Add more runtime metrics like information about heap, class loading and threads to the metrics infrastructure

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2013 the original author or authors.
+ * Copyright 2012-2014 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.
@@ -16,6 +16,10 @@
 
 package org.springframework.boot.actuate.endpoint;
 
+import java.lang.management.ClassLoadingMXBean;
+import java.lang.management.ManagementFactory;
+import java.lang.management.MemoryUsage;
+import java.lang.management.ThreadMXBean;
 import java.util.Collection;
 import java.util.LinkedHashSet;
 
@@ -28,6 +32,7 @@ import org.springframework.util.Assert;
  * {@link MetricReader} along with memory information.
  * 
  * @author Dave Syer
+ * @author Christian Dupuis
  */
 public class VanillaPublicMetrics implements PublicMetrics {
 
@@ -44,13 +49,65 @@ public class VanillaPublicMetrics implements PublicMetrics {
 		for (Metric<?> metric : this.reader.findAll()) {
 			result.add(metric);
 		}
+
+		addMetrics(result);
+		addHeapMetrics(result);
+		addThreadMetrics(result);
+		addClassLoadingMetrics(result);
+
+		return result;
+	}
+
+	/**
+	 * Add basic system metrics.
+	 */
+	protected void addMetrics(Collection<Metric<?>> result) {
 		result.add(new Metric<Long>("mem",
 				new Long(Runtime.getRuntime().totalMemory()) / 1024));
 		result.add(new Metric<Long>("mem.free", new Long(Runtime.getRuntime()
 				.freeMemory()) / 1024));
 		result.add(new Metric<Integer>("processors", Runtime.getRuntime()
 				.availableProcessors()));
-		return result;
+		// Add JVM uptime in ms
+		result.add(new Metric<Long>("uptime", new Long(ManagementFactory
+				.getRuntimeMXBean().getUptime())));
+	}
+
+	/**
+	 * Add JVM heap metrics.
+	 */
+	protected void addHeapMetrics(Collection<Metric<?>> result) {
+		MemoryUsage memoryUsage = ManagementFactory.getMemoryMXBean()
+				.getHeapMemoryUsage();
+		result.add(new Metric<Long>("heap.committed", memoryUsage.getCommitted() / 1024));
+		result.add(new Metric<Long>("heap.init", memoryUsage.getInit() / 1024));
+		result.add(new Metric<Long>("heap.used", memoryUsage.getUsed() / 1024));
+		result.add(new Metric<Long>("heap", memoryUsage.getMax() / 1024));
+	}
+
+	/**
+	 * Add thread metrics.
+	 */
+	protected void addThreadMetrics(Collection<Metric<?>> result) {
+		ThreadMXBean threadMxBean = ManagementFactory.getThreadMXBean();
+		result.add(new Metric<Long>("threads.peak", new Long(threadMxBean
+				.getPeakThreadCount())));
+		result.add(new Metric<Long>("threads.deamon", new Long(threadMxBean
+				.getDaemonThreadCount())));
+		result.add(new Metric<Long>("threads", new Long(threadMxBean.getThreadCount())));
+	}
+
+	/**
+	 * Add class loading metrics.
+	 */
+	protected void addClassLoadingMetrics(Collection<Metric<?>> result) {
+		ClassLoadingMXBean classLoadingMxBean = ManagementFactory.getClassLoadingMXBean();
+		result.add(new Metric<Long>("classes", new Long(classLoadingMxBean
+				.getLoadedClassCount())));
+		result.add(new Metric<Long>("classes.loaded", new Long(classLoadingMxBean
+				.getTotalLoadedClassCount())));
+		result.add(new Metric<Long>("classes.unloaded", new Long(classLoadingMxBean
+				.getUnloadedClassCount())));
 	}
 
 }

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/VanillaPublicMetricsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2013 the original author or authors.
+ * Copyright 2012-2014 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.
@@ -32,6 +32,7 @@ import static org.junit.Assert.assertTrue;
  * Tests for {@link VanillaPublicMetrics}.
  * 
  * @author Phillip Webb
+ * @author Christian Dupuis
  */
 public class VanillaPublicMetricsTests {
 
@@ -48,4 +49,32 @@ public class VanillaPublicMetricsTests {
 		assertTrue(results.containsKey("mem.free"));
 		assertThat(results.get("a").getValue().doubleValue(), equalTo(0.5));
 	}
+
+	@Test
+	public void testSystemMetrics() throws Exception {
+		InMemoryMetricRepository repository = new InMemoryMetricRepository();
+		repository.set(new Metric<Double>("a", 0.5, new Date()));
+		VanillaPublicMetrics publicMetrics = new VanillaPublicMetrics(repository);
+		Map<String, Metric<?>> results = new HashMap<String, Metric<?>>();
+		for (Metric<?> metric : publicMetrics.metrics()) {
+			results.put(metric.getName(), metric);
+		}
+		assertTrue(results.containsKey("mem"));
+		assertTrue(results.containsKey("mem.free"));
+		assertTrue(results.containsKey("processors"));
+		assertTrue(results.containsKey("uptime"));
+
+		assertTrue(results.containsKey("heap.committed"));
+		assertTrue(results.containsKey("heap.init"));
+		assertTrue(results.containsKey("heap.used"));
+		assertTrue(results.containsKey("heap"));
+
+		assertTrue(results.containsKey("threads.peak"));
+		assertTrue(results.containsKey("threads.deamon"));
+		assertTrue(results.containsKey("threads"));
+
+		assertTrue(results.containsKey("classes.loaded"));
+		assertTrue(results.containsKey("classes.unloaded"));
+		assertTrue(results.containsKey("classes"));
+	}
 }

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

@@ -578,16 +578,27 @@ decrement). Metrics for all HTTP requests are automatically recorded, so if you
 		"counter.status.401.root": 4,
 		"gauge.response.root": 2,
 		"gauge.response.metrics": 3,
-		"mem": 466944,
+		"classes": 5808,
-		"mem.free": 410117,
+		"classes.loaded": 5808,
-		"processors": 8
+		"classes.unloaded": 0,
+		"heap": 3728384,
+		"heap.committed": 986624,
+		"heap.init": 262144,
+		"heap.used": 52765,
+		"mem": 986624,
+		"mem.free": 933858,
+		"processors": 8,
+		"threads": 15,
+		"threads.deamon": 11,
+		"threads.peak": 15,
+		"uptime": 494836
 	}
 ----
 
-Here we can see basic `memory` and `processor` information along with some HTTP metrics.
+Here we can see basic `memory`, `heap`, `class loading`, `processor` and `thread pool`
-In this instance the `root` (``/'') and `/metrics` URLs have returned `HTTP 200` responses
+information along with some HTTP metrics. In this instance the `root` (``/'') and `/metrics`
-`20` and `3` times respectively. It also appears that the `root` URL returned `HTTP 401`
+URLs have returned `HTTP 200` responses `20` and `3` times respectively. It also appears 
-(unauthorized) `4` times.
+that the `root` URL returned `HTTP 401` (unauthorized) `4` times.
 
 The `gauge` shows the last response time for a request. So the last request to `root` took
 `2ms` to respond and the last to `/metrics` took `3ms`.