Merge remote-tracking branch 'origin/3.1.x'

Author: OlgaMaciaszek

docs/src/main/asciidoc/_configprops.adoc

@@ -63,6 +63,7 @@
 |spring.cloud.loadbalancer.retry.retryable-exceptions | `+++{}+++` | A `Set` of `Throwable` classes that should trigger a retry.
 |spring.cloud.loadbalancer.retry.retryable-status-codes | `+++{}+++` | A `Set` of status codes that should trigger a retry.
 |spring.cloud.loadbalancer.service-discovery.timeout |  | String representation of Duration of the timeout for calls to service discovery.
+|spring.cloud.loadbalancer.stats.micrometer.enabled | `+++false+++` | Enables Spring Cloud LoadBalancer Micrometer stats.
 |spring.cloud.loadbalancer.sticky-session.add-service-instance-cookie | `+++false+++` | Indicates whether a cookie with the newly selected instance should be added by LoadBalancer.
 |spring.cloud.loadbalancer.sticky-session.instance-id-cookie-name | `+++sc-lb-instance-id+++` | The name of the cookie holding the preferred instance id.
 |spring.cloud.loadbalancer.x-forwarded.enabled | `+++false+++` | To Enable X-Forwarded Headers.

spring-cloud-loadbalancer/src/main/java/org/springframework/cloud/loadbalancer/blocking/client/BlockingLoadBalancerClient.java

@@ -94,6 +94,9 @@ private <T> TimedRequestContext buildRequestContext(LoadBalancerRequest<T> deleg
 	@Override
 	public <T> T execute(String serviceId, ServiceInstance serviceInstance, LoadBalancerRequest<T> request)
 			throws IOException {
+		if (serviceInstance == null) {
+			throw new IllegalArgumentException("Service Instance cannot be null");
+		}
 		DefaultResponse defaultResponse = new DefaultResponse(serviceInstance);
 		Set<LoadBalancerLifecycle> supportedLifecycleProcessors = getSupportedLifecycleProcessors(serviceId);
 		Request lbRequest = request instanceof Request ? (Request) request : new DefaultRequest<>();

spring-cloud-loadbalancer/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -38,6 +38,12 @@
 			"name": "spring.cloud.loadbalancer.eager-load.clients",
 			"description": "Names of the clients.",
 			"type": "java.util.List"
+		},
+		{
+			"defaultValue": "false",
+			"name": "spring.cloud.loadbalancer.stats.micrometer.enabled",
+			"description": "Enables Spring Cloud LoadBalancer Micrometer stats.",
+			"type": "java.lang.Boolean"
 		}
 	]
 }