[Question] [notice] 9#9: signal 17 (SIGCHLD) received from 12, what does it mean?

[gastonborba]

I have this output in openshift:

2024/06/12 16:31:00 [notice] 9#9: using the "epoll" event method 2024/06/12 16:31:00 [notice] 9#9: nginx/1.27.0 2024/06/12 16:31:00 [notice] 9#9: built by gcc 12.2.0 (Debian 12.2.0-14) 2024/06/12 16:31:00 [notice] 9#9: OS: Linux 4.18.0-305.19.1.el8_4.x86_64 2024/06/12 16:31:00 [notice] 9#9: getrlimit(RLIMIT_NOFILE): 1048576:1048576 2024/06/12 16:31:00 [notice] 9#9: start worker processes 2024/06/12 16:31:00 [notice] 9#9: start worker process 15 2024/06/12 16:31:02 [notice] 9#9: signal 17 (SIGCHLD) received from 12 2024/06/12 16:31:02 [notice] 9#9: unknown process 12 exited with code 0

Everything seems to work fine, but I don't know what that message means. When I run the image on my local machine with docker, that notice does not appear. Should I downplay it?

[yosifkit]

2024/06/12 16:31:02 [notice] 9#9: unknown process 12 exited with code 0

That sounds like another process was running in the container and exited. Did you docker exec something that ran to completion? nginx is PID 1 of the container, so it inherits any child processes in the PID namespace and is responsible for reaping processes to clean up "zombies" (i.e., acting on SIGCHLD).

[gastonborba]

I think you are right. Searching in the /var/log folder I found the dynatrace/oneagent folder, then I realized that the openshift cluster has Dynatrace installed. I suspect that notice is Dynatrace doing its thing. Thank you very much for your help.