We are running load test against an application that hits a Postgres database.
During the test, we suddenly get an increase in error rate. After analysing the platform and application behaviour, we notice that:
- CPU of Postgres RDS is 100%
- Freeable memory drops on this same server
And in the postgres logs, we see:
2018-08-21 08:19:48 UTC::@:[XXXXX]:LOG: server process (PID XXXX) was terminated by signal 9: Killed
After investigating and reading documentation, it appears one possibility is linux oomkiller running having killed the process.
But since we're on RDS, we cannot access system logs /var/log messages to confirm.
So can somebody:
- confirm that oom killer really runs on AWS RDS for Postgres
- give us a way to check this ?
- give us a way to compute max memory used by Postgres based on number of connections ?
I didn't find the answer here: