscreamer:jsonassert")
 	testImplementation("org.springframework:spring-test")
 	testImplementation("com.squareup.okhttp3:mockwebserver")
+	testImplementation("org.testcontainers:junit-jupiter")
 
 	testRuntimeOnly("io.projectreactor.netty:reactor-netty-http")
 	testRuntimeOnly("javax.xml.bind:jaxb-api")

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/cache/RedisCacheMeterBinderProvider.java

@@ -0,0 +1,37 @@
+/*
+ * 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.cache;
+
+import io.micrometer.core.instrument.Tag;
+import io.micrometer.core.instrument.binder.MeterBinder;
+
+import org.springframework.data.redis.cache.RedisCache;
+
+/**
+ * {@link CacheMeterBinderProvider} implementation for Redis.
+ *
+ * @author Stephane Nicoll
+ * @since 2.4.0
+ */
+public class RedisCacheMeterBinderProvider implements CacheMeterBinderProvider<RedisCache> {
+
+	@Override
+	public MeterBinder getMeterBinder(RedisCache cache, Iterable<Tag> tags) {
+		return new RedisCacheMetrics(cache, tags);
+	}
+
+}

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/cache/RedisCacheMetrics.java

@@ -0,0 +1,83 @@
+/*
+ * 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.cache;
+
+import java.util.concurrent.TimeUnit;
+
+import io.micrometer.core.instrument.FunctionCounter;
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.Tag;
+import io.micrometer.core.instrument.TimeGauge;
+import io.micrometer.core.instrument.binder.cache.CacheMeterBinder;
+
+import org.springframework.data.redis.cache.RedisCache;
+
+/**
+ * {@link CacheMeterBinder} for {@link RedisCache}.
+ *
+ * @author Stephane Nicoll
+ * @since 2.4.0
+ */
+public class RedisCacheMetrics extends CacheMeterBinder {
+
+	private final RedisCache cache;
+
+	public RedisCacheMetrics(RedisCache cache, Iterable<Tag> tags) {
+		super(cache, cache.getName(), tags);
+		this.cache = cache;
+	}
+
+	@Override
+	protected Long size() {
+		return null;
+	}
+
+	@Override
+	protected long hitCount() {
+		return this.cache.getStatistics().getHits();
+	}
+
+	@Override
+	protected Long missCount() {
+		return this.cache.getStatistics().getMisses();
+	}
+
+	@Override
+	protected Long evictionCount() {
+		return null;
+	}
+
+	@Override
+	protected long putCount() {
+		return this.cache.getStatistics().getPuts();
+	}
+
+	@Override
+	protected void bindImplementationSpecificMetrics(MeterRegistry registry) {
+		FunctionCounter.builder("cache.removals", this.cache, (cache) -> cache.getStatistics().getDeletes())
+				.tags(getTagsWithCacheName()).description("Cache removals").register(registry);
+		FunctionCounter.builder("cache.gets", this.cache, (cache) -> cache.getStatistics().getPending())
+				.tags(getTagsWithCacheName()).tag("result", "pending").description("The number of pending requests")
+				.register(registry);
+		TimeGauge
+				.builder("cache.lock.duration", this.cache, TimeUnit.NANOSECONDS,
+						(cache) -> cache.getStatistics().getLockWaitDuration(TimeUnit.NANOSECONDS))
+				.tags(getTagsWithCacheName()).description("The time the cache has spent waiting on a lock")
+				.register(registry);
+	}
+
+}

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/cache/RedisCacheMeterBinderProviderTests.java

@@ -0,0 +1,45 @@
+/*
+ * 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.cache;
+
+import java.util.Collections;
+
+import io.micrometer.core.instrument.binder.MeterBinder;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.data.redis.cache.RedisCache;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests for {@link RedisCacheMeterBinderProvider}.
+ *
+ * @author Stephane Nicoll
+ */
+class RedisCacheMeterBinderProviderTests {
+
+	@Test
+	void redisCacheProvider() {
+		RedisCache cache = mock(RedisCache.class);
+		given(cache.getName()).willReturn("test");
+		MeterBinder meterBinder = new RedisCacheMeterBinderProvider().getMeterBinder(cache, Collections.emptyList());
+		assertThat(meterBinder).isInstanceOf(RedisCacheMetrics.class);
+	}
+
+}

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/cache/RedisCacheMetricsTests.java

@@ -0,0 +1,139 @@
+/*
+ * 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.cache;
+
+import java.util.UUID;
+import java.util.function.BiConsumer;
+
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.Tags;
+import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
+import org.junit.jupiter.api.Test;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration;
+import org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration;
+import org.springframework.boot.test.context.assertj.AssertableApplicationContext;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.boot.test.context.runner.ContextConsumer;
+import org.springframework.boot.testsupport.testcontainers.RedisContainer;
+import org.springframework.cache.annotation.EnableCaching;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.redis.cache.RedisCache;
+import org.springframework.data.redis.cache.RedisCacheManager;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link RedisCacheMetrics}.
+ *
+ * @author Stephane Nicoll
+ */
+@Testcontainers(disabledWithoutDocker = true)
+class RedisCacheMetricsTests {
+
+	@Container
+	static final RedisContainer redis = new RedisContainer();
+
+	private static final Tags TAGS = Tags.of("app", "test").and("cache", "test");
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+			.withConfiguration(AutoConfigurations.of(RedisAutoConfiguration.class, CacheAutoConfiguration.class))
+			.withUserConfiguration(CachingConfiguration.class).withPropertyValues(
+					"spring.redis.host=" + redis.getHost(), "spring.redis.port=" + redis.getFirstMappedPort(),
+					"spring.cache.type=redis", "spring.cache.redis.enable-statistics=true");
+
+	@Test
+	void cacheStatisticsAreExposed() {
+		this.contextRunner.run(withCacheMetrics((cache, meterRegistry) -> {
+			assertThat(meterRegistry.find("cache.size").tags(TAGS).functionCounter()).isNull();
+			assertThat(meterRegistry.find("cache.gets").tags(TAGS.and("result", "hit")).functionCounter()).isNotNull();
+			assertThat(meterRegistry.find("cache.gets").tags(TAGS.and("result", "miss")).functionCounter()).isNotNull();
+			assertThat(meterRegistry.find("cache.gets").tags(TAGS.and("result", "pending")).functionCounter())
+					.isNotNull();
+			assertThat(meterRegistry.find("cache.evictions").tags(TAGS).functionCounter()).isNull();
+			assertThat(meterRegistry.find("cache.puts").tags(TAGS).functionCounter()).isNotNull();
+			assertThat(meterRegistry.find("cache.removals").tags(TAGS).functionCounter()).isNotNull();
+			assertThat(meterRegistry.find("cache.lock.duration").tags(TAGS).timeGauge()).isNotNull();
+		}));
+	}
+
+	@Test
+	void cacheHitsAreExposed() {
+		this.contextRunner.run(withCacheMetrics((cache, meterRegistry) -> {
+			String key = UUID.randomUUID().toString();
+			cache.put(key, "test");
+
+			cache.get(key);
+			cache.get(key);
+			assertThat(meterRegistry.get("cache.gets").tags(TAGS.and("result", "hit")).functionCounter().count())
+					.isEqualTo(2.0d);
+		}));
+	}
+
+	@Test
+	void cacheMissesAreExposed() {
+		this.contextRunner.run(withCacheMetrics((cache, meterRegistry) -> {
+			String key = UUID.randomUUID().toString();
+			cache.get(key);
+			cache.get(key);
+			cache.get(key);
+			assertThat(meterRegistry.get("cache.gets").tags(TAGS.and("result", "miss")).functionCounter().count())
+					.isEqualTo(3.0d);
+		}));
+	}
+
+	@Test
+	void cacheMetricsMatchCacheStatistics() {
+		this.contextRunner.run((context) -> {
+			RedisCache cache = getTestCache(context);
+			RedisCacheMetrics cacheMetrics = new RedisCacheMetrics(cache, TAGS);
+			assertThat(cacheMetrics.hitCount()).isEqualTo(cache.getStatistics().getHits());
+			assertThat(cacheMetrics.missCount()).isEqualTo(cache.getStatistics().getMisses());
+			assertThat(cacheMetrics.putCount()).isEqualTo(cache.getStatistics().getPuts());
+			assertThat(cacheMetrics.size()).isNull();
+			assertThat(cacheMetrics.evictionCount()).isNull();
+		});
+	}
+
+	private ContextConsumer<AssertableApplicationContext> withCacheMetrics(
+			BiConsumer<RedisCache, MeterRegistry> stats) {
+		return (context) -> {
+			RedisCache cache = getTestCache(context);
+			SimpleMeterRegistry meterRegistry = new SimpleMeterRegistry();
+			new RedisCacheMetrics(cache, Tags.of("app", "test")).bindTo(meterRegistry);
+			stats.accept(cache, meterRegistry);
+		};
+	}
+
+	private RedisCache getTestCache(AssertableApplicationContext context) {
+		assertThat(context).hasSingleBean(RedisCacheManager.class);
+		RedisCacheManager cacheManager = context.getBean(RedisCacheManager.class);
+		RedisCache cache = (RedisCache) cacheManager.getCache("test");
+		assertThat(cache).isNotNull();
+		return cache;
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@EnableCaching
+	static class CachingConfiguration {
+
+	}
+
+}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cache/CacheProperties.java

@@ -257,6 +257,11 @@ public class CacheProperties {
 		 */
 		private boolean useKeyPrefix = true;
 
+		/**
+		 * Whether to enable cache statistics.
+		 */
+		private boolean enableStatistics;
+
 		public Duration getTimeToLive() {
 			return this.timeToLive;
 		}
@@ -289,6 +294,13 @@ public class CacheProperties {
 			this.useKeyPrefix = useKeyPrefix;
 		}
 
+		public boolean isEnableStatistics() {
+			return this.enableStatistics;
+		}
+
+		public void setEnableStatistics(boolean enableStatistics) {
+			this.enableStatistics = enableStatistics;
+		}
 	}
 
 }

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cache/RedisCacheConfiguration.java

@@ -63,6 +63,9 @@ class RedisCacheConfiguration {
 		if (!cacheNames.isEmpty()) {
 			builder.initialCacheNames(new LinkedHashSet<>(cacheNames));
 		}
+		if (cacheProperties.getRedis().isEnableStatistics()) {
+			builder.enableStatistics();
+		}
 		redisCacheManagerBuilderCustomizers.orderedStream().forEach((customizer) -> customizer.customize(builder));
 		return cacheManagerCustomizers.customize(builder.build());
 	}

spring-boot-project/spring-boot-docs/src/docs/asciidoc/production-ready-features.adoc

@@ -2303,6 +2303,7 @@ The following cache libraries are supported:
 * EhCache 2
 * Hazelcast
 * Any compliant JCache (JSR-107) implementation
+* Redis
 
 Metrics are tagged by the name of the cache and by the name of the `CacheManager` that is derived from the bean name.