Add startup time metrics

See gh-27878

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/startup/StartupTimeMetricsAutoConfiguration.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2012-2021 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.autoconfigure.metrics.startup;
+
+import io.micrometer.core.instrument.MeterRegistry;
+
+import org.springframework.boot.actuate.autoconfigure.metrics.CompositeMeterRegistryAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.metrics.MetricsAutoConfiguration;
+import org.springframework.boot.actuate.metrics.startup.StartupTimeMetrics;
+import org.springframework.boot.autoconfigure.AutoConfigureAfter;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * {@link EnableAutoConfiguration Auto-configuration} for the {@link StartupTimeMetrics}.
+ *
+ * @author Chris Bono
+ * @since 2.6.0
+ */
+@Configuration(proxyBeanMethods = false)
+@AutoConfigureAfter({ MetricsAutoConfiguration.class, CompositeMeterRegistryAutoConfiguration.class })
+@ConditionalOnClass(MeterRegistry.class)
+@ConditionalOnBean(MeterRegistry.class)
+public class StartupTimeMetricsAutoConfiguration {
+
+	@Bean
+	@ConditionalOnMissingBean
+	StartupTimeMetrics startupTimeMetrics(MeterRegistry meterRegistry) {
+		return new StartupTimeMetrics(meterRegistry);
+	}
+
+}

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/startup/package-info.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2012-2021 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.
+ */
+
+/**
+ * Auto-configuration for actuator startup time metrics.
+ */
+package org.springframework.boot.actuate.autoconfigure.metrics.startup;

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/resources/META-INF/spring.factories

@@ -75,6 +75,7 @@ org.springframework.boot.actuate.autoconfigure.metrics.mongo.MongoMetricsAutoCon
 org.springframework.boot.actuate.autoconfigure.metrics.orm.jpa.HibernateMetricsAutoConfiguration,\
 org.springframework.boot.actuate.autoconfigure.metrics.r2dbc.ConnectionPoolMetricsAutoConfiguration,\
 org.springframework.boot.actuate.autoconfigure.metrics.redis.LettuceMetricsAutoConfiguration,\
+org.springframework.boot.actuate.autoconfigure.metrics.startup.StartupTimeMetricsAutoConfiguration,\
 org.springframework.boot.actuate.autoconfigure.metrics.task.TaskExecutorMetricsAutoConfiguration,\
 org.springframework.boot.actuate.autoconfigure.metrics.web.client.HttpClientMetricsAutoConfiguration,\
 org.springframework.boot.actuate.autoconfigure.metrics.web.jetty.JettyMetricsAutoConfiguration,\

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/startup/StartupTimeMetricsAutoConfigurationTests.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2012-2021 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.autoconfigure.metrics.startup;
+
+import java.time.Duration;
+
+import io.micrometer.core.instrument.Tags;
+import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.actuate.autoconfigure.metrics.test.MetricsRun;
+import org.springframework.boot.actuate.metrics.startup.StartupTimeMetrics;
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.context.event.ApplicationReadyEvent;
+import org.springframework.boot.context.event.ApplicationStartedEvent;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link StartupTimeMetricsAutoConfiguration}.
+ *
+ * @author Chris Bono
+ */
+class StartupTimeMetricsAutoConfigurationTests {
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner().with(MetricsRun.simple())
+			.withConfiguration(AutoConfigurations.of(StartupTimeMetricsAutoConfiguration.class));
+
+	@Test
+	void startupTimeMetricsAreRecorded() {
+		this.contextRunner.run((context) -> {
+			context.publishEvent(new ApplicationStartedEvent(new SpringApplication(), null,
+					context.getSourceApplicationContext(), Duration.ofMillis(2500)));
+			context.publishEvent(new ApplicationReadyEvent(new SpringApplication(), null,
+					context.getSourceApplicationContext(), Duration.ofMillis(3000)));
+			assertThat(context).hasSingleBean(StartupTimeMetrics.class);
+			SimpleMeterRegistry registry = context.getBean(SimpleMeterRegistry.class);
+			assertThat(registry.find("application.started.time").timeGauge()).isNotNull();
+			assertThat(registry.find("application.ready.time").timeGauge()).isNotNull();
+		});
+	}
+
+	@Test
+	void startupTimeMetricsCanBeDisabled() {
+		this.contextRunner.withPropertyValues("management.metrics.enable.application.started.time:false",
+				"management.metrics.enable.application.ready.time:false").run((context) -> {
+					context.publishEvent(new ApplicationStartedEvent(new SpringApplication(), null,
+							context.getSourceApplicationContext(), Duration.ofMillis(2500)));
+					context.publishEvent(new ApplicationReadyEvent(new SpringApplication(), null,
+							context.getSourceApplicationContext(), Duration.ofMillis(3000)));
+					SimpleMeterRegistry registry = context.getBean(SimpleMeterRegistry.class);
+					assertThat(registry.find("application.started.time").timeGauge()).isNull();
+					assertThat(registry.find("application.ready.time").timeGauge()).isNull();
+				});
+	}
+
+	@Test
+	void customStartupTimeMetricsAreRespected() {
+		this.contextRunner.withUserConfiguration(CustomStartupTimeMetricsConfiguration.class)
+				.run((context) -> assertThat(context).hasSingleBean(StartupTimeMetrics.class)
+						.hasBean("customStartTimeMetrics"));
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class CustomStartupTimeMetricsConfiguration {
+
+		@Bean
+		StartupTimeMetrics customStartTimeMetrics() {
+			return new StartupTimeMetrics(new SimpleMeterRegistry(), Tags.empty(), "myapp.started", "myapp.ready");
+		}
+
+	}
+
+}

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/web/jetty/JettyMetricsAutoConfigurationTests.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.actuate.autoconfigure.metrics.web.jetty;
 
+import java.time.Duration;
+
 import io.micrometer.core.instrument.MeterRegistry;
 import io.micrometer.core.instrument.Tags;
 import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
@@ -58,7 +60,7 @@ class JettyMetricsAutoConfigurationTests {
 				.withUserConfiguration(ServletWebServerConfiguration.class, MeterRegistryConfiguration.class)
 				.run((context) -> {
 					context.publishEvent(new ApplicationStartedEvent(new SpringApplication(), null,
-							context.getSourceApplicationContext()));
+							context.getSourceApplicationContext(), Duration.ZERO));
 					assertThat(context).hasSingleBean(JettyServerThreadPoolMetricsBinder.class);
 					SimpleMeterRegistry registry = context.getBean(SimpleMeterRegistry.class);
 					assertThat(registry.find("jetty.threads.config.min").meter()).isNotNull();
@@ -73,7 +75,7 @@ class JettyMetricsAutoConfigurationTests {
 				.withUserConfiguration(ReactiveWebServerConfiguration.class, MeterRegistryConfiguration.class)
 				.run((context) -> {
 					context.publishEvent(new ApplicationStartedEvent(new SpringApplication(), null,
-							context.getSourceApplicationContext()));
+							context.getSourceApplicationContext(), Duration.ZERO));
 					SimpleMeterRegistry registry = context.getBean(SimpleMeterRegistry.class);
 					assertThat(registry.find("jetty.threads.config.min").meter()).isNotNull();
 				});
@@ -95,7 +97,7 @@ class JettyMetricsAutoConfigurationTests {
 				.withUserConfiguration(ServletWebServerConfiguration.class, MeterRegistryConfiguration.class)
 				.run((context) -> {
 					context.publishEvent(new ApplicationStartedEvent(new SpringApplication(), null,
-							context.getSourceApplicationContext()));
+							context.getSourceApplicationContext(), Duration.ZERO));
 					assertThat(context).hasSingleBean(JettyConnectionMetricsBinder.class);
 					SimpleMeterRegistry registry = context.getBean(SimpleMeterRegistry.class);
 					assertThat(registry.find("jetty.connections.messages.in").meter()).isNotNull();
@@ -110,7 +112,7 @@ class JettyMetricsAutoConfigurationTests {
 				.withUserConfiguration(ReactiveWebServerConfiguration.class, MeterRegistryConfiguration.class)
 				.run((context) -> {
 					context.publishEvent(new ApplicationStartedEvent(new SpringApplication(), null,
-							context.getSourceApplicationContext()));
+							context.getSourceApplicationContext(), Duration.ZERO));
 					SimpleMeterRegistry registry = context.getBean(SimpleMeterRegistry.class);
 					assertThat(registry.find("jetty.connections.messages.in").meter()).isNotNull();
 				});
@@ -125,7 +127,7 @@ class JettyMetricsAutoConfigurationTests {
 						MeterRegistryConfiguration.class)
 				.run((context) -> {
 					context.publishEvent(new ApplicationStartedEvent(new SpringApplication(), null,
-							context.getSourceApplicationContext()));
+							context.getSourceApplicationContext(), Duration.ZERO));
 					assertThat(context).hasSingleBean(JettyConnectionMetricsBinder.class)
 							.hasBean("customJettyConnectionMetricsBinder");
 					SimpleMeterRegistry registry = context.getBean(SimpleMeterRegistry.class);
@@ -144,7 +146,7 @@ class JettyMetricsAutoConfigurationTests {
 						"server.ssl.key-store-password: secret", "server.ssl.key-password: password")
 				.run((context) -> {
 					context.publishEvent(new ApplicationStartedEvent(new SpringApplication(), null,
-							context.getSourceApplicationContext()));
+							context.getSourceApplicationContext(), Duration.ZERO));
 					assertThat(context).hasSingleBean(JettySslHandshakeMetricsBinder.class);
 					SimpleMeterRegistry registry = context.getBean(SimpleMeterRegistry.class);
 					assertThat(registry.find("jetty.ssl.handshakes").meter()).isNotNull();
@@ -161,7 +163,7 @@ class JettyMetricsAutoConfigurationTests {
 						"server.ssl.key-store-password: secret", "server.ssl.key-password: password")
 				.run((context) -> {
 					context.publishEvent(new ApplicationStartedEvent(new SpringApplication(), null,
-							context.getSourceApplicationContext()));
+							context.getSourceApplicationContext(), Duration.ZERO));
 					SimpleMeterRegistry registry = context.getBean(SimpleMeterRegistry.class);
 					assertThat(registry.find("jetty.ssl.handshakes").meter()).isNotNull();
 				});
@@ -178,7 +180,7 @@ class JettyMetricsAutoConfigurationTests {
 						"server.ssl.key-store-password: secret", "server.ssl.key-password: password")
 				.run((context) -> {
 					context.publishEvent(new ApplicationStartedEvent(new SpringApplication(), null,
-							context.getSourceApplicationContext()));
+							context.getSourceApplicationContext(), Duration.ZERO));
 					assertThat(context).hasSingleBean(JettySslHandshakeMetricsBinder.class)
 							.hasBean("customJettySslHandshakeMetricsBinder");
 					SimpleMeterRegistry registry = context.getBean(SimpleMeterRegistry.class);

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/web/tomcat/TomcatMetricsAutoConfigurationTests.java

@@ -16,6 +16,7 @@
 
 package org.springframework.boot.actuate.autoconfigure.metrics.web.tomcat;
 
+import java.time.Duration;
 import java.util.Collections;
 import java.util.concurrent.atomic.AtomicInteger;
 
@@ -62,7 +63,7 @@ class TomcatMetricsAutoConfigurationTests {
 				.withUserConfiguration(ServletWebServerConfiguration.class, MeterRegistryConfiguration.class)
 				.withPropertyValues("server.tomcat.mbeanregistry.enabled=true").run((context) -> {
 					context.publishEvent(new ApplicationStartedEvent(new SpringApplication(), null,
-							context.getSourceApplicationContext()));
+							context.getSourceApplicationContext(), Duration.ZERO));
 					assertThat(context).hasSingleBean(TomcatMetricsBinder.class);
 					SimpleMeterRegistry registry = context.getBean(SimpleMeterRegistry.class);
 					assertThat(registry.find("tomcat.sessions.active.max").meter()).isNotNull();
@@ -79,7 +80,7 @@ class TomcatMetricsAutoConfigurationTests {
 				.withUserConfiguration(ReactiveWebServerConfiguration.class, MeterRegistryConfiguration.class)
 				.withPropertyValues("server.tomcat.mbeanregistry.enabled=true").run((context) -> {
 					context.publishEvent(new ApplicationStartedEvent(new SpringApplication(), null,
-							context.getSourceApplicationContext()));
+							context.getSourceApplicationContext(), Duration.ZERO));
 					SimpleMeterRegistry registry = context.getBean(SimpleMeterRegistry.class);
 					assertThat(registry.find("tomcat.sessions.active.max").meter()).isNotNull();
 					assertThat(registry.find("tomcat.threads.current").meter()).isNotNull();

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/startup/StartupTimeMetrics.java

@@ -0,0 +1,109 @@
+/*
+ * Copyright 2012-2021 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.startup;
+
+import java.util.Collections;
+import java.util.concurrent.TimeUnit;
+
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.Tag;
+import io.micrometer.core.instrument.Tags;
+import io.micrometer.core.instrument.TimeGauge;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.context.event.ApplicationReadyEvent;
+import org.springframework.boot.context.event.ApplicationStartedEvent;
+import org.springframework.context.ApplicationEvent;
+import org.springframework.context.event.SmartApplicationListener;
+
+/**
+ * Binds application startup metrics in response to {@link ApplicationStartedEvent} and
+ * {@link ApplicationReadyEvent}.
+ *
+ * @author Chris Bono
+ * @since 2.6.0
+ */
+public class StartupTimeMetrics implements SmartApplicationListener {
+
+	private final MeterRegistry meterRegistry;
+
+	private final String applicationStartedTimeMetricName;
+
+	private final String applicationReadyTimeMetricName;
+
+	private final Iterable<Tag> tags;
+
+	public StartupTimeMetrics(MeterRegistry meterRegistry) {
+		this(meterRegistry, Collections.emptyList(), "application.started.time", "application.ready.time");
+	}
+
+	public StartupTimeMetrics(MeterRegistry meterRegistry, Iterable<Tag> tags, String applicationStartedTimeMetricName,
+			String applicationReadyTimeMetricName) {
+		this.meterRegistry = meterRegistry;
+		this.tags = (tags != null) ? tags : Collections.emptyList();
+		this.applicationStartedTimeMetricName = applicationStartedTimeMetricName;
+		this.applicationReadyTimeMetricName = applicationReadyTimeMetricName;
+	}
+
+	@Override
+	public boolean supportsEventType(Class<? extends ApplicationEvent> eventType) {
+		return ApplicationStartedEvent.class.isAssignableFrom(eventType)
+				|| ApplicationReadyEvent.class.isAssignableFrom(eventType);
+	}
+
+	@Override
+	public void onApplicationEvent(ApplicationEvent event) {
+		if (event instanceof ApplicationStartedEvent) {
+			onApplicationStarted((ApplicationStartedEvent) event);
+		}
+		if (event instanceof ApplicationReadyEvent) {
+			onApplicationReady((ApplicationReadyEvent) event);
+		}
+	}
+
+	private void onApplicationStarted(ApplicationStartedEvent event) {
+		if (event.getStartupTime() == null) {
+			return;
+		}
+		TimeGauge
+				.builder(this.applicationStartedTimeMetricName, () -> event.getStartupTime().toMillis(),
+						TimeUnit.MILLISECONDS)
+				.tags(maybeDcorateTagsWithApplicationInfo(event.getSpringApplication()))
+				.description("Time taken (ms) to start the application").register(this.meterRegistry);
+	}
+
+	private void onApplicationReady(ApplicationReadyEvent event) {
+		if (event.getStartupTime() == null) {
+			return;
+		}
+		TimeGauge
+				.builder(this.applicationReadyTimeMetricName, () -> event.getStartupTime().toMillis(),
+						TimeUnit.MILLISECONDS)
+				.tags(maybeDcorateTagsWithApplicationInfo(event.getSpringApplication()))
+				.description("Time taken (ms) for the application to be ready to serve requests")
+				.register(this.meterRegistry);
+	}
+
+	private Iterable<Tag> maybeDcorateTagsWithApplicationInfo(SpringApplication springApplication) {
+		Class<?> mainClass = springApplication.getMainApplicationClass();
+		if (mainClass == null) {
+			return this.tags;
+		}
+		return Tags.concat(this.tags, "main-application-class", mainClass.getName());
+	}
+
+}

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/startup/package-info.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2012-2021 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.
+ */
+
+/**
+ * Actuator support for startup metrics.
+ */
+package org.springframework.boot.actuate.metrics.startup;

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/startup/StartupTimeMetricsTests.java

@@ -0,0 +1,121 @@
+/*
+ * Copyright 2012-2021 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.startup;
+
+import java.time.Duration;
+import java.util.concurrent.TimeUnit;
+
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.Tags;
+import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.context.event.ApplicationReadyEvent;
+import org.springframework.boot.context.event.ApplicationStartedEvent;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests for {@link StartupTimeMetrics}.
+ *
+ * @author Chris Bono
+ */
+class StartupTimeMetricsTests {
+
+	private static final long APP_STARTED_TIME_MS = 2500;
+
+	private static final long APP_RUNNING_TIME_MS = 2900;
+
+	private MeterRegistry registry;
+
+	private StartupTimeMetrics metrics;
+
+	@BeforeEach
+	void prepareUnit() {
+		this.registry = new SimpleMeterRegistry();
+		this.metrics = new StartupTimeMetrics(this.registry);
+	}
+
+	@Test
+	void metricsRecordedWithoutCustomTags() {
+		this.metrics.onApplicationEvent(applicationStartedEvent(APP_STARTED_TIME_MS));
+		this.metrics.onApplicationEvent(applicationReadyEvent(APP_RUNNING_TIME_MS));
+		assertMetricExistsWithValue("application.started.time", APP_STARTED_TIME_MS);
+		assertMetricExistsWithValue("application.ready.time", APP_RUNNING_TIME_MS);
+	}
+
+	@Test
+	void metricsRecordedWithCustomTagsAndMetricNames() {
+		Tags tags = Tags.of("foo", "bar");
+		this.metrics = new StartupTimeMetrics(this.registry, tags, "m1", "m2");
+		this.metrics.onApplicationEvent(applicationStartedEvent(APP_STARTED_TIME_MS));
+		this.metrics.onApplicationEvent(applicationReadyEvent(APP_RUNNING_TIME_MS));
+		assertMetricExistsWithCustomTagsAndValue("m1", tags, APP_STARTED_TIME_MS);
+		assertMetricExistsWithCustomTagsAndValue("m2", tags, APP_RUNNING_TIME_MS);
+	}
+
+	@Test
+	void metricsRecordedWithoutMainAppClassTagWhenMainAppClassNotAvailable() {
+		this.metrics.onApplicationEvent(applicationStartedEvent(APP_STARTED_TIME_MS));
+		this.metrics.onApplicationEvent(applicationReadyEvent(APP_RUNNING_TIME_MS));
+		assertThat(this.registry.find("application.started.time").timeGauge()).isNotNull();
+		assertThat(this.registry.find("application.ready.time").timeGauge()).isNotNull();
+	}
+
+	@Test
+	void metricsNotRecordedWhenStartupTimeNotAvailable() {
+		this.metrics.onApplicationEvent(applicationStartedEvent(null));
+		this.metrics.onApplicationEvent(applicationReadyEvent(null));
+		assertThat(this.registry.find("application.started.time").timeGauge()).isNull();
+		assertThat(this.registry.find("application.ready.time").timeGauge()).isNull();
+	}
+
+	private ApplicationStartedEvent applicationStartedEvent(Long startupTimeMs) {
+		SpringApplication application = mock(SpringApplication.class);
+		doReturn(TestMainApplication.class).when(application).getMainApplicationClass();
+		return new ApplicationStartedEvent(application, null, null,
+				(startupTimeMs != null) ? Duration.ofMillis(startupTimeMs) : null);
+	}
+
+	private ApplicationReadyEvent applicationReadyEvent(Long startupTimeMs) {
+		SpringApplication application = mock(SpringApplication.class);
+		doReturn(TestMainApplication.class).when(application).getMainApplicationClass();
+		return new ApplicationReadyEvent(application, null, null,
+				(startupTimeMs != null) ? Duration.ofMillis(startupTimeMs) : null);
+	}
+
+	private void assertMetricExistsWithValue(String metricName, double expectedValueInMillis) {
+		assertMetricExistsWithCustomTagsAndValue(metricName, Tags.empty(), expectedValueInMillis);
+	}
+
+	private void assertMetricExistsWithCustomTagsAndValue(String metricName, Tags expectedCustomTags,
+			double expectedValueInMillis) {
+		assertThat(this.registry.find(metricName)
+				.tags(Tags.concat(expectedCustomTags, "main-application-class", TestMainApplication.class.getName()))
+				.timeGauge()).isNotNull().extracting((m) -> m.value(TimeUnit.MILLISECONDS))
+						.isEqualTo(expectedValueInMillis);
+	}
+
+	static class TestMainApplication {
+
+	}
+
+}

spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/restart/RestartApplicationListenerTests.java

@@ -16,6 +16,7 @@
 
 package org.springframework.boot.devtools.restart;
 
+import java.time.Duration;
 import java.util.List;
 
 import org.junit.jupiter.api.AfterEach;
@@ -110,7 +111,7 @@ class RestartApplicationListenerTests {
 			listener.onApplicationEvent(new ApplicationFailedEvent(application, ARGS, context, new RuntimeException()));
 		}
 		else {
-			listener.onApplicationEvent(new ApplicationReadyEvent(application, ARGS, context));
+			listener.onApplicationEvent(new ApplicationReadyEvent(application, ARGS, context, Duration.ZERO));
 		}
 	}
 

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/SpringApplication.java

@@ -17,6 +17,7 @@
 package org.springframework.boot;
 
 import java.lang.reflect.Constructor;
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -150,6 +151,7 @@ import org.springframework.util.StringUtils;
  * @author Madhura Bhave
  * @author Brian Clozel
  * @author Ethan Rubinson
+ * @author Chris Bono
  * @since 1.0.0
  * @see #run(Class, String[])
  * @see #run(Class[], String[])
@@ -285,7 +287,7 @@ public class SpringApplication {
 	 */
 	public ConfigurableApplicationContext run(String... args) {
 		StopWatch stopWatch = new StopWatch();
-		stopWatch.start();
+		stopWatch.start("applicationStarted");
 		DefaultBootstrapContext bootstrapContext = createBootstrapContext();
 		ConfigurableApplicationContext context = null;
 		configureHeadlessProperty();
@@ -302,10 +304,11 @@ public class SpringApplication {
 			refreshContext(context);
 			afterRefresh(context, applicationArguments);
 			stopWatch.stop();
+			stopWatch.start("applicationReady");
 			if (this.logStartupInfo) {
 				new StartupInfoLogger(this.mainApplicationClass).logStarted(getApplicationLog(), stopWatch);
 			}
-			listeners.started(context);
+			listeners.started(context, Duration.ofMillis(stopWatch.getTotalTimeMillis()));
 			callRunners(context, applicationArguments);
 		}
 		catch (Throwable ex) {
@@ -314,7 +317,8 @@ public class SpringApplication {
 		}
 
 		try {
-			listeners.running(context);
+			stopWatch.stop();
+			listeners.running(context, Duration.ofMillis(stopWatch.getTotalTimeMillis()));
 		}
 		catch (Throwable ex) {
 			handleRunFailure(context, ex, null);

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/SpringApplicationRunListener.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot;
 
+import java.time.Duration;
+
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.core.env.ConfigurableEnvironment;
@@ -31,6 +33,7 @@ import org.springframework.core.io.support.SpringFactoriesLoader;
  * @author Phillip Webb
  * @author Dave Syer
  * @author Andy Wilkinson
+ * @author Chris Bono
  * @since 1.0.0
  */
 public interface SpringApplicationRunListener {
@@ -75,20 +78,52 @@ public interface SpringApplicationRunListener {
 	 * ApplicationRunners} have not been called.
 	 * @param context the application context.
 	 * @since 2.0.0
+	 * @deprecated since 2.6.0 for removal in 2.8.0 in favour of
+	 * {@link #started(ConfigurableApplicationContext, Duration)}
 	 */
+	@Deprecated
 	default void started(ConfigurableApplicationContext context) {
 	}
 
+	/**
+	 * The context has been refreshed and the application has started but
+	 * {@link CommandLineRunner CommandLineRunners} and {@link ApplicationRunner
+	 * ApplicationRunners} have not been called.
+	 * @param context the application context.
+	 * @param startupTime the time taken to start the application or {@code null} if
+	 * unknown
+	 * @since 2.0.0
+	 */
+	default void started(ConfigurableApplicationContext context, Duration startupTime) {
+		started(context);
+	}
+
 	/**
 	 * Called immediately before the run method finishes, when the application context has
 	 * been refreshed and all {@link CommandLineRunner CommandLineRunners} and
 	 * {@link ApplicationRunner ApplicationRunners} have been called.
 	 * @param context the application context.
+	 * @deprecated since 2.6.0 for removal in 2.8.0 in favour of
+	 * {@link #running(ConfigurableApplicationContext, Duration)}
 	 * @since 2.0.0
 	 */
+	@Deprecated
 	default void running(ConfigurableApplicationContext context) {
 	}
 
+	/**
+	 * Called immediately before the run method finishes, when the application context has
+	 * been refreshed and all {@link CommandLineRunner CommandLineRunners} and
+	 * {@link ApplicationRunner ApplicationRunners} have been called.
+	 * @param context the application context.
+	 * @param startupTime the time taken for the application to be ready to service
+	 * requests or {@code null} if unknown
+	 * @since 2.6.0
+	 */
+	default void running(ConfigurableApplicationContext context, Duration startupTime) {
+		running(context);
+	}
+
 	/**
 	 * Called when a failure occurs when running the application.
 	 * @param context the application context or {@code null} if a failure occurred before

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/SpringApplicationRunListeners.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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 +16,7 @@
 
 package org.springframework.boot;
 
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
@@ -33,6 +34,8 @@ import org.springframework.util.ReflectionUtils;
  * A collection of {@link SpringApplicationRunListener}.
  *
  * @author Phillip Webb
+ * @author Andy Wilkinson
+ * @author Chris Bono
  */
 class SpringApplicationRunListeners {
 
@@ -71,12 +74,12 @@ class SpringApplicationRunListeners {
 		doWithListeners("spring.boot.application.context-loaded", (listener) -> listener.contextLoaded(context));
 	}
 
-	void started(ConfigurableApplicationContext context) {
-		doWithListeners("spring.boot.application.started", (listener) -> listener.started(context));
+	void started(ConfigurableApplicationContext context, Duration startupTime) {
+		doWithListeners("spring.boot.application.started", (listener) -> listener.started(context, startupTime));
 	}
 
-	void running(ConfigurableApplicationContext context) {
-		doWithListeners("spring.boot.application.running", (listener) -> listener.running(context));
+	void running(ConfigurableApplicationContext context, Duration startupTime) {
+		doWithListeners("spring.boot.application.running", (listener) -> listener.running(context, startupTime));
 	}
 
 	void failed(ConfigurableApplicationContext context, Throwable exception) {

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/event/ApplicationReadyEvent.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2021 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 +16,8 @@
 
 package org.springframework.boot.context.event;
 
+import java.time.Duration;
+
 import org.springframework.boot.SpringApplication;
 import org.springframework.context.ConfigurableApplicationContext;
 
@@ -26,6 +28,7 @@ import org.springframework.context.ConfigurableApplicationContext;
  * have been completed by then.
  *
  * @author Stephane Nicoll
+ * @author Chris Bono
  * @since 1.3.0
  * @see ApplicationFailedEvent
  */
@@ -34,15 +37,32 @@ public class ApplicationReadyEvent extends SpringApplicationEvent {
 
 	private final ConfigurableApplicationContext context;
 
+	private final Duration startupTime;
+
 	/**
 	 * Create a new {@link ApplicationReadyEvent} instance.
 	 * @param application the current application
 	 * @param args the arguments the application is running with
 	 * @param context the context that was being created
+	 * @deprecated since 2.6.0 for removal in 2.8.0 in favor of
+	 * {@link #ApplicationReadyEvent(SpringApplication, String[], ConfigurableApplicationContext, Duration)}
 	 */
 	public ApplicationReadyEvent(SpringApplication application, String[] args, ConfigurableApplicationContext context) {
+		this(application, args, context, null);
+	}
+
+	/**
+	 * Create a new {@link ApplicationReadyEvent} instance.
+	 * @param application the current application
+	 * @param args the arguments the application is running with
+	 * @param context the context that was being created
+	 * @param startupTime the time taken to get the application ready to service requests
+	 */
+	public ApplicationReadyEvent(SpringApplication application, String[] args, ConfigurableApplicationContext context,
+			Duration startupTime) {
 		super(application, args);
 		this.context = context;
+		this.startupTime = startupTime;
 	}
 
 	/**
@@ -53,4 +73,12 @@ public class ApplicationReadyEvent extends SpringApplicationEvent {
 		return this.context;
 	}
 
+	/**
+	 * Return the time taken for the application to be ready to service requests.
+	 * @return the startup time
+	 */
+	public Duration getStartupTime() {
+		return this.startupTime;
+	}
+
 }

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/event/ApplicationStartedEvent.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.context.event;
 
+import java.time.Duration;
+
 import org.springframework.boot.ApplicationRunner;
 import org.springframework.boot.CommandLineRunner;
 import org.springframework.boot.SpringApplication;
@@ -34,16 +36,34 @@ public class ApplicationStartedEvent extends SpringApplicationEvent {
 
 	private final ConfigurableApplicationContext context;
 
+	private final Duration startupTime;
+
 	/**
 	 * Create a new {@link ApplicationStartedEvent} instance.
 	 * @param application the current application
 	 * @param args the arguments the application is running with
 	 * @param context the context that was being created
+	 * @deprecated since 2.6.0 for removal in 2.8.0 in favor of
+	 * {@link #ApplicationStartedEvent(SpringApplication, String[], ConfigurableApplicationContext, Duration)}
 	 */
+	@Deprecated
 	public ApplicationStartedEvent(SpringApplication application, String[] args,
 			ConfigurableApplicationContext context) {
+		this(application, args, context, null);
+	}
+
+	/**
+	 * Create a new {@link ApplicationStartedEvent} instance.
+	 * @param application the current application
+	 * @param args the arguments the application is running with
+	 * @param context the context that was being created
+	 * @param startupTime the time taken to start the application
+	 */
+	public ApplicationStartedEvent(SpringApplication application, String[] args, ConfigurableApplicationContext context,
+			Duration startupTime) {
 		super(application, args);
 		this.context = context;
+		this.startupTime = startupTime;
 	}
 
 	/**
@@ -54,4 +74,12 @@ public class ApplicationStartedEvent extends SpringApplicationEvent {
 		return this.context;
 	}
 
+	/**
+	 * Return the time taken to start the application.
+	 * @return the startup time
+	 */
+	public Duration getStartupTime() {
+		return this.startupTime;
+	}
+
 }

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/event/EventPublishingRunListener.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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 +16,8 @@
 
 package org.springframework.boot.context.event;
 
+import java.time.Duration;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
@@ -46,6 +48,7 @@ import org.springframework.util.ErrorHandler;
  * @author Andy Wilkinson
  * @author Artsiom Yudovin
  * @author Brian Clozel
+ * @author Chris Bono
  * @since 1.0.0
  */
 public class EventPublishingRunListener implements SpringApplicationRunListener, Ordered {
@@ -101,14 +104,26 @@ public class EventPublishingRunListener implements SpringApplicationRunListener,
 	}
 
 	@Override
+	@Deprecated
 	public void started(ConfigurableApplicationContext context) {
-		context.publishEvent(new ApplicationStartedEvent(this.application, this.args, context));
+		started(context, null);
+	}
+
+	@Override
+	public void started(ConfigurableApplicationContext context, Duration startupTime) {
+		context.publishEvent(new ApplicationStartedEvent(this.application, this.args, context, startupTime));
 		AvailabilityChangeEvent.publish(context, LivenessState.CORRECT);
 	}
 
 	@Override
+	@Deprecated
 	public void running(ConfigurableApplicationContext context) {
-		context.publishEvent(new ApplicationReadyEvent(this.application, this.args, context));
+		running(context, null);
+	}
+
+	@Override
+	public void running(ConfigurableApplicationContext context, Duration startupTime) {
+		context.publishEvent(new ApplicationReadyEvent(this.application, this.args, context, startupTime));
 		AvailabilityChangeEvent.publish(context, ReadinessState.ACCEPTING_TRAFFIC);
 	}
 

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/SpringApplicationTests.java

@@ -149,6 +149,7 @@ import static org.mockito.Mockito.verifyNoMoreInteractions;
  * @author Artsiom Yudovin
  * @author Marten Deinum
  * @author Nguyen Bao Sach
+ * @author Chris Bono
  */
 @ExtendWith(OutputCaptureExtension.class)
 class SpringApplicationTests {
@@ -417,6 +418,42 @@ class SpringApplicationTests {
 		inOrder.verifyNoMoreInteractions();
 	}
 
+	@Test
+	void applicationStartedEventHasStartupTime() {
+		SpringApplication application = new SpringApplication(ExampleConfig.class);
+		application.setWebApplicationType(WebApplicationType.NONE);
+		final AtomicReference<ApplicationStartedEvent> reference = new AtomicReference<>();
+		class ApplicationStartedEventListener implements ApplicationListener<ApplicationStartedEvent> {
+
+			@Override
+			public void onApplicationEvent(ApplicationStartedEvent event) {
+				reference.set(event);
+			}
+
+		}
+		application.addListeners(new ApplicationStartedEventListener());
+		this.context = application.run();
+		assertThat(reference.get()).isNotNull().extracting(ApplicationStartedEvent::getStartupTime).isNotNull();
+	}
+
+	@Test
+	void applicationReadyEventHasStartupTime() {
+		SpringApplication application = new SpringApplication(ExampleConfig.class);
+		application.setWebApplicationType(WebApplicationType.NONE);
+		final AtomicReference<ApplicationReadyEvent> reference = new AtomicReference<>();
+		class ApplicationReadyEventListener implements ApplicationListener<ApplicationReadyEvent> {
+
+			@Override
+			public void onApplicationEvent(ApplicationReadyEvent event) {
+				reference.set(event);
+			}
+
+		}
+		application.addListeners(new ApplicationReadyEventListener());
+		this.context = application.run();
+		assertThat(reference.get()).isNotNull().extracting(ApplicationReadyEvent::getStartupTime).isNotNull();
+	}
+
 	@Test
 	void defaultApplicationContext() {
 		SpringApplication application = new SpringApplication(ExampleConfig.class);

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/admin/SpringApplicationAdminMXBeanRegistrarTests.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.admin;
 
 import java.lang.management.ManagementFactory;
+import java.time.Duration;
 
 import javax.management.InstanceNotFoundException;
 import javax.management.MBeanServer;
@@ -88,10 +89,11 @@ class SpringApplicationAdminMXBeanRegistrarTests {
 		SpringApplicationAdminMXBeanRegistrar registrar = new SpringApplicationAdminMXBeanRegistrar(OBJECT_NAME);
 		ConfigurableApplicationContext context = mock(ConfigurableApplicationContext.class);
 		registrar.setApplicationContext(context);
-		registrar.onApplicationReadyEvent(
-				new ApplicationReadyEvent(new SpringApplication(), null, mock(ConfigurableApplicationContext.class)));
+		registrar.onApplicationReadyEvent(new ApplicationReadyEvent(new SpringApplication(), null,
+				mock(ConfigurableApplicationContext.class), Duration.ZERO));
 		assertThat(isApplicationReady(registrar)).isFalse();
-		registrar.onApplicationReadyEvent(new ApplicationReadyEvent(new SpringApplication(), null, context));
+		registrar.onApplicationReadyEvent(
+				new ApplicationReadyEvent(new SpringApplication(), null, context, Duration.ZERO));
 		assertThat(isApplicationReady(registrar)).isTrue();
 	}
 

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/ApplicationPidFileWriterTests.java

@@ -18,6 +18,7 @@ package org.springframework.boot.context;
 
 import java.io.File;
 import java.io.IOException;
+import java.time.Duration;
 import java.util.function.Consumer;
 
 import org.junit.jupiter.api.AfterEach;
@@ -187,7 +188,7 @@ class ApplicationPidFileWriterTests {
 		ConfigurableEnvironment environment = createEnvironment(propName, propValue);
 		ConfigurableApplicationContext context = mock(ConfigurableApplicationContext.class);
 		given(context.getEnvironment()).willReturn(environment);
-		return new ApplicationReadyEvent(new SpringApplication(), new String[] {}, context);
+		return new ApplicationReadyEvent(new SpringApplication(), new String[] {}, context, Duration.ZERO);
 	}
 
 	private ConfigurableEnvironment createEnvironment(String propName, String propValue) {

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/event/EventPublishingRunListenerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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 +16,7 @@
 
 package org.springframework.boot.context.event;
 
+import java.time.Duration;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -72,9 +73,9 @@ class EventPublishingRunListenerTests {
 		this.runListener.contextLoaded(context);
 		checkApplicationEvents(ApplicationPreparedEvent.class);
 		context.refresh();
-		this.runListener.started(context);
+		this.runListener.started(context, Duration.ZERO);
 		checkApplicationEvents(ApplicationStartedEvent.class, AvailabilityChangeEvent.class);
-		this.runListener.running(context);
+		this.runListener.running(context, Duration.ZERO);
 		checkApplicationEvents(ApplicationReadyEvent.class, AvailabilityChangeEvent.class);
 	}