Extract metric writers into a MetricExporters composite

Adds a separate exporter per MetricWriter and allows individual
configuration of exporters for fine-grained control of schedules
and patterns etc.

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

@@ -16,8 +16,9 @@
 
 package org.springframework.boot.actuate.autoconfigure;
 
-import java.util.ArrayList;
-import java.util.List;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
@@ -30,15 +31,15 @@ import org.springframework.boot.actuate.metrics.buffer.CounterBuffers;
 import org.springframework.boot.actuate.metrics.buffer.GaugeBuffers;
 import org.springframework.boot.actuate.metrics.export.Exporter;
 import org.springframework.boot.actuate.metrics.export.MetricCopyExporter;
+import org.springframework.boot.actuate.metrics.export.MetricExportProperties;
+import org.springframework.boot.actuate.metrics.export.MetricExporters;
 import org.springframework.boot.actuate.metrics.reader.MetricReader;
 import org.springframework.boot.actuate.metrics.repository.InMemoryMetricRepository;
 import org.springframework.boot.actuate.metrics.repository.MetricRepository;
-import org.springframework.boot.actuate.metrics.writer.CompositeMetricWriter;
 import org.springframework.boot.actuate.metrics.writer.DefaultCounterService;
 import org.springframework.boot.actuate.metrics.writer.DefaultGaugeService;
 import org.springframework.boot.actuate.metrics.writer.MetricWriter;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnJava;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnJava.JavaVersion;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnJava.Range;
@@ -50,7 +51,6 @@ import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Primary;
 import org.springframework.messaging.MessageChannel;
 import org.springframework.scheduling.annotation.EnableScheduling;
-import org.springframework.scheduling.annotation.Scheduled;
 
 import com.codahale.metrics.MetricRegistry;
 
@@ -91,7 +91,7 @@ import com.codahale.metrics.MetricRegistry;
  * @author Dave Syer
  */
 @Configuration
-@EnableConfigurationProperties(MetricsProperties.class)
+@EnableConfigurationProperties(MetricExportProperties.class)
 public class MetricRepositoryAutoConfiguration {
 
 	@Configuration
@@ -173,10 +173,10 @@ public class MetricRepositoryAutoConfiguration {
 	static class DefaultMetricsExporterConfiguration {
 
 		@Autowired(required = false)
-		private List<MetricWriter> writers;
+		private Map<String, MetricWriter> writers = Collections.emptyMap();
 
 		@Autowired
-		private MetricsProperties metrics;
+		private MetricExportProperties metrics;
 
 		@Autowired(required = false)
 		@Qualifier("actuatorMetricRepository")
@@ -184,27 +184,19 @@ public class MetricRepositoryAutoConfiguration {
 
 		@Bean
 		@ConditionalOnMissingBean
-		@ConditionalOnBean(MetricWriter.class)
-		public MetricCopyExporter metricWritersMetricExporter(MetricReader reader) {
-			List<MetricWriter> writers = new ArrayList<MetricWriter>(this.writers);
+		public MetricExporters metricWritersMetricExporter(MetricReader reader) {
+			Map<String, MetricWriter> writers = new HashMap<String, MetricWriter>(
+					this.writers);
 			if (this.actuatorMetricRepository != null
-					&& writers.contains(this.actuatorMetricRepository)) {
-				writers.remove(this.actuatorMetricRepository);
-			}
-			MetricCopyExporter exporter = new MetricCopyExporter(reader,
-					new CompositeMetricWriter(writers)) {
-				@Scheduled(fixedDelayString = "${spring.metrics.export.delayMillis:5000}")
-				@Override
-				public void export() {
-					super.export();
+					&& writers.containsValue(this.actuatorMetricRepository)) {
+				for (String name : this.writers.keySet()) {
+					if (writers.get(name).equals(this.actuatorMetricRepository)) {
+						writers.remove(name);
+					}
 				}
-			};
-			if (this.metrics.getExport().getIncludes() != null
-					|| this.metrics.getExport().getExcludes() != null) {
-				exporter.setIncludes(this.metrics.getExport().getIncludes());
-				exporter.setExcludes(this.metrics.getExport().getExcludes());
 			}
-			return exporter;
+			MetricExporters exporters = new MetricExporters(reader, writers, this.metrics);
+			return exporters;
 		}
 	}
 

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/export/MetricExportProperties.java

@@ -14,28 +14,112 @@
  * limitations under the License.
  */
 
-package org.springframework.boot.actuate.autoconfigure;
+package org.springframework.boot.actuate.metrics.export;
+
+import java.util.Arrays;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import javax.annotation.PostConstruct;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.util.PatternMatchUtils;
 
 /**
  * @author Dave Syer
  */
-@ConfigurationProperties("spring.metrics")
-public class MetricsProperties {
+@ConfigurationProperties("spring.metrics.export")
+public class MetricExportProperties {
+
+	/**
+	 * Flag to disable all metric exports (assuming any MetricWriters are available).
+	 */
+	private boolean enabled = true;
 
 	private Export export = new Export();
 
-	public Export getExport() {
+	private Map<String, Export> writers = new LinkedHashMap<String, Export>();
+
+	/**
+	 * Default values for trigger configuration for all writers. Can also be set by
+	 * including a writer with <code>name="*"</code>.
+	 *
+	 * @return the default trigger configuration
+	 */
+	public Export getDefault() {
 		return this.export;
 	}
 
+	/**
+	 * Configuration for triggers on individual named writers. Each value can individually
+	 * specify a name pattern explicitly, or else the map key will be used if the name is
+	 * not set.
+	 *
+	 * @return the writers
+	 */
+	public Map<String, Export> getWriters() {
+		return this.writers;
+	}
+
+	@PostConstruct
+	public void setDefaults() {
+		Export defaults = null;
+		for (Entry<String, Export> entry : this.writers.entrySet()) {
+			String key = entry.getKey();
+			Export value = entry.getValue();
+			if (value.getNames() == null || value.getNames().length == 0) {
+				value.setNames(new String[] { key });
+			}
+			if (Arrays.asList(value.getNames()).contains("*")) {
+				defaults = value;
+			}
+		}
+		if (defaults == null) {
+			this.export.setNames(new String[] { "*" });
+			this.writers.put("*", this.export);
+			defaults = this.export;
+		}
+		if (defaults.isIgnoreTimestamps() == null) {
+			defaults.setIgnoreTimestamps(false);
+		}
+		if (defaults.isSendLatest() == null) {
+			defaults.setSendLatest(true);
+		}
+		if (defaults.getDelayMillis() == null) {
+			defaults.setDelayMillis(5000);
+		}
+		for (Export value : this.writers.values()) {
+			if (value.isIgnoreTimestamps() == null) {
+				value.setIgnoreTimestamps(false);
+			}
+			if (value.isSendLatest() == null) {
+				value.setSendLatest(true);
+			}
+			if (value.getDelayMillis() == null) {
+				value.setDelayMillis(5000);
+			}
+		}
+	}
+
+	public boolean isEnabled() {
+		return this.enabled;
+	}
+
+	public void setEnabled(boolean enabled) {
+		this.enabled = enabled;
+	}
+
 	public static class Export {
+		/**
+		 * Names (or patterns) for bean names that this configuration applies to.
+		 */
+		private String[] names;
 		/**
 		 * Delay in milliseconds between export ticks. Metrics are exported to external
 		 * sources on a schedule with this delay.
 		 */
-		private long delayMillis;
+		private Long delayMillis;
 
 		/**
 		 * Flag to enable metric export (assuming a MetricWriter is available).
@@ -46,12 +130,26 @@ public class MetricsProperties {
 		 * Flag to switch off any available optimizations based on not exporting unchanged
 		 * metric values.
 		 */
-		private boolean ignoreTimestamps = false;
+		private Boolean sendLatest;
+
+		/**
+		 * Flag to ignore timestamps completely. If true, send all metrics all the time,
+		 * including ones that haven't changed since startup.
+		 */
+		private Boolean ignoreTimestamps;
 
 		private String[] includes;
 
 		private String[] excludes;
 
+		public String[] getNames() {
+			return this.names;
+		}
+
+		public void setNames(String[] names) {
+			this.names = names;
+		}
+
 		public String[] getIncludes() {
 			return this.includes;
 		}
@@ -60,14 +158,14 @@ public class MetricsProperties {
 			this.includes = includes;
 		}
 
-		public String[] getExcludes() {
-			return this.excludes;
-		}
-
 		public void setExcludes(String[] excludes) {
 			this.excludes = excludes;
 		}
 
+		public String[] getExcludes() {
+			return this.excludes;
+		}
+
 		public boolean isEnabled() {
 			return this.enabled;
 		}
@@ -76,7 +174,7 @@ public class MetricsProperties {
 			this.enabled = enabled;
 		}
 
-		public long getDelayMillis() {
+		public Long getDelayMillis() {
 			return this.delayMillis;
 		}
 
@@ -84,12 +182,34 @@ public class MetricsProperties {
 			this.delayMillis = delayMillis;
 		}
 
-		public boolean isIgnoreTimestamps() {
+		public Boolean isIgnoreTimestamps() {
 			return this.ignoreTimestamps;
 		}
 
 		public void setIgnoreTimestamps(boolean ignoreTimestamps) {
 			this.ignoreTimestamps = ignoreTimestamps;
 		}
+
+		public Boolean isSendLatest() {
+			return this.sendLatest;
+		}
+
+		public void setSendLatest(boolean sendLatest) {
+			this.sendLatest = sendLatest;
+		}
+	}
+
+	/**
+	 * Find a matching trigger configuration.
+	 * @param name the bean name to match
+	 * @return a matching configuration if there is one
+	 */
+	public Export findExport(String name) {
+		for (Export value : this.writers.values()) {
+			if (PatternMatchUtils.simpleMatch(value.getNames(), name)) {
+				return value;
+			}
+		}
+		return null;
 	}
 }

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/export/MetricExporters.java

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2012-2015 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.metrics.export;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import org.springframework.boot.actuate.metrics.export.MetricExportProperties.Export;
+import org.springframework.boot.actuate.metrics.reader.MetricReader;
+import org.springframework.boot.actuate.metrics.writer.MetricWriter;
+import org.springframework.scheduling.annotation.SchedulingConfigurer;
+import org.springframework.scheduling.config.IntervalTask;
+import org.springframework.scheduling.config.ScheduledTaskRegistrar;
+
+/**
+ * @author Dave Syer
+ */
+public class MetricExporters implements SchedulingConfigurer {
+
+	private MetricExportProperties export;
+
+	private Map<String, MetricWriter> writers;
+
+	private Map<String, Exporter> exporters = new HashMap<String, Exporter>();
+
+	private MetricReader reader;
+
+	public MetricExporters(MetricReader reader, Map<String, MetricWriter> writers,
+			MetricExportProperties export) {
+		this.reader = reader;
+		this.export = export;
+		this.writers = writers;
+	}
+
+	public Map<String, Exporter> getExporters() {
+		return this.exporters;
+	}
+
+	@Override
+	public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
+
+		for (Entry<String, MetricWriter> entry : this.writers.entrySet()) {
+			String name = entry.getKey();
+			Export trigger = this.export.findExport(name);
+
+			if (trigger != null) {
+
+				MetricWriter writer = entry.getValue();
+				final MetricCopyExporter exporter = new MetricCopyExporter(this.reader,
+						writer);
+				if (trigger.getIncludes() != null || trigger.getExcludes() != null) {
+					exporter.setIncludes(trigger.getIncludes());
+					exporter.setExcludes(trigger.getExcludes());
+				}
+				exporter.setIgnoreTimestamps(trigger.isIgnoreTimestamps());
+				exporter.setSendLatest(trigger.isSendLatest());
+
+				this.exporters.put(name, exporter);
+
+				taskRegistrar.addFixedDelayTask(new IntervalTask(new Runnable() {
+					@Override
+					public void run() {
+						exporter.export();
+					}
+				}, trigger.getDelayMillis(), trigger.getDelayMillis()));
+
+			}
+
+		}
+
+	}
+
+}

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/autoconfigure/MetricRepositoryAutoConfigurationTests.java

@@ -27,6 +27,7 @@ import org.springframework.boot.actuate.metrics.buffer.BufferCounterService;
 import org.springframework.boot.actuate.metrics.buffer.BufferGaugeService;
 import org.springframework.boot.actuate.metrics.dropwizard.DropwizardMetricServices;
 import org.springframework.boot.actuate.metrics.export.MetricCopyExporter;
+import org.springframework.boot.actuate.metrics.export.MetricExporters;
 import org.springframework.boot.actuate.metrics.reader.MetricReader;
 import org.springframework.boot.actuate.metrics.reader.PrefixMetricReader;
 import org.springframework.boot.actuate.metrics.writer.MetricWriter;
@@ -86,7 +87,7 @@ public class MetricRepositoryAutoConfigurationTests {
 				MessageChannelConfiguration.class, MetricsChannelAutoConfiguration.class,
 				MetricRepositoryAutoConfiguration.class,
 				PropertyPlaceholderAutoConfiguration.class);
-		MetricCopyExporter exporter = this.context.getBean(MetricCopyExporter.class);
+		MetricExporters exporter = this.context.getBean(MetricExporters.class);
 		assertNotNull(exporter);
 	}
 
@@ -98,7 +99,9 @@ public class MetricRepositoryAutoConfigurationTests {
 		GaugeService gaugeService = this.context.getBean(GaugeService.class);
 		assertNotNull(gaugeService);
 		gaugeService.submit("foo", 2.7);
-		MetricCopyExporter exporter = this.context.getBean(MetricCopyExporter.class);
+		MetricExporters exporters = this.context.getBean(MetricExporters.class);
+		MetricCopyExporter exporter = (MetricCopyExporter) exporters.getExporters().get(
+				"writer");
 		exporter.setIgnoreTimestamps(true);
 		exporter.export();
 		MetricWriter writer = this.context.getBean("writer", MetricWriter.class);