Add keepalive example

examples/keepalive/README.md

@@ -0,0 +1,16 @@
+# Keepalive
+
+This example illustrates how to set up client-side keepalive pings and
+server-side keepalive pings and connection age and idleness settings.
+
+## Start the server
+
+```
+node server.js
+```
+
+## Start the client
+
+```
+GRPC_TRACE=transport,keepalive GRPC_VERBOSITY=DEBUG node client.js
+```

examples/keepalive/client.js

@@ -0,0 +1,61 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+const grpc = require('@grpc/grpc-js');
+const protoLoader = require('@grpc/proto-loader');
+const parseArgs = require('minimist');
+
+const PROTO_PATH = __dirname + '/../protos/echo.proto';
+
+const packageDefinition = protoLoader.loadSync(
+  PROTO_PATH,
+  {keepCase: true,
+   longs: String,
+   enums: String,
+   defaults: true,
+   oneofs: true
+  });
+const echoProto = grpc.loadPackageDefinition(packageDefinition).grpc.examples.echo;
+
+const keepaliveOptions = {
+  // Ping the server every 10 seconds to ensure the connection is still active
+  'grpc.keepalive_time_ms': 10_000,
+  // Wait 1 second for the ping ack before assuming the connection is dead
+  'grpc.keepalive_timeout_ms': 1_000,
+  // send pings even without active streams
+  'grpc.keepalive_permit_without_calls': 1
+}
+
+function main() {
+  let argv = parseArgs(process.argv.slice(2), {
+    string: 'target',
+    default: {target: 'localhost:50052'}
+  });
+  const client = new echoProto.Echo(argv.target, grpc.credentials.createInsecure(), keepaliveOptions);
+  client.unaryEcho({message: 'keepalive demo'}, (error, value) => {
+    if (error) {
+      console.log(`Unexpected error from UnaryEcho: ${error}`);
+      return;
+    }
+    console.log(`RPC response: ${JSON.stringify(value)}`);
+  });
+  // Keep process alive forever; run with GRPC_TRACE=transport,keepalive GRPC_VERBOSITY=DEBUG to observe ping frames and GOAWAYs due to idleness.
+  setInterval(() => {}, 1000);
+}
+
+main();

examples/keepalive/server.js

@@ -0,0 +1,71 @@
+/*
+ *
+ * Copyright 2024 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+const grpc = require('@grpc/grpc-js');
+const protoLoader = require('@grpc/proto-loader');
+const parseArgs = require('minimist');
+
+const PROTO_PATH = __dirname + '/../protos/echo.proto';
+
+const packageDefinition = protoLoader.loadSync(
+  PROTO_PATH,
+  {keepCase: true,
+   longs: String,
+   enums: String,
+   defaults: true,
+   oneofs: true
+  });
+const echoProto = grpc.loadPackageDefinition(packageDefinition).grpc.examples.echo;
+
+const keepaliveOptions = {
+  // If a client is idle for 15 seconds, send a GOAWAY
+  'grpc.max_connection_idle_ms': 15_000,
+  // If any connection is alive for more than 30 seconds, send a GOAWAY
+  'grpc.max_connection_age_ms': 30_000,
+  // Allow 5 seconds for pending RPCs to complete before forcibly closing connections
+  'grpc.max_connection_age_grace_ms': 5_000,
+  // Ping the client every 5 seconds to ensure the connection is still active
+  'grpc.keepalive_time_ms': 5_000,
+  // Wait 1 second for the ping ack before assuming the connection is dead
+  'grpc.keepalive_timeout_ms': 1_000
+}
+
+function unaryEcho(call, callback) {
+  callback(null, call.request);
+}
+
+const serviceImplementation = {
+  unaryEcho
+};
+
+function main() {
+  const argv = parseArgs(process.argv.slice(2), {
+    string: 'port',
+    default: {port: '50052'}
+  });
+  const server = new grpc.Server(keepaliveOptions);
+  server.addService(echoProto.Echo.service, serviceImplementation);
+  server.bindAsync(`0.0.0.0:${argv.port}`, grpc.ServerCredentials.createInsecure(), (err, port) => {
+    if (err != null) {
+      return console.error(err);
+    }
+    console.log(`gRPC listening on ${port}`)
+  });
+}
+
+main();

examples/package.json

@@ -5,8 +5,8 @@
     "@grpc/proto-loader": "^0.6.0",
     "async": "^1.5.2",
     "google-protobuf": "^3.0.0",
-    "@grpc/grpc-js": "^1.8.0",
-    "@grpc/grpc-js-xds": "^1.8.0",
+    "@grpc/grpc-js": "^1.10.2",
+    "@grpc/grpc-js-xds": "^1.10.0",
     "@grpc/reflection": "^1.0.0",
     "lodash": "^4.6.1",
     "minimist": "^1.2.0"