Introduce HealthIndicatorRegistry

This commit introduces HealthIndicatorRegistry which handles registration and invocation of HealthIndicator instances. Registering new HealthIndicator instances is now possible in runtime.

The default implementation offers the option to run the registered health indicators in parallel.

Author: vpavic

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/autoconfigure/EndpointAutoConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2016 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.
@@ -19,7 +19,6 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -46,8 +45,9 @@
 import org.springframework.boot.actuate.endpoint.RequestMappingEndpoint;
 import org.springframework.boot.actuate.endpoint.ShutdownEndpoint;
 import org.springframework.boot.actuate.endpoint.TraceEndpoint;
+import org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry;
 import org.springframework.boot.actuate.health.HealthAggregator;
-import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.boot.actuate.health.HealthIndicatorRegistry;
 import org.springframework.boot.actuate.health.OrderedHealthAggregator;
 import org.springframework.boot.actuate.trace.InMemoryTraceRepository;
 import org.springframework.boot.actuate.trace.TraceRepository;
@@ -81,6 +81,7 @@
  * @author Christian Dupuis
  * @author Stephane Nicoll
  * @author Eddú Meléndez
+ * @author Vedran Pavic
  */
 @Configuration
 @AutoConfigureAfter({ FlywayAutoConfiguration.class, LiquibaseAutoConfiguration.class })
@@ -94,7 +95,7 @@ public class EndpointAutoConfiguration {
 	private HealthAggregator healthAggregator = new OrderedHealthAggregator();
 
 	@Autowired(required = false)
-	private Map<String, HealthIndicator> healthIndicators = new HashMap<String, HealthIndicator>();
+	private HealthIndicatorRegistry healthIndicatorRegistry = new DefaultHealthIndicatorRegistry();
 
 	@Autowired(required = false)
 	private Collection<PublicMetrics> publicMetrics;
@@ -111,7 +112,7 @@ public EnvironmentEndpoint environmentEndpoint() {
 	@Bean
 	@ConditionalOnMissingBean
 	public HealthEndpoint healthEndpoint() {
-		return new HealthEndpoint(this.healthAggregator, this.healthIndicators);
+		return new HealthEndpoint(this.healthAggregator, this.healthIndicatorRegistry);
 	}
 
 	@Bean

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/autoconfigure/HealthIndicatorAutoConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2016 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.
@@ -27,18 +27,23 @@
 import org.elasticsearch.client.Client;
 
 import org.springframework.amqp.rabbit.core.RabbitTemplate;
+import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.boot.actuate.health.ApplicationHealthIndicator;
 import org.springframework.boot.actuate.health.CassandraHealthIndicator;
 import org.springframework.boot.actuate.health.CompositeHealthIndicator;
 import org.springframework.boot.actuate.health.DataSourceHealthIndicator;
+import org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistry;
+import org.springframework.boot.actuate.health.DefaultHealthIndicatorRegistryProperties;
 import org.springframework.boot.actuate.health.DiskSpaceHealthIndicator;
 import org.springframework.boot.actuate.health.DiskSpaceHealthIndicatorProperties;
 import org.springframework.boot.actuate.health.ElasticsearchHealthIndicator;
 import org.springframework.boot.actuate.health.ElasticsearchHealthIndicatorProperties;
 import org.springframework.boot.actuate.health.HealthAggregator;
 import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.boot.actuate.health.HealthIndicatorRegistry;
 import org.springframework.boot.actuate.health.JmsHealthIndicator;
 import org.springframework.boot.actuate.health.MailHealthIndicator;
 import org.springframework.boot.actuate.health.MongoHealthIndicator;
@@ -84,6 +89,7 @@
  * @author Stephane Nicoll
  * @author Phillip Webb
  * @author Tommy Ludwig
+ * @author Vedran Pavic
  * @since 1.1.0
  */
 @Configuration
@@ -100,6 +106,14 @@ public class HealthIndicatorAutoConfiguration {
 	@Autowired
 	private HealthIndicatorAutoConfigurationProperties configurationProperties = new HealthIndicatorAutoConfigurationProperties();
 
+	@Autowired
+	private HealthIndicatorRegistry healthIndicatorRegistry;
+
+	@Bean
+	public HealthIndicatorRegistryPostProcessor healthIndicatorRegistryPostProcessor() {
+		return new HealthIndicatorRegistryPostProcessor(this.healthIndicatorRegistry);
+	}
+
 	@Bean
 	@ConditionalOnMissingBean(HealthAggregator.class)
 	public OrderedHealthAggregator healthAggregator() {
@@ -116,6 +130,21 @@ public ApplicationHealthIndicator applicationHealthIndicator() {
 		return new ApplicationHealthIndicator();
 	}
 
+	@Configuration
+	@ConditionalOnMissingBean(HealthIndicatorRegistry.class)
+	@EnableConfigurationProperties(DefaultHealthIndicatorRegistryProperties.class)
+	public static class HealthIndicatorRegistryAutoConfiguration {
+
+		@Autowired
+		private DefaultHealthIndicatorRegistryProperties properties;
+
+		@Bean
+		public HealthIndicatorRegistry healthIndicatorRegistry() {
+			return new DefaultHealthIndicatorRegistry(this.properties);
+		}
+
+	}
+
 	/**
 	 * Base class for configurations that can combine source beans using a
 	 * {@link CompositeHealthIndicator}.
@@ -363,4 +392,51 @@ protected ElasticsearchHealthIndicator createHealthIndicator(Client client) {
 
 	}
 
+	/**
+	 * A {@link BeanPostProcessor} that registers {@link HealthIndicator} beans with a
+	 * {@link HealthIndicatorRegistry}.
+	 */
+	private static class HealthIndicatorRegistryPostProcessor implements BeanPostProcessor {
+
+		private HealthIndicatorRegistry healthIndicatorRegistry;
+
+		HealthIndicatorRegistryPostProcessor(HealthIndicatorRegistry healthIndicatorRegistry) {
+			this.healthIndicatorRegistry = healthIndicatorRegistry;
+		}
+
+		@Override
+		public Object postProcessBeforeInitialization(Object bean, String beanName)
+				throws BeansException {
+			return bean;
+		}
+
+		@Override
+		public Object postProcessAfterInitialization(Object bean, String beanName)
+				throws BeansException {
+			if (bean instanceof HealthIndicator) {
+				postProcessHealthIndicator((HealthIndicator) bean, beanName);
+			}
+			return bean;
+		}
+
+		private void postProcessHealthIndicator(
+				HealthIndicator healthIndicator, String beanName) {
+			this.healthIndicatorRegistry.register(getKey(beanName), healthIndicator);
+		}
+
+		/**
+		 * Turns the bean name into a key that can be used in the map of health information.
+		 * @param name the bean name
+		 * @return the key
+		 */
+		private String getKey(String name) {
+			int index = name.toLowerCase().indexOf("healthindicator");
+			if (index > 0) {
+				return name.substring(0, index);
+			}
+			return name;
+		}
+
+	}
+
 }

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/HealthEndpoint.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2016 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.
@@ -18,10 +18,10 @@
 
 import java.util.Map;
 
-import org.springframework.boot.actuate.health.CompositeHealthIndicator;
 import org.springframework.boot.actuate.health.Health;
 import org.springframework.boot.actuate.health.HealthAggregator;
 import org.springframework.boot.actuate.health.HealthIndicator;
+import org.springframework.boot.actuate.health.HealthIndicatorRegistry;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.util.Assert;
 
@@ -31,11 +31,13 @@
  * @author Dave Syer
  * @author Christian Dupuis
  * @author Andy Wilkinson
+ * @author Vedran Pavic
  */
 @ConfigurationProperties(prefix = "endpoints.health", ignoreUnknownFields = true)
 public class HealthEndpoint extends AbstractEndpoint<Health> {
 
-	private final HealthIndicator healthIndicator;
+	private final HealthAggregator healthAggregator;
+	private final HealthIndicatorRegistry healthIndicatorRegistry;
 
 	/**
 	 * Time to live for cached result, in milliseconds.
@@ -45,19 +47,16 @@ public class HealthEndpoint extends AbstractEndpoint<Health> {
 	/**
 	 * Create a new {@link HealthIndicator} instance.
 	 * @param healthAggregator the health aggregator
-	 * @param healthIndicators the health indicators
+	 * @param healthIndicatorRegistry the health indicator registry
 	 */
 	public HealthEndpoint(HealthAggregator healthAggregator,
-			Map<String, HealthIndicator> healthIndicators) {
+			HealthIndicatorRegistry healthIndicatorRegistry) {
 		super("health", false);
 		Assert.notNull(healthAggregator, "HealthAggregator must not be null");
-		Assert.notNull(healthIndicators, "HealthIndicators must not be null");
-		CompositeHealthIndicator healthIndicator = new CompositeHealthIndicator(
-				healthAggregator);
-		for (Map.Entry<String, HealthIndicator> entry : healthIndicators.entrySet()) {
-			healthIndicator.addHealthIndicator(getKey(entry.getKey()), entry.getValue());
-		}
-		this.healthIndicator = healthIndicator;
+		Assert.notNull(healthIndicatorRegistry,
+				"healthIndicatorRegistry must not be null");
+		this.healthAggregator = healthAggregator;
+		this.healthIndicatorRegistry = healthIndicatorRegistry;
 	}
 
 	/**
@@ -78,19 +77,8 @@ public void setTimeToLive(long ttl) {
 	 */
 	@Override
 	public Health invoke() {
-		return this.healthIndicator.health();
+		Map<String, Health> healths = this.healthIndicatorRegistry.runHealthIndicators();
+		return this.healthAggregator.aggregate(healths);
 	}
 
-	/**
-	 * Turns the bean name into a key that can be used in the map of health information.
-	 * @param name the bean name
-	 * @return the key
-	 */
-	private String getKey(String name) {
-		int index = name.toLowerCase().indexOf("healthindicator");
-		if (index > 0) {
-			return name.substring(0, index);
-		}
-		return name;
-	}
 }

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/health/DefaultHealthIndicatorRegistry.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2012-2016 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.boot.actuate.health;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+
+import org.springframework.util.Assert;
+
+/**
+ * Default implementation of {@link HealthIndicatorRegistry}.
+ *
+ * @author Vedran Pavic
+ */
+public class DefaultHealthIndicatorRegistry implements HealthIndicatorRegistry {
+
+	private final Map<String, HealthIndicator> healthIndicators =
+			new HashMap<String, HealthIndicator>();
+
+	private DefaultHealthIndicatorRegistryProperties properties;
+
+	private ExecutorService executor;
+
+	/**
+	 * Create a {@link DefaultHealthIndicatorRegistry} instance.
+	 * @param properties the configuration properties
+	 */
+	public DefaultHealthIndicatorRegistry(DefaultHealthIndicatorRegistryProperties properties) {
+		Assert.notNull(properties, "Properties must not be null");
+		this.properties = properties;
+		this.executor = Executors.newFixedThreadPool(this.properties.getThreadCount());
+	}
+
+	/**
+	 * Create a {@link DefaultHealthIndicatorRegistry} instance.
+	 */
+	public DefaultHealthIndicatorRegistry() {
+		this(new DefaultHealthIndicatorRegistryProperties());
+	}
+
+	@Override
+	public void register(String name, HealthIndicator healthIndicator) {
+		this.healthIndicators.put(name, healthIndicator);
+	}
+
+	@Override
+	public void unregister(String name) {
+		this.healthIndicators.remove(name);
+	}
+
+	@Override
+	public Set<String> getRegisteredNames() {
+		return Collections.unmodifiableSet(this.healthIndicators.keySet());
+	}
+
+	@Override
+	public Health runHealthIndicator(String name) {
+		HealthIndicator healthIndicator = this.healthIndicators.get(name);
+		Assert.notNull(healthIndicator, "HealthIndicator " + name + " does not exist");
+		return healthIndicator.health();
+	}
+
+	@Override
+	public Map<String, Health> runHealthIndicators() {
+		Map<String, Health> healths =
+				new HashMap<String, Health>(this.healthIndicators.size());
+		if (this.properties.isRunInParallel()) {
+			Assert.notNull(this.executor, "Executor must not be null");
+			Map<String, Future<Health>> futures =
+					new HashMap<String, Future<Health>>(this.healthIndicators.size());
+			for (final Map.Entry<String, HealthIndicator> entry : this.healthIndicators.entrySet()) {
+				Future<Health> future = this.executor.submit(new Callable<Health>() {
+					@Override
+					public Health call() throws Exception {
+						return entry.getValue().health();
+					}
+				});
+				futures.put(entry.getKey(), future);
+			}
+			for (Map.Entry<String, Future<Health>> entry : futures.entrySet()) {
+				try {
+					healths.put(entry.getKey(), entry.getValue().get());
+				}
+				catch (Exception e) {
+					e.printStackTrace();
+				}
+			}
+		}
+		else {
+			for (Map.Entry<String, HealthIndicator> entry : this.healthIndicators.entrySet()) {
+				healths.put(entry.getKey(), entry.getValue().health());
+			}
+		}
+		return healths;
+	}
+
+}