Merge pull request #2563 from murgatroid99/grpc-js_handle_keepalive_error

grpc-js: Handle keepalive ping error

packages/grpc-js/src/transport.ts

@@ -426,6 +426,10 @@ class Http2Transport implements Transport {
     try {
       this.session!.ping(
         (err: Error | null, duration: number, payload: Buffer) => {
+          if (err) {
+            this.keepaliveTrace('Ping failed with error ' + err.message);
+            this.handleDisconnect();
+          }
           this.keepaliveTrace('Received ping response');
           this.clearKeepaliveTimeout();
           this.maybeStartKeepalivePingTimer();