Add Spring Boot HealthIndicator for Apache Geode (Client) Cache.

spring-geode-actuator/src/main/java/org/springframework/geode/boot/actuate/GeodeCacheHealthIndicator.java

@@ -0,0 +1,159 @@
+/*
+ * Copyright 2018 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
+ *
+ *     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 org.springframework.geode.boot.actuate;
+
+import java.net.URL;
+import java.util.Optional;
+import java.util.function.Function;
+
+import org.apache.geode.CancelCriterion;
+import org.apache.geode.cache.GemFireCache;
+import org.apache.geode.cache.control.ResourceManager;
+import org.apache.geode.distributed.DistributedMember;
+import org.apache.geode.distributed.DistributedSystem;
+import org.springframework.boot.actuate.health.Health;
+import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.boot.actuate.health.Status;
+import org.springframework.geode.boot.actuate.health.AbstractGeodeHealthIndicator;
+
+/**
+ * The {@link GeodeCacheHealthIndicator} class is a Spring Boot {@link HealthIndicator} providing details about
+ * the health of the {@link GemFireCache}, the {@link DistributedSystem}, this {@link DistributedMember}
+ * and the {@link ResourceManager}.
+ *
+ * @author John Blum
+ * @see java.util.Optional
+ * @see java.util.function.Function
+ * @see org.apache.geode.cache.GemFireCache
+ * @see org.apache.geode.cache.control.ResourceManager
+ * @see org.apache.geode.distributed.DistributedMember
+ * @see org.apache.geode.distributed.DistributedSystem
+ * @see org.springframework.boot.actuate.health.Health
+ * @see org.springframework.boot.actuate.health.HealthIndicator
+ * @see org.springframework.geode.boot.actuate.health.AbstractGeodeHealthIndicator
+ * @since 1.0.0
+ */
+@SuppressWarnings("unused")
+public class GeodeCacheHealthIndicator extends AbstractGeodeHealthIndicator {
+
+	private final Function<Health.Builder, Health.Builder> gemfireHealthIndicatorFunctions = withCacheDetails()
+		.andThen(withResourceManagerDetails())
+		.andThen(withDistributedSystemDetails())
+		.andThen(withDistributedMemberDetails());
+
+	/**
+	 * Default constructor to construct an uninitialized instance of {@link GeodeCacheHealthIndicator},
+	 * which will not provide any health information.
+	 */
+	public GeodeCacheHealthIndicator() {
+		super("(Client) Cache health check failed");
+	}
+
+	/**
+	 * Constructs an instance of the {@link GeodeCacheHealthIndicator} initialized with a reference to
+	 * the {@link GemFireCache} instance.
+	 *
+	 * @param gemfireCache reference to the {@link GemFireCache} instance used to collect health information.
+	 * @throws IllegalArgumentException if {@link GemFireCache} is {@literal null}.
+	 * @see org.apache.geode.cache.GemFireCache
+	 */
+	public GeodeCacheHealthIndicator(GemFireCache gemfireCache) {
+		super(gemfireCache);
+	}
+
+	/**
+	 * Return a collection of {@link Function Functions} that apply {@link HealthIndicator} information
+	 * about the {@link GemFireCache} to the {@link Health} aggregate object.
+	 *
+	 * @return a collection of {@link Function Functions} applying {@link HealthIndicator} information
+	 * about the {@link GemFireCache} to a {@link Health} object.
+	 * @see org.springframework.boot.actuate.health.Health.Builder
+	 * @see java.util.function.Function
+	 */
+	protected Function<Health.Builder, Health.Builder> getGemfireHealthIndicatorFunctions() {
+		return this.gemfireHealthIndicatorFunctions;
+	}
+
+	@Override
+	protected void doHealthCheck(Health.Builder builder) throws Exception {
+
+		if (getGemFireCache().isPresent()) {
+
+			getGemfireHealthIndicatorFunctions().apply(builder);
+
+			builder.status(getGemFireCache().map(GemFireCache::isClosed).orElse(true)
+				? Status.DOWN : Status.UP);
+
+			return;
+		}
+
+		builder.unknown();
+	}
+
+	private Function<Health.Builder, Health.Builder> withCacheDetails() {
+
+		return healthBuilder -> healthBuilder.withDetail("geode.cache.closed",
+				getGemFireCache().filter(GemFireCache::isClosed).isPresent() ? "Yes" : "No")
+			.withDetail("geode.cache.cancel-in-progress", getGemFireCache()
+				.map(GemFireCache::getCancelCriterion)
+				.filter(CancelCriterion::isCancelInProgress)
+				.isPresent() ? "Yes" : "No");
+	}
+
+	private Function<Health.Builder, Health.Builder> withDistributedMemberDetails() {
+
+		return healthBuilder -> getGemFireCache()
+			.map(GemFireCache::getDistributedSystem)
+			.map(DistributedSystem::getDistributedMember)
+			.map(distributedMember -> healthBuilder
+				.withDetail("geode.distributed-member.id", distributedMember.getId())
+				.withDetail("geode.distributed-member.name", distributedMember.getName())
+				.withDetail("geode.distributed-member.groups", distributedMember.getGroups())
+				.withDetail("geode.distributed-member.host", distributedMember.getHost())
+				.withDetail("geode.distributed-member.process-id", distributedMember.getProcessId())
+			)
+			.orElse(healthBuilder);
+	}
+
+	private Function<Health.Builder, Health.Builder> withDistributedSystemDetails() {
+
+		return healthBuilder -> getGemFireCache()
+			.map(GemFireCache::getDistributedSystem)
+			.map(distributedSystem -> healthBuilder
+				.withDetail("geode.distributed-system.connection", distributedSystem.isConnected() ? "Connected" : "Disconnected")
+				.withDetail("geode.distributed-system.reconnecting", distributedSystem.isReconnecting() ? "Yes" : "No")
+				.withDetail("geode.distributed-system.properties-location",
+					Optional.ofNullable(DistributedSystem.getPropertiesFileURL()).map(URL::toExternalForm))
+				.withDetail("geode.distributed-system.security-properties-location",
+					Optional.ofNullable(DistributedSystem.getSecurityPropertiesFileURL()).map(URL::toExternalForm))
+			)
+			.orElse(healthBuilder);
+	}
+
+	private Function<Health.Builder, Health.Builder> withResourceManagerDetails() {
+
+		return healthBuilder -> getGemFireCache()
+			.map(GemFireCache::getResourceManager)
+			.map(resourceManager -> healthBuilder
+				.withDetail("geode.resource-manager.critical-heap-percentage", resourceManager.getCriticalHeapPercentage())
+				.withDetail("geode.resource-manager.critical-off-heap-percentage", resourceManager.getCriticalOffHeapPercentage())
+				.withDetail("geode.resource-manager.eviction-heap-percentage", resourceManager.getEvictionHeapPercentage())
+				.withDetail("geode.resource-manager.eviction-off-heap-percentage", resourceManager.getEvictionOffHeapPercentage())
+			)
+			.orElse(healthBuilder);
+	}
+}