backport - feat: Add metrics to count VIP address lookups in DiscoveryClient

Author: jasonk000

eureka-client/src/main/java/com/netflix/discovery/DiscoveryClient.java

@@ -129,6 +129,16 @@ public class DiscoveryClient implements EurekaClient {
     private final Timer FETCH_REGISTRY_TIMER = SpectatorUtil.timer(PREFIX + "FetchRegistry", DiscoveryClient.class);
     private final Counter REREGISTER_COUNTER = SpectatorUtil.counter(PREFIX + "Reregister", DiscoveryClient.class);
 
+    // Lookup counters
+    private final Counter LOOKUP_GET_APPLICATION = SpectatorUtil.counter(PREFIX + "Lookup", "getApplication", DiscoveryClient.class);
+    private final Counter LOOKUP_GET_APPLICATIONS = SpectatorUtil.counter(PREFIX + "Lookup", "getApplications", DiscoveryClient.class);
+    private final Counter LOOKUP_GET_APPLICATIONS_FOR_A_REGION = SpectatorUtil.counter(PREFIX + "Lookup", "getApplicationsForARegion", DiscoveryClient.class);
+    private final Counter LOOKUP_GET_INSTANCES_BY_ID = SpectatorUtil.counter(PREFIX + "Lookup", "getInstancesById", DiscoveryClient.class);
+    private final Counter LOOKUP_GET_INSTANCES_BY_VIP = SpectatorUtil.counter(PREFIX + "Lookup", "getInstancesByVipAddress", DiscoveryClient.class);
+    private final Counter LOOKUP_GET_INSTANCES_BY_VIP_AND_APP = SpectatorUtil.counter(PREFIX + "Lookup", "getInstancesByVipAddressAndAppName", DiscoveryClient.class);
+    private final Counter LOOKUP_GET_NEXT_SERVER = SpectatorUtil.counter(PREFIX + "Lookup", "getNextServerFromEureka", DiscoveryClient.class);
+    private final Counter LOOKUP_GET_APPLICATIONS_SERVICE_URL = SpectatorUtil.counter(PREFIX + "Lookup", "getApplicationsServiceUrl", DiscoveryClient.class);
+
     // instance variables
     /**
      * A scheduler to be used for the following 3 tasks:
@@ -459,7 +469,7 @@ public Thread newThread(Runnable r) {
     private void scheduleServerEndpointTask(EurekaTransport eurekaTransport,
                                             AbstractDiscoveryClientOptionalArgs args) {
 
-            
+
         Collection<?> additionalFilters = args == null
                 ? Collections.emptyList()
                 : args.additionalFilters;
@@ -560,6 +570,7 @@ public ApplicationInfoManager getApplicationInfoManager() {
      */
     @Override
     public Application getApplication(String appName) {
+        LOOKUP_GET_APPLICATION.increment();
         return getApplications().getRegisteredApplications(appName);
     }
 
@@ -570,11 +581,13 @@ public Application getApplication(String appName) {
      */
     @Override
     public Applications getApplications() {
+        LOOKUP_GET_APPLICATIONS.increment();
         return localRegionApps.get();
     }
 
     @Override
     public Applications getApplicationsForARegion(@Nullable String region) {
+        LOOKUP_GET_APPLICATIONS_FOR_A_REGION.increment();
         if (instanceRegionChecker.isLocalRegion(region)) {
             return localRegionApps.get();
         } else {
@@ -600,6 +613,7 @@ public Set<String> getAllKnownRegions() {
      */
     @Override
     public List<InstanceInfo> getInstancesById(String id) {
+        LOOKUP_GET_INSTANCES_BY_ID.increment();
         List<InstanceInfo> instancesList = new ArrayList<>();
         for (Application app : this.getApplications()
                 .getRegisteredApplications()) {
@@ -684,6 +698,7 @@ public List<InstanceInfo> getInstancesByVipAddress(String vipAddress, boolean se
     @Override
     public List<InstanceInfo> getInstancesByVipAddress(String vipAddress, boolean secure,
                                                        @Nullable String region) {
+        LOOKUP_GET_INSTANCES_BY_VIP.increment();
         if (vipAddress == null) {
             throw new IllegalArgumentException(
                     "Supplied VIP Address cannot be null");
@@ -704,9 +719,7 @@ public List<InstanceInfo> getInstancesByVipAddress(String vipAddress, boolean se
             return applications.getInstancesByVirtualHostName(vipAddress);
         } else {
             return applications.getInstancesBySecureVirtualHostName(vipAddress);
-
         }
-
     }
 
     /**
@@ -725,6 +738,7 @@ public List<InstanceInfo> getInstancesByVipAddress(String vipAddress, boolean se
     @Override
     public List<InstanceInfo> getInstancesByVipAddressAndAppName(
             String vipAddress, String appName, boolean secure) {
+        LOOKUP_GET_INSTANCES_BY_VIP_AND_APP.increment();
 
         List<InstanceInfo> result = new ArrayList<>();
         if (vipAddress == null && appName == null) {
@@ -779,6 +793,7 @@ public List<InstanceInfo> getInstancesByVipAddressAndAppName(
      */
     @Override
     public InstanceInfo getNextServerFromEureka(String virtualHostname, boolean secure) {
+        LOOKUP_GET_NEXT_SERVER.increment();
         List<InstanceInfo> instanceInfoList = this.getInstancesByVipAddress(
                 virtualHostname, secure);
         if (instanceInfoList == null || instanceInfoList.isEmpty()) {
@@ -800,6 +815,7 @@ public InstanceInfo getNextServerFromEureka(String virtualHostname, boolean secu
      */
     @Override
     public Applications getApplications(String serviceUrl) {
+        LOOKUP_GET_APPLICATIONS_SERVICE_URL.increment();
         try {
             EurekaHttpResponse<Applications> response = clientConfig.getRegistryRefreshSingleVipAddress() == null
                     ? eurekaTransport.queryClient.getApplications()

eureka-client/src/test/java/com/netflix/discovery/DiscoveryClientRegistryTest.java

@@ -16,6 +16,10 @@
 import com.netflix.discovery.shared.transport.EurekaHttpResponse;
 import com.netflix.discovery.shared.transport.SimpleEurekaHttpServer;
 import com.netflix.discovery.util.InstanceInfoGenerator;
+import com.netflix.spectator.api.Counter;
+import com.netflix.spectator.api.DefaultRegistry;
+import com.netflix.spectator.api.Registry;
+import com.netflix.spectator.api.Spectator;
 import org.junit.AfterClass;
 import org.junit.Before;
 import org.junit.BeforeClass;
@@ -52,6 +56,7 @@ public class DiscoveryClientRegistryTest {
 
     private static final EurekaHttpClient requestHandler = mock(EurekaHttpClient.class);
     private static SimpleEurekaHttpServer eurekaHttpServer;
+    private static DefaultRegistry testRegistry;
 
     @Rule
     public DiscoveryClientResource discoveryClientResource = DiscoveryClientResource.newBuilder()
@@ -67,13 +72,18 @@ public class DiscoveryClientRegistryTest {
     @BeforeClass
     public static void setUpClass() throws IOException {
         eurekaHttpServer = new SimpleEurekaHttpServer(requestHandler);
+        testRegistry = new DefaultRegistry();
+        Spectator.globalRegistry().add(testRegistry);
     }
 
     @AfterClass
     public static void tearDownClass() throws Exception {
         if (eurekaHttpServer != null) {
             eurekaHttpServer.shutdown();
         }
+        if (testRegistry != null) {
+            Spectator.globalRegistry().remove(testRegistry);
+        }
     }
 
     @Before
@@ -314,6 +324,28 @@ public void testEurekaClientPeriodicCacheRefreshForDeleteAndNoApplication() thro
         assertEquals(client.getApplications().getRegisteredApplications(), new ArrayList<>());
     }
 
+    @Test
+    public void testLookupMetricsIncremented() throws Exception {
+        Applications applications = InstanceInfoGenerator.newBuilder(2, "app1").build().toApplications();
+        InstanceInfo instance = applications.getRegisteredApplications("app1").getInstances().get(0);
+        String vipAddress = instance.getVIPAddress();
+
+        when(requestHandler.getApplications(TEST_REMOTE_REGION)).thenReturn(
+                anEurekaHttpResponse(200, applications).type(MediaType.APPLICATION_JSON_TYPE).build()
+        );
+
+        Registry registry = Spectator.globalRegistry();
+        Counter vipCounter = registry.counter(
+                registry.createId("DiscoveryClient_Lookup")
+                        .withTag("id", "getInstancesByVipAddress")
+                        .withTag("class", "DiscoveryClient"));
+        long initialCount = vipCounter.count();
+
+        discoveryClientResource.getClient().getInstancesByVipAddress(vipAddress, false);
+
+        assertThat(vipCounter.count(), is(equalTo(initialCount + 1)));
+    }
+
     /**
      * There is a bug, because of which remote registry data structures are not initialized during full registry fetch, only during delta.
      */