Merge branch '2.3.x'

Closes gh-23908

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

@@ -122,6 +122,7 @@ dependencies {
 	testImplementation("org.apache.logging.log4j:log4j-to-slf4j")
 	testImplementation("org.aspectj:aspectjrt")
 	testImplementation("org.assertj:assertj-core")
+	testImplementation("org.awaitility:awaitility")
 	testImplementation("org.eclipse.jetty:jetty-webapp")
 	testImplementation("org.glassfish.jersey.ext:jersey-spring5")
 	testImplementation("org.glassfish.jersey.media:jersey-media-json-jackson")

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.boot.actuate.autoconfigure.metrics.test;
 
+import java.time.Duration;
 import java.util.Collections;
 import java.util.Map;
 import java.util.Set;
@@ -71,6 +72,7 @@ import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.client.RestTemplate;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.awaitility.Awaitility.waitAtMost;
 import static org.springframework.test.web.client.ExpectedCount.once;
 import static org.springframework.test.web.client.match.MockRestRequestMatchers.method;
 import static org.springframework.test.web.client.match.MockRestRequestMatchers.requestTo;
@@ -110,7 +112,9 @@ class MetricsIntegrationTests {
 	@Test
 	void requestMappingIsInstrumented() {
 		this.loopback.getForObject("/api/people", Set.class);
-		assertThat(this.registry.get("http.server.requests").timer().count()).isEqualTo(1);
+		waitAtMost(Duration.ofSeconds(5)).untilAsserted(
+				() -> assertThat(this.registry.get("http.server.requests").timer().count()).isEqualTo(1));
+
 	}
 
 	@Test