Added GRPC Health service to Ad Service

Also added
1. timeout to getAd RPC call in frontend.
2. Async thread for stackdriver init.

kubernetes-manifests/adservice.yaml

@@ -41,12 +41,12 @@ spec:
         readinessProbe:
           tcpSocket:
             port: 9555
-          initialDelaySeconds: 15
+          initialDelaySeconds: 5
           periodSeconds: 10
         livenessProbe:
           tcpSocket:
             port: 9555
-          initialDelaySeconds: 15
+          initialDelaySeconds: 10
           periodSeconds: 10
 ---
 apiVersion: v1

src/adservice/build.gradle

@@ -25,7 +25,7 @@ repositories {
 group = "adservice"
 version = "0.1.0-SNAPSHOT" // CURRENT_OPENCENSUS_VERSION
 
-def opencensusVersion = "0.14.0" // LATEST_OPENCENSUS_RELEASE_VERSION
+def opencensusVersion = "0.15.0" // LATEST_OPENCENSUS_RELEASE_VERSION
 def grpcVersion = "1.10.1" // CURRENT_GRPC_VERSION
 def prometheusVersion = "0.3.0"
 
@@ -51,6 +51,7 @@ dependencies {
                 "io.grpc:grpc-protobuf:${grpcVersion}",
                 "io.grpc:grpc-stub:${grpcVersion}",
                 "io.grpc:grpc-netty:${grpcVersion}",
+                "io.grpc:grpc-services:${grpcVersion}",
                 "io.prometheus:simpleclient_httpserver:${prometheusVersion}"
 
         runtime "io.opencensus:opencensus-impl:${opencensusVersion}",

src/adservice/src/main/java/hipstershop/AdService.java

@@ -23,7 +23,9 @@ import hipstershop.Demo.AdResponse;
 import io.grpc.Server;
 import io.grpc.ServerBuilder;
 import io.grpc.StatusRuntimeException;
+import io.grpc.health.v1.HealthCheckResponse.ServingStatus;
 import io.grpc.stub.StreamObserver;
+import io.grpc.services.*;
 import io.opencensus.common.Duration;
 import io.opencensus.common.Scope;
 import io.opencensus.contrib.grpc.metrics.RpcViews;
@@ -55,11 +57,15 @@ public class AdService {
 
   private int MAX_ADS_TO_SERVE = 2;
   private Server server;
+  private HealthStatusManager healthMgr;
 
   static final AdService service = new AdService();
   private void start() throws IOException {
     int port = Integer.parseInt(System.getenv("PORT"));
-    server = ServerBuilder.forPort(port).addService(new AdServiceImpl()).build().start();
+    healthMgr = new HealthStatusManager();
+
+    server = ServerBuilder.forPort(port).addService(new AdServiceImpl())
+        .addService(healthMgr.getHealthService()).build().start();
     logger.info("Ad Service started, listening on " + port);
     Runtime.getRuntime()
         .addShutdownHook(
@@ -72,10 +78,12 @@ public class AdService {
                 System.err.println("*** server shut down");
               }
             });
+    healthMgr.setStatus("", ServingStatus.SERVING);
   }
 
   private void stop() {
     if (server != null) {
+      healthMgr.clearStatus("");
       server.shutdown();
     }
   }
@@ -173,11 +181,8 @@ public class AdService {
     logger.info("Default Ads initialized");
   }
 
-  /** Main launches the server from the command line. */
-  public static void main(String[] args) throws IOException, InterruptedException {
-    // Add final keyword to pass checkStyle.
-
-    initializeAds();
+  public static void initStackdriver() {
+    logger.info("Initialize StackDriver");
 
     // Registers all RPC views.
     RpcViews.registerAllViews();
@@ -210,6 +215,20 @@ public class AdService {
         }
       }
     }
+    logger.info("StackDriver initialization complete.");
+  }
+
+  /** Main launches the server from the command line. */
+  public static void main(String[] args) throws IOException, InterruptedException {
+    // Add final keyword to pass checkStyle.
+
+    initializeAds();
+
+    new Thread( new Runnable() {
+      public void run(){
+        initStackdriver();
+      }
+    }).start();
 
     // Register Prometheus exporters and export metrics to a Prometheus HTTPServer.
     PrometheusStatsCollector.createAndRegister();

src/frontend/rpc.go

@@ -16,6 +16,7 @@ package main
 
 import (
 	"context"
+	"time"
 
 	pb "github.com/GoogleCloudPlatform/microservices-demo/src/frontend/genproto"
 
@@ -116,6 +117,9 @@ func (fe *frontendServer) getRecommendations(ctx context.Context, userID string,
 }
 
 func (fe *frontendServer) getAd(ctx context.Context) ([]*pb.Ad, error) {
+	ctx, cancel := context.WithTimeout(ctx, time.Millisecond*100)
+	defer cancel()
+
 	resp, err := pb.NewAdServiceClient(fe.adSvcConn).GetAds(ctx, &pb.AdRequest{
 		ContextKeys: nil,
 	})