Rename Service Level Agreement to Service Level Objective

This commit harmonizes our integration of Micrometer's Service Level
objectives.

Closes gh-21076

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

@@ -20,6 +20,7 @@ import java.util.LinkedHashMap;
 import java.util.Map;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.boot.context.properties.DeprecatedConfigurationProperty;
 import org.springframework.boot.context.properties.NestedConfigurationProperty;
 
 /**
@@ -232,12 +233,12 @@ public class MetricsProperties {
 		private final Map<String, double[]> percentiles = new LinkedHashMap<>();
 
 		/**
-		 * Specific SLA boundaries for meter IDs starting-with the specified name. The
+		 * Specific Service Level Objectives boundaries for meter IDs starting-with the
-		 * longest match wins. Counters will be published for each specified boundary.
+		 * specified name. The longest match wins. Counters will be published for each
-		 * Values can be specified as a long or as a Duration value (for timer meters,
+		 * specified boundary. Values can be specified as a long or as a Duration value
-		 * defaulting to ms if no unit specified).
+		 * (for timer meters, defaulting to ms if no unit specified).
 		 */
-		private final Map<String, ServiceLevelAgreementBoundary[]> sla = new LinkedHashMap<>();
+		private final Map<String, ServiceLevelObjectiveBoundary[]> slo = new LinkedHashMap<>();
 
 		/**
 		 * Minimum value that meter IDs starting-with the specified name are expected to
@@ -261,8 +262,14 @@ public class MetricsProperties {
 			return this.percentiles;
 		}
 
-		public Map<String, ServiceLevelAgreementBoundary[]> getSla() {
+		@Deprecated
-			return this.sla;
+		@DeprecatedConfigurationProperty(replacement = "management.metrics.distribution.slo")
+		public Map<String, ServiceLevelObjectiveBoundary[]> getSla() {
+			return this.slo;
+		}
+
+		public Map<String, ServiceLevelObjectiveBoundary[]> getSlo() {
+			return this.slo;
 		}
 
 		public Map<String, String> getMinimumExpectedValue() {

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

@@ -83,7 +83,8 @@ public class PropertiesMeterFilter implements MeterFilter {
 		return DistributionStatisticConfig.builder()
 				.percentilesHistogram(lookupWithFallbackToAll(distribution.getPercentilesHistogram(), id, null))
 				.percentiles(lookupWithFallbackToAll(distribution.getPercentiles(), id, null))
-				.sla(convertSla(id.getType(), lookup(distribution.getSla(), id, null)))
+				.serviceLevelObjectives(
+						convertServiceLevelObjectives(id.getType(), lookup(distribution.getSlo(), id, null)))
 				.minimumExpectedValue(
 						convertMeterValue(id.getType(), lookup(distribution.getMinimumExpectedValue(), id, null)))
 				.maximumExpectedValue(
@@ -91,11 +92,11 @@ public class PropertiesMeterFilter implements MeterFilter {
 				.build().merge(config);
 	}
 
-	private double[] convertSla(Meter.Type meterType, ServiceLevelAgreementBoundary[] sla) {
+	private double[] convertServiceLevelObjectives(Meter.Type meterType, ServiceLevelObjectiveBoundary[] slo) {
-		if (sla == null) {
+		if (slo == null) {
 			return null;
 		}
-		double[] converted = Arrays.stream(sla).map((candidate) -> candidate.getValue(meterType))
+		double[] converted = Arrays.stream(slo).map((candidate) -> candidate.getValue(meterType))
 				.filter(Objects::nonNull).mapToDouble(Double::doubleValue).toArray();
 		return (converted.length != 0) ? converted : null;
 	}

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

@@ -22,12 +22,14 @@ import io.micrometer.core.instrument.Meter;
 
 /**
  * A service level agreement boundary for use when configuring Micrometer. Can be
- * specified as either a {@link Double} (applicable to timers and distribution summaries)
+ * specified as either a {@link Long} (applicable to timers and distribution summaries) or
- * or a {@link Duration} (applicable to only timers).
+ * a {@link Duration} (applicable to only timers).
  *
  * @author Phillip Webb
  * @since 2.0.0
+ * @deprecated as of 2.3.0 in favor of {@link ServiceLevelObjectiveBoundary}
  */
+@Deprecated
 public final class ServiceLevelAgreementBoundary {
 
 	private final MeterValue value;
@@ -42,17 +44,18 @@ public final class ServiceLevelAgreementBoundary {
 	 * @param meterType the meter type
 	 * @return the value or {@code null} if the value cannot be applied
 	 */
-	public Double getValue(Meter.Type meterType) {
+	public Long getValue(Meter.Type meterType) {
-		return this.value.getValue(meterType);
+		Double value = this.value.getValue(meterType);
+		return (value != null) ? value.longValue() : null;
 	}
 
 	/**
-	 * Return a new {@link ServiceLevelAgreementBoundary} instance for the given double
+	 * Return a new {@link ServiceLevelAgreementBoundary} instance for the given long
 	 * value.
 	 * @param value the source value
 	 * @return a {@link ServiceLevelAgreementBoundary} instance
 	 */
-	public static ServiceLevelAgreementBoundary valueOf(double value) {
+	public static ServiceLevelAgreementBoundary valueOf(long value) {
 		return new ServiceLevelAgreementBoundary(MeterValue.valueOf(value));
 	}
 

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

@@ -0,0 +1,70 @@
+/*
+ * 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;
+
+import java.time.Duration;
+
+import io.micrometer.core.instrument.Meter;
+
+/**
+ * A service level objective boundary for use when configuring Micrometer. Can be
+ * specified as either a {@link Double} (applicable to timers and distribution summaries)
+ * or a {@link Duration} (applicable to only timers).
+ *
+ * @author Phillip Webb
+ * @author Stephane Nicoll
+ * @since 2.3.0
+ */
+public final class ServiceLevelObjectiveBoundary {
+
+	private final MeterValue value;
+
+	ServiceLevelObjectiveBoundary(MeterValue value) {
+		this.value = value;
+	}
+
+	/**
+	 * Return the underlying value of the SLO in form suitable to apply to the given meter
+	 * type.
+	 * @param meterType the meter type
+	 * @return the value or {@code null} if the value cannot be applied
+	 */
+	public Double getValue(Meter.Type meterType) {
+		return this.value.getValue(meterType);
+	}
+
+	/**
+	 * Return a new {@link ServiceLevelObjectiveBoundary} instance for the given double
+	 * value.
+	 * @param value the source value
+	 * @return a {@link ServiceLevelObjectiveBoundary} instance
+	 */
+	public static ServiceLevelObjectiveBoundary valueOf(double value) {
+		return new ServiceLevelObjectiveBoundary(MeterValue.valueOf(value));
+	}
+
+	/**
+	 * Return a new {@link ServiceLevelObjectiveBoundary} instance for the given String
+	 * value.
+	 * @param value the source value
+	 * @return a {@link ServiceLevelObjectiveBoundary} instance
+	 */
+	public static ServiceLevelObjectiveBoundary valueOf(String value) {
+		return new ServiceLevelObjectiveBoundary(MeterValue.valueOf(value));
+	}
+
+}

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

@@ -204,29 +204,35 @@ class PropertiesMeterFilterTests {
 	}
 
 	@Test
-	void configureWhenHasSlaShouldSetSlaToValue() {
+	@Deprecated
+	void configureWhenHasDeprecatedSlaShouldSetSlaToValue() {
 		PropertiesMeterFilter filter = new PropertiesMeterFilter(
 				createProperties("distribution.sla.spring.boot=1,2,3"));
-		assertThat(
+		assertThat(filter.configure(createMeterId("spring.boot"), DistributionStatisticConfig.DEFAULT)
-				filter.configure(createMeterId("spring.boot"), DistributionStatisticConfig.DEFAULT).getSlaBoundaries())
+				.getServiceLevelObjectiveBoundaries()).containsExactly(1000000, 2000000, 3000000);
-						.containsExactly(1000000, 2000000, 3000000);
 	}
 
 	@Test
-	void configureWhenHasHigherSlaShouldSetPercentilesToValue() {
+	void configureWhenHasSloShouldSetSloToValue() {
-		PropertiesMeterFilter filter = new PropertiesMeterFilter(createProperties("distribution.sla.spring=1,2,3"));
-		assertThat(
-				filter.configure(createMeterId("spring.boot"), DistributionStatisticConfig.DEFAULT).getSlaBoundaries())
-						.containsExactly(1000000, 2000000, 3000000);
-	}
-
-	@Test
-	void configureWhenHasHigherSlaAndLowerShouldSetSlaToHigher() {
 		PropertiesMeterFilter filter = new PropertiesMeterFilter(
-				createProperties("distribution.sla.spring=1,2,3", "distribution.sla.spring.boot=4,5,6"));
+				createProperties("distribution.slo.spring.boot=1,2,3"));
-		assertThat(
+		assertThat(filter.configure(createMeterId("spring.boot"), DistributionStatisticConfig.DEFAULT)
-				filter.configure(createMeterId("spring.boot"), DistributionStatisticConfig.DEFAULT).getSlaBoundaries())
+				.getServiceLevelObjectiveBoundaries()).containsExactly(1000000, 2000000, 3000000);
-						.containsExactly(4000000, 5000000, 6000000);
+	}
+
+	@Test
+	void configureWhenHasHigherSloShouldSetPercentilesToValue() {
+		PropertiesMeterFilter filter = new PropertiesMeterFilter(createProperties("distribution.slo.spring=1,2,3"));
+		assertThat(filter.configure(createMeterId("spring.boot"), DistributionStatisticConfig.DEFAULT)
+				.getServiceLevelObjectiveBoundaries()).containsExactly(1000000, 2000000, 3000000);
+	}
+
+	@Test
+	void configureWhenHasHigherSloAndLowerShouldSetSloToHigher() {
+		PropertiesMeterFilter filter = new PropertiesMeterFilter(
+				createProperties("distribution.slo.spring=1,2,3", "distribution.slo.spring.boot=4,5,6"));
+		assertThat(filter.configure(createMeterId("spring.boot"), DistributionStatisticConfig.DEFAULT)
+				.getServiceLevelObjectiveBoundaries()).containsExactly(4000000, 5000000, 6000000);
 	}
 
 	@Test

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

@@ -22,47 +22,47 @@ import org.junit.jupiter.api.Test;
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
- * Tests for {@link ServiceLevelAgreementBoundary}.
+ * Tests for {@link ServiceLevelObjectiveBoundary}.
  *
  * @author Phillip Webb
  * @author Stephane Nicoll
  */
-class ServiceLevelAgreementBoundaryTests {
+class ServiceLevelObjectiveBoundaryTests {
 
 	@Test
 	void getValueForTimerWhenFromLongShouldReturnMsToNanosValue() {
-		ServiceLevelAgreementBoundary sla = ServiceLevelAgreementBoundary.valueOf(123L);
+		ServiceLevelObjectiveBoundary slo = ServiceLevelObjectiveBoundary.valueOf(123L);
-		assertThat(sla.getValue(Type.TIMER)).isEqualTo(123000000);
+		assertThat(slo.getValue(Type.TIMER)).isEqualTo(123000000);
 	}
 
 	@Test
 	void getValueForTimerWhenFromNumberStringShouldMsToNanosValue() {
-		ServiceLevelAgreementBoundary sla = ServiceLevelAgreementBoundary.valueOf("123");
+		ServiceLevelObjectiveBoundary slo = ServiceLevelObjectiveBoundary.valueOf("123");
-		assertThat(sla.getValue(Type.TIMER)).isEqualTo(123000000);
+		assertThat(slo.getValue(Type.TIMER)).isEqualTo(123000000);
 	}
 
 	@Test
 	void getValueForTimerWhenFromDurationStringShouldReturnDurationNanos() {
-		ServiceLevelAgreementBoundary sla = ServiceLevelAgreementBoundary.valueOf("123ms");
+		ServiceLevelObjectiveBoundary slo = ServiceLevelObjectiveBoundary.valueOf("123ms");
-		assertThat(sla.getValue(Type.TIMER)).isEqualTo(123000000);
+		assertThat(slo.getValue(Type.TIMER)).isEqualTo(123000000);
 	}
 
 	@Test
 	void getValueForDistributionSummaryWhenFromDoubleShouldReturnDoubleValue() {
-		ServiceLevelAgreementBoundary sla = ServiceLevelAgreementBoundary.valueOf(123.42);
+		ServiceLevelObjectiveBoundary slo = ServiceLevelObjectiveBoundary.valueOf(123.42);
-		assertThat(sla.getValue(Type.DISTRIBUTION_SUMMARY)).isEqualTo(123.42);
+		assertThat(slo.getValue(Type.DISTRIBUTION_SUMMARY)).isEqualTo(123.42);
 	}
 
 	@Test
 	void getValueForDistributionSummaryWhenFromStringShouldReturnDoubleValue() {
-		ServiceLevelAgreementBoundary sla = ServiceLevelAgreementBoundary.valueOf("123.42");
+		ServiceLevelObjectiveBoundary slo = ServiceLevelObjectiveBoundary.valueOf("123.42");
-		assertThat(sla.getValue(Type.DISTRIBUTION_SUMMARY)).isEqualTo(123.42);
+		assertThat(slo.getValue(Type.DISTRIBUTION_SUMMARY)).isEqualTo(123.42);
 	}
 
 	@Test
 	void getValueForDistributionSummaryWhenFromDurationShouldReturnNull() {
-		ServiceLevelAgreementBoundary sla = ServiceLevelAgreementBoundary.valueOf("123ms");
+		ServiceLevelObjectiveBoundary slo = ServiceLevelObjectiveBoundary.valueOf("123ms");
-		assertThat(sla.getValue(Type.DISTRIBUTION_SUMMARY)).isNull();
+		assertThat(slo.getValue(Type.DISTRIBUTION_SUMMARY)).isNull();
 	}
 
 }

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

@@ -2131,8 +2131,8 @@ The following properties allow per-meter customization:
 | configprop:management.metrics.distribution.percentiles[]
 | Publish percentile values computed in your application
 
-| configprop:management.metrics.distribution.sla[]
+| configprop:management.metrics.distribution.slo[]
-| Publish a cumulative histogram with buckets defined by your SLAs.
+| Publish a cumulative histogram with buckets defined by your Service Level Objectives.
 |===
 
 For more details on concepts behind `percentiles-histogram`, `percentiles` and `sla` refer to the {micrometer-concepts-docs}#_histograms_and_percentiles["Histograms and percentiles" section] of the micrometer documentation.