=?UTF-8?B?TGF0aWYgZ8O8ZMO8aw==?= <latifguduk@gmail.com> writes:
> One of our production database crashed and got FATAL: the database system
> is in recovery mode. You can find OS version and db version info below.
> 2021-10-05 17:01:08.103 +03 20248 LOG: server process (PID 158856)
> was terminated by signal 9: Killed
That is an external kill. If you didn't do it manually, it's most likely
the Linux OOM killer in action. See
https://www.postgresql.org/docs/current/kernel-resources.html#LINUX-MEMORY-OVERCOMMIT
regards, tom lane