Fix gh 629 new (#683)

* Swaps deprecated ConditionalOnEnabledEndpoint for updated annotation.

Swaps with ConditionalOnAvailableEndpoint

* Migrates to new OutputCaptureRule

* Migrates to new OutputCaptureRule

* Add health check loadBalancing implementation.

* Make isAlive() method protected.

Co-authored-by: Spencer Gibb <spencer@gibb.tech>

docs/src/main/asciidoc/_configprops.adoc

@@ -28,10 +28,13 @@
 |spring.cloud.inetutils.timeout-seconds | 1 | Timeout, in seconds, for calculating hostname.
 |spring.cloud.inetutils.use-only-site-local-interfaces | false | Whether to use only interfaces with site local addresses. See {@link InetAddress#isSiteLocalAddress()} for more details.
 |spring.cloud.loadbalancer.cache.caffeine.spec |  | The spec to use to create caches. See CaffeineSpec for more details on the spec format.
+|spring.cloud.loadbalancer.cache.capacity | 256 | Initial cache capacity expressed as int.
 |spring.cloud.loadbalancer.cache.ttl | 30s | Time To Live - time counted from writing of the record, after which cache entries are expired, expressed as a {@link Duration}. The property {@link String} has to be in keeping with the appropriate syntax as specified in Spring Boot <code>StringToDurationConverter</code>. @see <a href= "https://github.com/spring-projects/spring-boot/blob/master/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/convert/StringToDurationConverter.java">StringToDurationConverter.java</a>
+|spring.cloud.loadbalancer.health-check.initial-delay | 0 | Initial delay value for the HealthCheck scheduler.
+|spring.cloud.loadbalancer.health-check.interval | 30s | Interval for rerunning the HealthCheck scheduler.
+|spring.cloud.loadbalancer.health-check.path |  | 
 |spring.cloud.loadbalancer.retry.enabled | true | 
 |spring.cloud.loadbalancer.ribbon.enabled | true | Causes `RibbonLoadBalancerClient` to be used by default.
-|spring.cloud.loadbalancer.zone |  | A {@link String} representation of the <code>zone</code> used for filtering instances by zoned load-balancing implementations.
 |spring.cloud.refresh.enabled | true | Enables autoconfiguration for the refresh scope and associated features.
 |spring.cloud.refresh.extra-refreshable | true | Additional class names for beans to post process into refresh scope.
 |spring.cloud.service-registry.auto-registration.enabled | true | Whether service auto-registration is enabled. Defaults to true.

docs/src/main/asciidoc/spring-cloud-commons.adoc

@@ -906,12 +906,71 @@ public class CustomLoadBalancerConfiguration {
 	@Bean
 	public ServiceInstanceListSupplier discoveryClientServiceInstanceListSupplier(
 			ReactiveDiscoveryClient discoveryClient, Environment environment,
-			LoadBalancerProperties loadBalancerProperties,
+			LoadBalancerZoneConfig zoneConfig,
 			ApplicationContext context) {
 		DiscoveryClientServiceInstanceListSupplier firstDelegate = new DiscoveryClientServiceInstanceListSupplier(
 				discoveryClient, environment);
 		ZonePreferenceServiceInstanceListSupplier delegate = new ZonePreferenceServiceInstanceListSupplier(firstDelegate,
-				loadBalancerProperties);
+				zoneConfig);
+		ObjectProvider<LoadBalancerCacheManager> cacheManagerProvider = context
+				.getBeanProvider(LoadBalancerCacheManager.class);
+		if (cacheManagerProvider.getIfAvailable() != null) {
+			return new CachingServiceInstanceListSupplier(delegate,
+					cacheManagerProvider.getIfAvailable());
+		}
+		return delegate;
+	}
+	}
+----
+
+=== Instance Health-Check for LoadBalancer
+
+It is possible to enable a scheduled HealthCheck for the LoadBalancer. The `HealthCheckServiceInstanceListSupplier`
+is provided for that. It regularly verifies if the instances provided by a delegate
+`ServiceInstanceListSupplier` are still alive and only returns the healthy instances,
+unless there are none - then it returns all the retrieved instances.
+
+TIP: This mechanism is particularly helpful while using the `SimpleDiscoveryClient`. For the
+clients backed by an actual Service Registry, it's not necessary to use, as we already get
+healthy instances after querying the external ServiceDiscovery.
+
+The `HealthCheckServiceInstanceListSupplier` uses `InstanceHealthChecker` to verify if the instances are
+alive. We provide a default `PingHealthChecker` instance. It uses `WebClient` to execute
+requests against the `health` endpoint of the instance. You can also provide your own implementation
+of `InstanceHealthChecker` instead.
+
+`HealthCheckServiceInstanceListSupplier` uses properties prefixed with
+`spring.cloud.loadbalancer.healthcheck`. You can set the `initialDelay` and `interval`
+for the scheduler.
+
+For the `PingHealthChecker`, you can set the default path for the healthcheck URL by setting
+the value of the `spring.cloud.loadbalancer.healthcheck.path.default`. You can also set a specific value
+for any given service by setting the value of the `spring.cloud.loadbalancer.healthcheck.path.[SERVICE_ID]`,
+substituting the `[SERVICE_ID]` with the correct ID of your service. If the path is not set,
+`/actuator/health` is used by default.
+
+In order to use the health-check scheduler approach, you will have to instantiate a `HealthCheckServiceInstanceListSupplier` bean in a <<custom-loadbalancer-configuration,custom configuration>>.
+
+We use delegates to work with `ServiceInstanceListSupplier` beans.
+We suggest passing a `DiscoveryClientServiceInstanceListSupplier` delegate in the constructor of `HealthCheckServiceInstanceListSupplier` and, in turn, wrapping the latter with a `CachingServiceInstanceListSupplier` to leverage <<loadbalancer-caching, LoadBalancer caching mechanism>>.
+
+You could use this sample configuration to set it up:
+
+[[zoned-based-custom-loadbalancer-configuration]]
+[source,java,indent=0]
+----
+public class CustomLoadBalancerConfiguration {
+
+	@Bean
+	public ServiceInstanceListSupplier discoveryClientServiceInstanceListSupplier(
+			ReactiveDiscoveryClient discoveryClient, Environment environment,
+			LoadBalancerProperties loadBalancerProperties,
+			ApplicationContext context,
+			InstanceHealthChecker healthChecker) {
+		DiscoveryClientServiceInstanceListSupplier firstDelegate = new DiscoveryClientServiceInstanceListSupplier(
+				discoveryClient, environment);
+		HealthCheckServiceInstanceListSupplier delegate = new HealthCheckServiceInstanceListSupplier(firstDelegate,
+				loadBalancerProperties, healthChecker);
 		ObjectProvider<LoadBalancerCacheManager> cacheManagerProvider = context
 				.getBeanProvider(LoadBalancerCacheManager.class);
 		if (cacheManagerProvider.getIfAvailable() != null) {

spring-cloud-commons/src/main/java/org/springframework/cloud/client/loadbalancer/reactive/LoadBalancerProperties.java

@@ -16,7 +16,11 @@
 
 package org.springframework.cloud.client.loadbalancer.reactive;
 
+import java.time.Duration;
+import java.util.Map;
+
 import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.util.LinkedCaseInsensitiveMap;
 
 /**
  * A {@link ConfigurationProperties} bean for Spring Cloud LoadBalancer.
@@ -28,17 +32,56 @@ import org.springframework.boot.context.properties.ConfigurationProperties;
 public class LoadBalancerProperties {
 
 	/**
-	 * A {@link String} representation of the <code>zone</code> used for filtering
-	 * instances by zoned load-balancing implementations.
+	 * Properties for <code>HealthCheckServiceInstanceListSupplier</code>.
 	 */
-	private String zone;
+	private HealthCheck healthCheck = new HealthCheck();
 
-	public String getZone() {
-		return zone;
+	public HealthCheck getHealthCheck() {
+		return healthCheck;
 	}
 
-	public void setZone(String zone) {
-		this.zone = zone;
+	public void setHealthCheck(HealthCheck healthCheck) {
+		this.healthCheck = healthCheck;
+	}
+
+	public static class HealthCheck {
+
+		/**
+		 * Initial delay value for the HealthCheck scheduler.
+		 */
+		private int initialDelay = 0;
+
+		/**
+		 * Interval for rerunning the HealthCheck scheduler.
+		 */
+		private Duration interval = Duration.ofSeconds(30);
+
+		private Map<String, String> path = new LinkedCaseInsensitiveMap<>();
+
+		public int getInitialDelay() {
+			return initialDelay;
+		}
+
+		public void setInitialDelay(int initialDelay) {
+			this.initialDelay = initialDelay;
+		}
+
+		public Map<String, String> getPath() {
+			return path;
+		}
+
+		public void setPath(Map<String, String> path) {
+			this.path = path;
+		}
+
+		public Duration getInterval() {
+			return interval;
+		}
+
+		public void setInterval(Duration interval) {
+			this.interval = interval;
+		}
+
 	}
 
 }

spring-cloud-loadbalancer/src/main/java/org/springframework/cloud/loadbalancer/annotation/LoadBalancerClientConfiguration.java

@@ -19,14 +19,12 @@ package org.springframework.cloud.loadbalancer.annotation;
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
-import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.cloud.client.ConditionalOnBlockingDiscoveryEnabled;
 import org.springframework.cloud.client.ConditionalOnDiscoveryEnabled;
 import org.springframework.cloud.client.ConditionalOnReactiveDiscoveryEnabled;
 import org.springframework.cloud.client.ServiceInstance;
 import org.springframework.cloud.client.discovery.DiscoveryClient;
 import org.springframework.cloud.client.discovery.ReactiveDiscoveryClient;
-import org.springframework.cloud.client.loadbalancer.reactive.LoadBalancerProperties;
 import org.springframework.cloud.loadbalancer.cache.LoadBalancerCacheManager;
 import org.springframework.cloud.loadbalancer.core.CachingServiceInstanceListSupplier;
 import org.springframework.cloud.loadbalancer.core.CachingServiceInstanceSupplier;
@@ -49,18 +47,11 @@ import org.springframework.core.env.Environment;
  * @author Tim Ysewyn
  */
 @Configuration(proxyBeanMethods = false)
-@EnableConfigurationProperties(LoadBalancerProperties.class)
 @ConditionalOnDiscoveryEnabled
 public class LoadBalancerClientConfiguration {
 
 	private static final int REACTIVE_SERVICE_INSTANCE_SUPPLIER_ORDER = 193827465;
 
-	@Bean
-	@ConditionalOnMissingBean
-	LoadBalancerProperties loadBalancerProperties() {
-		return new LoadBalancerProperties();
-	}
-
 	@Bean
 	@ConditionalOnMissingBean
 	public ReactorLoadBalancer<ServiceInstance> reactorServiceInstanceLoadBalancer(

spring-cloud-loadbalancer/src/main/java/org/springframework/cloud/loadbalancer/config/LoadBalancerAutoConfiguration.java

@@ -22,7 +22,9 @@ import java.util.List;
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.autoconfigure.AutoConfigureBefore;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.cloud.client.loadbalancer.reactive.LoadBalancerBeanPostProcessorAutoConfiguration;
+import org.springframework.cloud.client.loadbalancer.reactive.LoadBalancerProperties;
 import org.springframework.cloud.client.loadbalancer.reactive.ReactiveLoadBalancerAutoConfiguration;
 import org.springframework.cloud.client.loadbalancer.reactive.ReactorLoadBalancerClientAutoConfiguration;
 import org.springframework.cloud.loadbalancer.annotation.LoadBalancerClientSpecification;
@@ -30,6 +32,7 @@ import org.springframework.cloud.loadbalancer.annotation.LoadBalancerClients;
 import org.springframework.cloud.loadbalancer.support.LoadBalancerClientFactory;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.Environment;
 
 /**
  * @author Spencer Gibb
@@ -37,6 +40,7 @@ import org.springframework.context.annotation.Configuration;
  */
 @Configuration(proxyBeanMethods = false)
 @LoadBalancerClients
+@EnableConfigurationProperties(LoadBalancerProperties.class)
 @AutoConfigureBefore({ ReactorLoadBalancerClientAutoConfiguration.class,
 		LoadBalancerBeanPostProcessorAutoConfiguration.class,
 		ReactiveLoadBalancerAutoConfiguration.class })
@@ -49,6 +53,13 @@ public class LoadBalancerAutoConfiguration {
 		this.configurations = configurations;
 	}
 
+	@Bean
+	@ConditionalOnMissingBean
+	public LoadBalancerZoneConfig zoneConfig(Environment environment) {
+		return new LoadBalancerZoneConfig(
+				environment.getProperty("spring.cloud.loadbalancer.zone"));
+	}
+
 	@ConditionalOnMissingBean
 	@Bean
 	public LoadBalancerClientFactory loadBalancerClientFactory() {

spring-cloud-loadbalancer/src/main/java/org/springframework/cloud/loadbalancer/config/LoadBalancerZoneConfig.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2012-2019 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.cloud.loadbalancer.config;
+
+/**
+ * @author Olga Maciaszek-Sharma
+ */
+public class LoadBalancerZoneConfig {
+
+	/**
+	 * A {@link String} representation of the <code>zone</code> used for filtering
+	 * instances by zoned load-balancing implementations.
+	 */
+	private String zone;
+
+	public LoadBalancerZoneConfig(String zone) {
+		this.zone = zone;
+	}
+
+	public String getZone() {
+		return zone;
+	}
+
+	public void setZone(String zone) {
+		this.zone = zone;
+	}
+
+}

spring-cloud-loadbalancer/src/main/java/org/springframework/cloud/loadbalancer/core/HealthCheckServiceInstanceListSupplier.java

@@ -0,0 +1,136 @@
+/*
+ * Copyright 2012-2019 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.cloud.loadbalancer.core;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.FluxSink;
+import reactor.core.publisher.Mono;
+import reactor.core.scheduler.Schedulers;
+
+import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.client.loadbalancer.reactive.LoadBalancerProperties;
+import org.springframework.http.HttpStatus;
+import org.springframework.web.reactive.function.client.WebClient;
+import org.springframework.web.util.UriComponentsBuilder;
+
+/**
+ * A {@link ServiceInstanceListSupplier} implementation that verifies whether the
+ * instances are alive and only returns the healthy one, unless there are none. Uses
+ * {@link WebClient} to ping the <code>health</code> endpoint of the instances.
+ *
+ * @author Olga Maciaszek-Sharma
+ * @since 2.2.0
+ */
+public class HealthCheckServiceInstanceListSupplier
+		implements ServiceInstanceListSupplier {
+
+	private static final Log LOG = LogFactory
+			.getLog(HealthCheckServiceInstanceListSupplier.class);
+
+	private final ServiceInstanceListSupplier delegate;
+
+	private final LoadBalancerProperties.HealthCheck healthCheck;
+
+	private final WebClient webClient;
+
+	private final String defaultHealthCheckPath;
+
+	private List<ServiceInstance> instances = Collections
+			.synchronizedList(new ArrayList<>());
+
+	private List<ServiceInstance> healthyInstances = Collections
+			.synchronizedList(new ArrayList<>());
+
+	public HealthCheckServiceInstanceListSupplier(ServiceInstanceListSupplier delegate,
+			LoadBalancerProperties.HealthCheck healthCheck, WebClient webClient) {
+		this.delegate = delegate;
+		this.healthCheck = healthCheck;
+		defaultHealthCheckPath = healthCheck.getPath().getOrDefault("default",
+				"/actuator/health");
+		this.webClient = webClient;
+		initInstances();
+
+	}
+
+	private void initInstances() {
+		delegate.get().subscribe(delegateInstances -> {
+			instances.clear();
+			instances.addAll(delegateInstances);
+		});
+
+		Flux<List<ServiceInstance>> healthCheckFlux = healthCheckFlux();
+
+		healthCheckFlux.subscribe(verifiedInstances -> {
+			healthyInstances.clear();
+			healthyInstances.addAll(verifiedInstances);
+		});
+	}
+
+	protected Flux<List<ServiceInstance>> healthCheckFlux() {
+		return Flux.create(emitter -> Schedulers
+				.newSingle("Health Check Verifier: " + getServiceId(), true)
+				.schedulePeriodically(() -> {
+					List<ServiceInstance> verifiedInstances = new ArrayList<>();
+					Flux.fromIterable(instances).filterWhen(this::isAlive)
+							.subscribe(serviceInstance -> {
+								verifiedInstances.add(serviceInstance);
+								emitter.next(verifiedInstances);
+							});
+				}, healthCheck.getInitialDelay(), healthCheck.getInterval().toMillis(),
+						TimeUnit.MILLISECONDS),
+				FluxSink.OverflowStrategy.LATEST);
+	}
+
+	@Override
+	public String getServiceId() {
+		return delegate.getServiceId();
+	}
+
+	@Override
+	public Flux<List<ServiceInstance>> get() {
+		if (!healthyInstances.isEmpty()) {
+			return Flux.defer(() -> Flux.fromIterable(healthyInstances).collectList());
+		}
+		// If there are no healthy instances, it might be better to still retry on all of
+		// them
+		if (LOG.isWarnEnabled()) {
+			LOG.warn(
+					"No verified healthy instances were found, returning all listed instances.");
+		}
+		return Flux.defer(() -> Flux.fromIterable(instances).collectList());
+	}
+
+	protected Mono<Boolean> isAlive(ServiceInstance serviceInstance) {
+		String healthCheckPropertyValue = healthCheck.getPath()
+				.get(serviceInstance.getServiceId());
+		String healthCheckPath = healthCheckPropertyValue != null
+				? healthCheckPropertyValue : defaultHealthCheckPath;
+		return webClient.get()
+				.uri(UriComponentsBuilder.fromUri(serviceInstance.getUri())
+						.path(healthCheckPath).build().toUri())
+				.exchange()
+				.map(clientResponse -> HttpStatus.OK.equals(clientResponse.statusCode()));
+	}
+
+}

spring-cloud-loadbalancer/src/main/java/org/springframework/cloud/loadbalancer/core/ZonePreferenceServiceInstanceListSupplier.java

@@ -23,7 +23,7 @@ import java.util.Map;
 import reactor.core.publisher.Flux;
 
 import org.springframework.cloud.client.ServiceInstance;
-import org.springframework.cloud.client.loadbalancer.reactive.LoadBalancerProperties;
+import org.springframework.cloud.loadbalancer.config.LoadBalancerZoneConfig;
 
 /**
  * An implementation of {@link ServiceInstanceListSupplier} that filters instances
@@ -42,14 +42,14 @@ public class ZonePreferenceServiceInstanceListSupplier
 
 	private final ServiceInstanceListSupplier delegate;
 
-	private final LoadBalancerProperties loadBalancerProperties;
+	private final LoadBalancerZoneConfig zoneConfig;
 
 	private String zone;
 
 	public ZonePreferenceServiceInstanceListSupplier(ServiceInstanceListSupplier delegate,
-			LoadBalancerProperties loadBalancerProperties) {
+			LoadBalancerZoneConfig zoneConfig) {
 		this.delegate = delegate;
-		this.loadBalancerProperties = loadBalancerProperties;
+		this.zoneConfig = zoneConfig;
 	}
 
 	@Override
@@ -64,7 +64,7 @@ public class ZonePreferenceServiceInstanceListSupplier
 
 	private List<ServiceInstance> filteredByZone(List<ServiceInstance> serviceInstances) {
 		if (zone == null) {
-			zone = loadBalancerProperties.getZone();
+			zone = zoneConfig.getZone();
 		}
 		if (zone != null) {
 			List<ServiceInstance> filteredInstances = new ArrayList<>();

spring-cloud-loadbalancer/src/test/java/org/springframework/cloud/loadbalancer/core/HealthCheckServiceInstanceListSupplierTests.java

@@ -0,0 +1,126 @@
+/*
+ * Copyright 2012-2019 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.cloud.loadbalancer.core;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.cloud.client.DefaultServiceInstance;
+import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.client.loadbalancer.reactive.LoadBalancerProperties;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.mock.env.MockEnvironment;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.reactive.function.client.WebClient;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link HealthCheckServiceInstanceListSupplier}.
+ *
+ * @author Olga Maciaszek-Sharma
+ */
+@ExtendWith(SpringExtension.class)
+@SpringBootTest(
+		classes = HealthCheckServiceInstanceListSupplierTests.TestApplication.class,
+		webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+class HealthCheckServiceInstanceListSupplierTests {
+
+	@LocalServerPort
+	private int port;
+
+	private final WebClient webClient = WebClient.create();
+
+	private LoadBalancerProperties.HealthCheck healthCheck = new LoadBalancerProperties.HealthCheck();
+
+	@SuppressWarnings("ConstantConditions")
+	@Test
+	void shouldCheckInstanceWithProvidedHealthCheckPath() {
+		healthCheck.getPath().put("ignored-service", "/health");
+		HealthCheckServiceInstanceListSupplier listSupplier = new HealthCheckServiceInstanceListSupplier(
+				ServiceInstanceListSupplier.FixedServiceInstanceListSupplier
+						.with(new MockEnvironment()).build(),
+				healthCheck, webClient);
+		ServiceInstance serviceInstance = new DefaultServiceInstance("ignored-service-1",
+				"ignored-service", "127.0.0.1", port, false);
+
+		boolean alive = listSupplier.isAlive(serviceInstance).block();
+
+		assertThat(alive).isTrue();
+	}
+
+	@SuppressWarnings("ConstantConditions")
+	@Test
+	void shouldCheckInstanceWithDefaultHealthCheckPath() {
+		HealthCheckServiceInstanceListSupplier listSupplier = new HealthCheckServiceInstanceListSupplier(
+				ServiceInstanceListSupplier.FixedServiceInstanceListSupplier
+						.with(new MockEnvironment()).build(),
+				healthCheck, webClient);
+		ServiceInstance serviceInstance = new DefaultServiceInstance("ignored-service-1",
+				"ignored-service", "127.0.0.1", port, false);
+
+		boolean alive = listSupplier.isAlive(serviceInstance).block();
+
+		assertThat(alive).isTrue();
+	}
+
+	@SuppressWarnings("ConstantConditions")
+	@Test
+	void shouldReturnFalseIfEndpointNotFound() {
+		healthCheck.getPath().put("ignored-service", "/test");
+		HealthCheckServiceInstanceListSupplier listSupplier = new HealthCheckServiceInstanceListSupplier(
+				ServiceInstanceListSupplier.FixedServiceInstanceListSupplier
+						.with(new MockEnvironment()).build(),
+				healthCheck, webClient);
+		ServiceInstance serviceInstance = new DefaultServiceInstance("ignored-service-1",
+				"ignored-service", "127.0.0.1", port, false);
+
+		boolean alive = listSupplier.isAlive(serviceInstance).block();
+
+		assertThat(alive).isFalse();
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@EnableAutoConfiguration
+	@RestController
+	static class TestApplication {
+
+		public static void main(String[] args) {
+			SpringApplication.run(
+					HealthCheckServiceInstanceListSupplierTests.TestApplication.class,
+					args);
+		}
+
+		@GetMapping("/health")
+		void healthCheck() {
+
+		}
+
+		@GetMapping("/actuator/health")
+		void defaultHealthCheck() {
+
+		}
+
+	}
+
+}

spring-cloud-loadbalancer/src/test/java/org/springframework/cloud/loadbalancer/core/ZonePreferenceServiceInstanceListSupplierTests.java

@@ -27,7 +27,7 @@ import reactor.core.publisher.Flux;
 
 import org.springframework.cloud.client.DefaultServiceInstance;
 import org.springframework.cloud.client.ServiceInstance;
-import org.springframework.cloud.client.loadbalancer.reactive.LoadBalancerProperties;
+import org.springframework.cloud.loadbalancer.config.LoadBalancerZoneConfig;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatCode;
@@ -44,10 +44,10 @@ class ZonePreferenceServiceInstanceListSupplierTests {
 	private DiscoveryClientServiceInstanceListSupplier delegate = mock(
 			DiscoveryClientServiceInstanceListSupplier.class);
 
-	private LoadBalancerProperties loadBalancerProperties = new LoadBalancerProperties();
+	private LoadBalancerZoneConfig zoneConfig = new LoadBalancerZoneConfig(null);
 
 	private ZonePreferenceServiceInstanceListSupplier supplier = new ZonePreferenceServiceInstanceListSupplier(
-			delegate, loadBalancerProperties);
+			delegate, zoneConfig);
 
 	private ServiceInstance first = serviceInstance("test-1", buildZoneMetadata("zone1"));
 
@@ -63,7 +63,7 @@ class ZonePreferenceServiceInstanceListSupplierTests {
 
 	@Test
 	void shouldFilterInstancesByZone() {
-		loadBalancerProperties.setZone("zone1");
+		zoneConfig.setZone("zone1");
 		when(delegate.get()).thenReturn(
 				Flux.just(Arrays.asList(first, second, third, fourth, fifth)));
 
@@ -78,7 +78,7 @@ class ZonePreferenceServiceInstanceListSupplierTests {
 
 	@Test
 	void shouldReturnAllInstancesIfNoZoneInstances() {
-		loadBalancerProperties.setZone("zone1");
+		zoneConfig.setZone("zone1");
 		when(delegate.get()).thenReturn(Flux.just(Arrays.asList(third, fourth)));
 
 		List<ServiceInstance> filtered = supplier.get().blockFirst();
@@ -89,7 +89,7 @@ class ZonePreferenceServiceInstanceListSupplierTests {
 
 	@Test
 	void shouldNotThrowNPEIfNullInstanceMetadata() {
-		loadBalancerProperties.setZone("zone1");
+		zoneConfig.setZone("zone1");
 		when(delegate.get()).thenReturn(
 				Flux.just(Collections.singletonList(serviceInstance("test-6", null))));
 		assertThatCode(() -> supplier.get().blockFirst()).doesNotThrowAnyException();
@@ -97,7 +97,7 @@ class ZonePreferenceServiceInstanceListSupplierTests {
 
 	@Test
 	void shouldReturnAllInstancesIfNoZone() {
-		loadBalancerProperties.setZone(null);
+		zoneConfig.setZone(null);
 		when(delegate.get())
 				.thenReturn(Flux.just(Arrays.asList(first, second, third, fourth)));