Abort outstanding HTTP requests when subscription is closed

[ghost]

Hi!

After a certain event I just want my app to shut down. It seems, though, that gcloud (where I only use pubsub) keeps my App alive. Is there a way to kill pubsub so my App can shut down?

[stephenplusplus]

It is probably a subscription object that is still pulling for new messages. You can quickly stop that process by calling subscription.removeAllListeners()

[ghost]

Hey @stephenplusplus, thanks for your answer.
That did not work for me.
Here a little example of what I mean. This will stay alive:

  let pubsub = gcloud.pubsub({
    projectId: projectId,
    keyFilename: keyPath
  });

  let topic = pubsub.topic('someTopic');

  topic.subscribe('update', function (error, sub) {
    if (error) {
      return console.log(error);
    }

    sub.on('error', function (error) {
      console.log(error);
    });

    sub.on('message', function (message) {
      console.log(message);
    });

    setTimeout(function () {
      sub.removeAllListeners();
    }, 500);
  });

[stephenplusplus]

Got to the bottom of this! Unfortunately, there are a few pieces involved...

1. Removing listeners is the right way to do this 👍, but our code doesn't abort the HTTP request that remains open while waiting for new messages. PR sent: pubsub: allow aborting an active HTTP request + auto-abort when subsc… #1105
2. We need a way to abort requests, but we're limited by one of the libraries we use, retry-request. I just fixed that: googleapis/retry-request@ecb30d0
3. We need a way for the underlying library, request to allow us to abort a request that has a timeout set. PR sent for that here: Cancel timeout on aborted requests request/request#2052

[stephenplusplus]

This is actually going to be resolved by #1070, since we're switching to using gRPC. If all goes well, a release that has this completely resolved will be put out on Monday.