>>Backend processes are still running even if the postmaster got killed and all other server processes are exited by checking the
>>Postmaster status.
>>And the backend process is providing the service to the client.
>>Is there any problems are possible? If we continue the system for a long time with the above behavior?
>>Until all these kind of backend processes are exited, postmaster is failing to start.
>>Manual cleanup is required for these backend processes? Or is there anyway we can handle?
>Hi Hari.
>
>How exactly do you kill the postmaster? It is suggested you use pg_ctl for server shutdowns/restarts. Check out the option -m: >-m SHUTDOWN-MODE can be "smart", "fast", or "immediate" >Shutdown modes are: > smart quit after all clients have disconnected > fast quit directly, with proper shutdown > immediate quit without complete shutdown; will lead to recovery on restart
>"Smart" will wait for all your backend processes to terminate (or fail if it takes too long). If i remember correctly "fast" will cause the postmaster to exit even if >backends are still up, the equivalent of sending a kill -15 (SIGTERM). And "immediate" is like sending a kill -9 (SIGKILL) i.e. violent shutdown of everything. > >I'm guessing you went for the equivalent of SIGTERM that's why you still have backends running.
Usually we are using the pg_ctl with shutdown option only.
Actually I thought of asking the postmaster crash scenario, which I have simulated with kill -9 PID.
I know postmaster crash is a very rare scenario, In this I want to know what are all the problems can occur?
