Health indicators based on Service Level Objectives

spring-boot-project/spring-boot-actuator-autoconfigure/build.gradle

@@ -53,6 +53,7 @@ dependencies {
 	optional("io.micrometer:micrometer-registry-influx")
 	optional("io.micrometer:micrometer-registry-jmx")
 	optional("io.micrometer:micrometer-registry-kairos")
+	optional("io.micrometer:micrometer-registry-health")
 	optional("io.micrometer:micrometer-registry-new-relic")
 	optional("io.micrometer:micrometer-registry-prometheus")
 	optional("io.micrometer:micrometer-registry-stackdriver")

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/export/health/HealthMetricsExportAutoConfiguration.java

@@ -0,0 +1,150 @@
+/*
+ * Copyright 2012-2020 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.export.health;
+
+import java.util.Arrays;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import io.micrometer.core.instrument.Clock;
+import io.micrometer.core.instrument.Meter;
+import io.micrometer.core.instrument.Tag;
+import io.micrometer.core.instrument.binder.BaseUnits;
+import io.micrometer.core.instrument.config.NamingConvention;
+import io.micrometer.health.HealthConfig;
+import io.micrometer.health.HealthMeterRegistry;
+import io.micrometer.health.ServiceLevelObjective;
+import io.micrometer.health.objectives.JvmServiceLevelObjectives;
+import io.micrometer.health.objectives.OperatingSystemServiceLevelObjectives;
+
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.boot.actuate.autoconfigure.metrics.CompositeMeterRegistryAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.metrics.MetricsAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.metrics.export.simple.SimpleMetricsExportAutoConfiguration;
+import org.springframework.boot.actuate.health.AbstractHealthIndicator;
+import org.springframework.boot.actuate.health.CompositeHealthContributor;
+import org.springframework.boot.actuate.health.Health;
+import org.springframework.boot.actuate.health.HealthContributor;
+import org.springframework.boot.actuate.health.Status;
+import org.springframework.boot.autoconfigure.AutoConfigureAfter;
+import org.springframework.boot.autoconfigure.AutoConfigureBefore;
+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.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.support.GenericApplicationContext;
+
+/**
+ * {@link EnableAutoConfiguration Auto-configuration} for building health indicators based
+ * on service level objectives.
+ *
+ * @author Jon Schneider
+ * @since 2.4.0
+ */
+@Configuration(proxyBeanMethods = false)
+@AutoConfigureBefore({ CompositeMeterRegistryAutoConfiguration.class, SimpleMetricsExportAutoConfiguration.class })
+@AutoConfigureAfter(MetricsAutoConfiguration.class)
+@ConditionalOnBean(Clock.class)
+@ConditionalOnClass(HealthMeterRegistry.class)
+@ConditionalOnProperty(prefix = "management.metrics.export.health", name = "enabled", havingValue = "true",
+		matchIfMissing = true)
+@EnableConfigurationProperties(HealthProperties.class)
+public class HealthMetricsExportAutoConfiguration {
+
+	private final NamingConvention camelCasedHealthIndicatorNames = NamingConvention.camelCase;
+
+	private final HealthProperties properties;
+
+	public HealthMetricsExportAutoConfiguration(HealthProperties properties) {
+		this.properties = properties;
+	}
+
+	@Bean
+	@ConditionalOnMissingBean
+	public HealthConfig healthConfig() {
+		return new HealthPropertiesConfigAdapter(this.properties);
+	}
+
+	@Bean
+	@ConditionalOnMissingBean
+	public HealthMeterRegistry healthMeterRegistry(HealthConfig healthConfig, Clock clock,
+			ObjectProvider<ServiceLevelObjective> serviceLevelObjectives,
+			GenericApplicationContext applicationContext) {
+		HealthMeterRegistry registry = HealthMeterRegistry.builder(healthConfig).clock(clock)
+				.serviceLevelObjectives(serviceLevelObjectives.orderedStream().toArray(ServiceLevelObjective[]::new))
+				.serviceLevelObjectives(JvmServiceLevelObjectives.MEMORY)
+				.serviceLevelObjectives(OperatingSystemServiceLevelObjectives.DISK).serviceLevelObjectives(
+						this.properties.getApiErrorBudgets().entrySet().stream().map((apiErrorBudget) -> {
+							String apiEndpoints = '/' + apiErrorBudget.getKey().replace('.', '/');
+
+							return ServiceLevelObjective.build("api.error.ratio." + apiErrorBudget.getKey())
+									.failedMessage("API error ratio exceeded.").baseUnit(BaseUnits.PERCENT)
+									.tag("uri.matches", apiEndpoints + "/**").tag("error.outcome", "SERVER_ERROR")
+									.errorRatio(
+											(s) -> s.name("http.server.requests").tag("uri",
+													(uri) -> uri.startsWith(apiEndpoints)),
+											(all) -> all.tag("outcome", "SERVER_ERROR"))
+									.isLessThan(apiErrorBudget.getValue());
+						}).toArray(ServiceLevelObjective[]::new))
+				.build();
+
+		for (ServiceLevelObjective slo : registry.getServiceLevelObjectives()) {
+			applicationContext.registerBean(this.camelCasedHealthIndicatorNames.name(slo.getName(), Meter.Type.GAUGE),
+					HealthContributor.class, () -> toHealthContributor(registry, slo));
+		}
+
+		return registry;
+	}
+
+	private HealthContributor toHealthContributor(HealthMeterRegistry registry, ServiceLevelObjective slo) {
+		if (slo instanceof ServiceLevelObjective.SingleIndicator) {
+			final NamingConvention tagConvention = this.camelCasedHealthIndicatorNames;
+			return new AbstractHealthIndicator(slo.getFailedMessage()) {
+				@Override
+				protected void doHealthCheck(Health.Builder builder) {
+					ServiceLevelObjective.SingleIndicator singleIndicator = (ServiceLevelObjective.SingleIndicator) slo;
+					builder.status(slo.healthy(registry) ? Status.UP : Status.OUT_OF_SERVICE)
+							.withDetail("value", singleIndicator.getValueAsString(registry))
+							.withDetail("mustBe", singleIndicator.getTestDescription());
+
+					for (Tag tag : slo.getTags()) {
+						builder.withDetail(tagConvention.tagKey(tag.getKey()), tag.getValue());
+					}
+
+					if (slo.getBaseUnit() != null) {
+						builder.withDetail("unit", slo.getBaseUnit());
+					}
+				}
+			};
+		}
+		else {
+			ServiceLevelObjective.MultipleIndicator multipleIndicator = (ServiceLevelObjective.MultipleIndicator) slo;
+			Map<String, HealthContributor> objectiveIndicators = Arrays.stream(multipleIndicator.getObjectives())
+					.collect(
+							Collectors.toMap(
+									(indicator) -> this.camelCasedHealthIndicatorNames.name(indicator.getName(),
+											Meter.Type.GAUGE),
+									(indicator) -> toHealthContributor(registry, indicator)));
+			return CompositeHealthContributor.fromMap(objectiveIndicators);
+		}
+	}
+
+}

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/export/health/HealthProperties.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2012-2020 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.export.health;
+
+import java.time.Duration;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+/**
+ * {@link ConfigurationProperties @ConfigurationProperties} for configuring health
+ * indicators based on service level objectives.
+ *
+ * @author Jon Schneider
+ * @since 2.4.0
+ */
+@ConfigurationProperties(prefix = "management.metrics.export.health")
+public class HealthProperties {
+
+	/**
+	 * Step size (i.e. polling frequency for moving window indicators) to use.
+	 */
+	private Duration step = Duration.ofSeconds(10);
+
+	/**
+	 * Error budgets by API endpoint prefix. The value is a percentage in the range [0,1].
+	 */
+	private final Map<String, Double> apiErrorBudgets = new LinkedHashMap<>();
+
+	public Duration getStep() {
+		return this.step;
+	}
+
+	public void setStep(Duration step) {
+		this.step = step;
+	}
+
+	public Map<String, Double> getApiErrorBudgets() {
+		return this.apiErrorBudgets;
+	}
+
+}

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/metrics/export/health/HealthPropertiesConfigAdapter.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2012-2020 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.export.health;
+
+import java.time.Duration;
+
+import io.micrometer.health.HealthConfig;
+
+import org.springframework.boot.actuate.autoconfigure.metrics.export.properties.PropertiesConfigAdapter;
+
+/**
+ * Adapter to convert {@link HealthProperties} to a {@link HealthConfig}.
+ *
+ * @author Jon Schneider
+ */
+class HealthPropertiesConfigAdapter extends PropertiesConfigAdapter<HealthProperties> implements HealthConfig {
+
+	HealthPropertiesConfigAdapter(HealthProperties properties) {
+		super(properties);
+	}
+
+	@Override
+	public String prefix() {
+		return "management.metrics.export.health";
+	}
+
+	@Override
+	public String get(String k) {
+		return null;
+	}
+
+	@Override
+	public Duration step() {
+		return get(HealthProperties::getStep, HealthConfig.super::step);
+	}
+
+}

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

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2012-2020 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.
+ */
+
+/**
+ * Support for building health indicators with service level objectives.
+ */
+package org.springframework.boot.actuate.autoconfigure.metrics.export.health;