The following bug has been logged on the website:
Bug reference: 14973
Logged by: Dmitry Shalashov
Email address: skaurus@gmail.com
PostgreSQL version: 10.1
Operating system: Debian 9
Description:
We stumbled upon queries running for a day or more. They are simple ones, so
that should not be happening. And most of the time it don't - very small
share of these queries ends up like this.
Moreover, these queries couldn't be stopped.
pg_stat_activity says that they all have wait_event_type = IPC, wait_event =
BtreePage, state = active
strace tells that they all inside epoll_wait syscall
grep over ps says that they all are "postgres: bgworker: parallel worker for
PID ..."
Looks like some bug in parallel seq scan maybe?
We are going to disable parallel seq scan and restart our server in like 4
hours from now. I can get more debug if asked before that.