Merge remote-tracking branch 'origin/4.1.x'

# Conflicts:
#	pom.xml

pom.xml

@@ -23,7 +23,7 @@
 		<bintray.package>netflix</bintray.package>
 		<spring-cloud-commons.version>4.2.0-SNAPSHOT</spring-cloud-commons.version>
 		<spring-cloud-config.version>4.2.0-SNAPSHOT</spring-cloud-config.version>
-		<testcontainers.version>1.20.3</testcontainers.version>
+		<testcontainers.version>1.20.4</testcontainers.version>
 		<mockserverclient.version>5.15.0</mockserverclient.version>
 
 		<!-- Sonar -->

spring-cloud-netflix-eureka-server/pom.xml

@@ -98,6 +98,12 @@
             <artifactId>spring-cloud-starter</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.awaitility</groupId>
+			<artifactId>awaitility</artifactId>
+			<scope>test</scope>
+		</dependency>
+
 	</dependencies>
 	<build>
 		<resources>

spring-cloud-netflix-eureka-server/src/main/java/org/springframework/cloud/netflix/eureka/server/metrics/EurekaInstanceMetricsAutoConfiguration.java

@@ -28,11 +28,13 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.cloud.netflix.eureka.server.EurekaServerAutoConfiguration;
 import org.springframework.context.annotation.Bean;
+import org.springframework.core.task.TaskExecutor;
 
 /**
  * Auto-configuration for Eureka Instance metrics.
  *
  * @author Wonchul Heo
+ * @author Olga Maciaszek-Sharma
  * @since 4.1.2
  */
 @ConditionalOnClass(MeterRegistry.class)
@@ -51,8 +53,8 @@ class EurekaInstanceMetricsAutoConfiguration {
 	@ConditionalOnMissingBean
 	@Bean
 	public EurekaInstanceMonitor eurekaInstanceMeterBinder(MeterRegistry meterRegistry,
-			PeerAwareInstanceRegistry instanceRegistry, EurekaInstanceTagsProvider tagProvider) {
-		return new EurekaInstanceMonitor(meterRegistry, instanceRegistry, tagProvider);
+			PeerAwareInstanceRegistry instanceRegistry, EurekaInstanceTagsProvider tagProvider, TaskExecutor executor) {
+		return new EurekaInstanceMonitor(meterRegistry, instanceRegistry, tagProvider, executor);
 	}
 
 }

spring-cloud-netflix-eureka-server/src/main/java/org/springframework/cloud/netflix/eureka/server/metrics/EurekaInstanceMonitor.java

@@ -18,6 +18,7 @@ package org.springframework.cloud.netflix.eureka.server.metrics;
 
 import java.util.Map;
 import java.util.Objects;
+import java.util.concurrent.Executor;
 import java.util.stream.Collectors;
 
 import com.netflix.eureka.registry.PeerAwareInstanceRegistry;
@@ -36,6 +37,7 @@ import org.springframework.context.event.SmartApplicationListener;
  * {@link PeerAwareInstanceRegistry}.
  *
  * @author Wonchul Heo
+ * @author Olga Maciaszek-Sharma
  * @since 4.1.2
  */
 public class EurekaInstanceMonitor implements SmartApplicationListener {
@@ -46,14 +48,17 @@ public class EurekaInstanceMonitor implements SmartApplicationListener {
 
 	private final EurekaInstanceTagsProvider tagProvider;
 
+	private final Executor executor;
+
 	EurekaInstanceMonitor(MeterRegistry meterRegistry, PeerAwareInstanceRegistry instanceRegistry,
-			EurekaInstanceTagsProvider tagProvider) {
+			EurekaInstanceTagsProvider tagProvider, Executor executor) {
 		Objects.requireNonNull(meterRegistry);
 		this.instanceRegistry = Objects.requireNonNull(instanceRegistry);
 		this.tagProvider = Objects.requireNonNull(tagProvider);
 		this.eurekaInstances = MultiGauge.builder("eureka.server.instances")
 			.description("Number of application instances registered with the Eureka server.")
 			.register(meterRegistry);
+		this.executor = executor;
 	}
 
 	@Override
@@ -71,6 +76,10 @@ public class EurekaInstanceMonitor implements SmartApplicationListener {
 			.stream()
 			.flatMap(application -> application.getInstances().stream())
 			.collect(Collectors.groupingBy(tagProvider::eurekaInstanceTags, Collectors.counting()));
+		executor.execute(() -> registerMetrics(aggregatedCounts));
+	}
+
+	private void registerMetrics(Map<Tags, Long> aggregatedCounts) {
 		eurekaInstances.register(aggregatedCounts.entrySet()
 			.stream()
 			.map(entry -> MultiGauge.Row.of(entry.getKey(), entry.getValue()))

spring-cloud-netflix-eureka-server/src/test/java/org/springframework/cloud/netflix/eureka/server/EurekaInstanceMonitorTests.java

@@ -28,14 +28,21 @@ import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.cloud.netflix.eureka.server.metrics.EurekaInstanceMonitor;
 import org.springframework.context.annotation.Configuration;
 
+import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.awaitility.Awaitility.await;
+import static org.awaitility.pollinterval.FibonacciPollInterval.fibonacci;
 import static org.springframework.cloud.netflix.eureka.server.EurekaInstanceFixture.getInstanceInfo;
 import static org.springframework.cloud.netflix.eureka.server.EurekaInstanceFixture.getLeaseInfo;
 
 /**
+ * Tests for {@link EurekaInstanceMonitor}.
+ *
  * @author Wonchul Heo
+ * @author Olga Maciaszek-Sharma
  */
 @SpringBootTest(classes = EurekaInstanceMonitorTests.Application.class,
 		webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT,
@@ -151,9 +158,11 @@ class EurekaInstanceMonitorTests {
 	}
 
 	private void assertEurekaInstance(Map<Tags, Long> meterRegistryCounts) {
-		meterRegistryCounts.forEach((tags,
-				count) -> assertThat((long) meterRegistry.get("eureka.server.instances").tags(tags).gauge().value())
-					.isEqualTo(count));
+		await().atMost(5, SECONDS)
+			.pollInterval(fibonacci())
+			.untilAsserted(() -> meterRegistryCounts.forEach((tags,
+					count) -> assertThat((long) meterRegistry.get("eureka.server.instances").tags(tags).gauge().value())
+						.isEqualTo(count)));
 	}
 
 	@Configuration(proxyBeanMethods = false)

spring-cloud-netflix-eureka-server/src/test/java/org/springframework/cloud/netflix/eureka/server/EurekaInstanceMonitorWithCustomTagsProviderTests.java

@@ -27,16 +27,23 @@ import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.cloud.netflix.eureka.server.metrics.EurekaInstanceMonitor;
 import org.springframework.cloud.netflix.eureka.server.metrics.EurekaInstanceTagsProvider;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
+import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.awaitility.Awaitility.await;
+import static org.awaitility.pollinterval.FibonacciPollInterval.fibonacci;
 import static org.springframework.cloud.netflix.eureka.server.EurekaInstanceFixture.getInstanceInfo;
 import static org.springframework.cloud.netflix.eureka.server.EurekaInstanceFixture.getLeaseInfo;
 
 /**
+ * Tests for {@link EurekaInstanceMonitor} with custom tags provider.
+ *
  * @author Wonchul Heo
+ * @author Olga Maciaszek-Sharma
  */
 @SpringBootTest(classes = EurekaInstanceMonitorWithCustomTagsProviderTests.Application.class,
 		webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT,
@@ -82,9 +89,11 @@ class EurekaInstanceMonitorWithCustomTagsProviderTests {
 	}
 
 	private void assertEurekaInstance(Map<Tags, Long> meterRegistryCounts) {
-		meterRegistryCounts.forEach((tags,
-				count) -> assertThat((long) meterRegistry.get("eureka.server.instances").tags(tags).gauge().value())
-					.isEqualTo(count));
+		await().atMost(5, SECONDS)
+			.pollInterval(fibonacci())
+			.untilAsserted(() -> meterRegistryCounts.forEach((tags,
+					count) -> assertThat((long) meterRegistry.get("eureka.server.instances").tags(tags).gauge().value())
+						.isEqualTo(count)));
 	}
 
 	@Configuration(proxyBeanMethods = false)