Properly hanlde gRPC session timeout

@@ -19,7 +19,7 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.io.Resources;
 import com.google.common.util.concurrent.FutureCallback;
 import io.grpc.Server;
-import io.grpc.ServerBuilder;
+import io.grpc.netty.NettyServerBuilder;
 import io.grpc.stub.StreamObserver;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -49,6 +49,7 @@ import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
 
 @Service
 @Slf4j
@@ -68,6 +69,8 @@ public class EdgeGrpcService extends EdgeRpcServiceGrpc.EdgeRpcServiceImplBase i
     private String privateKeyResource;
     @Value("${edges.state.persistToTelemetry:false}")
     private boolean persistToTelemetry;
+    @Value("${edges.rpc.client_max_keep_alive_time_sec}")
+    private int clientMaxKeepAliveTimeSec;
 
     @Autowired
     private EdgeContextComponent ctx;
@@ -82,7 +85,9 @@ public class EdgeGrpcService extends EdgeRpcServiceGrpc.EdgeRpcServiceImplBase i
     @PostConstruct
     public void init() {
         log.info("Initializing Edge RPC service!");
-        ServerBuilder builder = ServerBuilder.forPort(rpcPort).addService(this);
+        NettyServerBuilder builder = NettyServerBuilder.forPort(rpcPort)
+                .permitKeepAliveTime(clientMaxKeepAliveTimeSec, TimeUnit.SECONDS)
+                .addService(this);
         if (sslEnabled) {
             try {
                 File certFile = new File(Resources.getResource(certFileResource).toURI());

@@ -590,6 +590,7 @@ edges:
   rpc:
     enabled: "${EDGES_RPC_ENABLED:false}"
     port: "${EDGES_RPC_PORT:7070}"
+    client_max_keep_alive_time_sec: "${EDGES_RPC_CLIENT_MAX_KEEP_ALIVE_TIME_SEC:300}"
     ssl:
       # Enable/disable SSL support
       enabled: "${EDGES_RPC_SSL_ENABLED:false}"

@@ -55,6 +55,8 @@ public class EdgeGrpcClient implements EdgeRpcClient {
     private int rpcPort;
     @Value("${cloud.rpc.timeout}")
     private int timeoutSecs;
+    @Value("${cloud.rpc.keep_alive_time_sec}")
+    private int keepAliveTimeSec;
     @Value("${cloud.rpc.ssl.enabled}")
     private boolean sslEnabled;
     @Value("${cloud.rpc.ssl.cert}")
@@ -73,7 +75,9 @@ public class EdgeGrpcClient implements EdgeRpcClient {
                         Consumer<EdgeConfiguration> onEdgeUpdate,
                         Consumer<DownlinkMsg> onDownlink,
                         Consumer<Exception> onError) {
-        NettyChannelBuilder builder = NettyChannelBuilder.forAddress(rpcHost, rpcPort).usePlaintext();
+        NettyChannelBuilder builder = NettyChannelBuilder.forAddress(rpcHost, rpcPort)
+                .keepAliveTime(keepAliveTimeSec, TimeUnit.SECONDS)
+                .usePlaintext();
         if (sslEnabled) {
             try {
                 builder.sslContext(GrpcSslContexts.forClient().trustManager(new File(Resources.getResource(certResource).toURI())).build());