How to exit after calling the request?

[luchenqun]

Describe the bug
I used Node.js to call a gRPC service with an official example. However, after executing the script, Node.js did not exit and I had to manually call process.exit(0) to exit. Below is the relevant JavaScript code I wrote:

import { createPromiseClient } from "@bufbuild/connect";
import { ElizaService } from "@buf/bufbuild_eliza.bufbuild_connect-es/buf/connect/demo/eliza/v1/eliza_connect.js";
import { createGrpcTransport } from "@bufbuild/connect-node";
const transport = createGrpcTransport({
  baseUrl: "https://demo.connect.build",
  httpVersion: "2",
});

async function main() {
  const client = createPromiseClient(ElizaService, transport);
  const res = await client.say({ sentence: "I feel happy." });
  console.log(res);
  // process.exit(0);
}
main();

Environment (please complete the following information):

• @bufbuild/connect-node version: 0.11.0
• Node.js version: 16.16.0

The program will automatically exit in about ten minutes.exited with code=0 in 611.145 seconds

[emcfarlane]

Extending the script with:

await main();

const activeHandles = process._getActiveHandles();
const activeRequests = process._getActiveRequests();
console.log("activeHandles", activeHandles.length, activeHandles);
console.log("activeRequest", activeRequests.length, activeRequests);

shows 3 activeHandles, 2 WriteStream and 1 TLSSocket.

Exits after 10m, I think its a connection pool that is keeping the script from closing.

[luchenqun]

Extending the script with:

await main();

const activeHandles = process._getActiveHandles();
const activeRequests = process._getActiveRequests();
console.log("activeHandles", activeHandles.length, activeHandles);
console.log("activeRequest", activeRequests.length, activeRequests);

shows 3 activeHandles, 2 WriteStream and 1 TLSSocket.

Exits after 10m, I think its a connect pool that is keeping the script from closing.

Thank you for your answer. If it's a connection pool, can we safely exit the program by closing the connection pool?

[timostamm]

Hey @luchenqun, with v0.10.0, clients keep the HTTP/2 connection alive. Node.js respects the active socket and does not exit on it's own.

The default timeout for idle connections is 15 minutes. You can provide a smaller value to let your script exit earlier, for example 5 seconds:

const transport = createGrpcTransport({
  baseUrl: "https://demo.connect.build",
  httpVersion: "2",
+ idleConnectionTimeoutMs: 5000,
});

If waiting for the idle timeout is not helpful in your use case, you can close the connection explicitly. You can find an example at the bottom of this PR description: #673

While this works as intended, it might be surprising without the context. I think we might want to unref the connection so that the code in your example would exit right away.

[timostamm]

The enhancement to this behavior was released in v0.12.0. The example in the description should exit on its own now.