What happens if i receive multiple webhook events simultaneously?

[hahnbeelee]

I'm creating a GitHub bot that creates a check run on every commit. It takes about 2 minutes to complete and when another commit is pushed, I noticed that sometimes the previous check is never completed.

Is this an issue with Probot and how it handles multiple events?

[oscard0m]

Hi @hahnbeelee,

In my understanding, this could be related to GitHub's API or the server in charge of receiving these events.

A good way to see if GitHub Events are triggered at the time you expect is to see your GitHub App's Event activity in https://github.com/organizations/<your_org>/settings/apps/<your_github_app>/advanced:

If the timing when the events are triggered looks correct to you we can check the server side. I would be happy to help here.

[hahnbeelee]

Both events are received and for a while they both run simultaneously (since they are both quite long requests) And then the first one just stops abruptly. I was curious if there is any internal logic within probot that limits multiple threads from running simultaneously?

[oscard0m]

As far as I know, Probot uses @octokit/webhooks in its core and yes, it should be handling requests in parallel (unless there is a bug) according to Octokit's documentation:

Runs all handlers set with webhooks.on() in parallel and waits for them to finish.

---

There is the possibility some exception is thrown during the execution of one of your event handlers. Are you registering an .onError() handler? This could help to discard that possibility:

module.exports = (app) => {
  app.on("issues.opened", async (context) => {
    ...
  });

  app.onAny(async (context) => {
    ...
  });

  app.onError(async (error) => {
    app.log.error(error);
  });
};

[gr2m]

After 9s, @octokit/webhooks returns a 202 response, is that what you are seeing?
https://github.com/octokit/webhooks.js/blob/0942fec50bb6d7c5def541c9f245c7d152014f08/src/middleware/node/middleware.ts#L68-L69

[oscard0m]

After 9s, @octokit/webhooks returns a 202 response, is that what you are seeing? https://github.com/octokit/webhooks.js/blob/0942fec50bb6d7c5def541c9f245c7d152014f08/src/middleware/node/middleware.ts#L68-L69

It's fun because I don't remember this piece of code and I was part of the contribution 🤣