Process lifecycle on snap refresh

snapd
41

Sorry I was wrong about nginx.
It renews master process as well as child processes in upgrading.

  • Step 0: Initial

master process (nginx.pid)
_ worker process

  • Step 1: SIGUSR2 -> master process

old master process (nginx.pid.oldbin)
_ old worker process
_ new master process (nginx.pid)
_ new worker process

  • Step 2: SIGQUIT -> old master process

new master process (nginx.pid)
_ new worker process