`Instance reached connections hard limit` on fresh instance


Yesterday, I noticed I received the warning Instance reached connections hard limit of 25. I don’t know for how many days this is the case.

What’s even strange is that I have this warning after few seconds on a fresh instance (following a deploy). I know my app is not used but by me at the moment, so it is doubtful I already reach such limit.

2022-11-05T07:59:23.017 runner[cf465021] fra [info] Configuring firecracker
2022-11-05T07:59:23.201 runner[cf465021] fra [info] Starting virtual machine
2022-11-05T07:59:23.392 app[cf465021] fra [info] Starting init (commit: 81d5330)...
2022-11-05T07:59:23.416 app[cf465021] fra [info] Preparing to run: `docker-entrypoint.sh npm start` as root
2022-11-05T07:59:26.408 app[cf465021] fra [info] ✅ app ready: http://localhost:8080
2022-11-05T07:59:27.148 app[cf465021] fra [info] GET /healthcheck 200 - - 246.000 ms
2022-11-05T07:59:54.202 runner[8fc6e6f2] fra [info] Shutting down virtual machine
2022-11-05T07:59:54.297 app[8fc6e6f2] fra [info] Sending signal SIGINT to main child process w/ PID 521
2022-11-05T08:00:07.207 app[cf465021] fra [info] GET /healthcheck 200 - - 9.857 ms
2022-11-05T08:00:07.302 proxy[cf465021] fra [warn] Instance reached connections hard limit of 25
2022-11-05T08:00:25.981 app[cf465021] fra [info] GET /manage 302 - - 26.210 ms

Therefore I have two questions:

  1. What is the meaning of this warning message. I know we can adapt the parameter, but I’d like to understand the impact, and how to brainstorm around this.
  2. How is it even possible for a small app with slow traffic to hit this limit?
  3. And after a fresh instance being deployed?

Thank you for your help :slight_smile: