Re: An unkillable connection caused replication delay on my replica

Shawn wrote:

> strace of long-running query pid 6819 loops like this:
> 
>      sendto(10, "<query stuff removed>" NULL, 0) = ? ERESTARTSYS (To be
> restarted if SA_RESTART is set)
>      --- SIGUSR1 {si_signo=SIGUSR1, si_code=SI_USER, si_pid=8719,
> si_uid=3001} ---
>      rt_sigreturn()       
> 
> Where pid 6819 is a long (running for 2 days) running query.  In
> pg_stat_activity, it was still listed as "active".  The query had a horrible
> execution plan and it was being executed via a python script.  I couldn't
> pg_terminate_backend the connection.  I didn't try to "kill -9" it due to
> all the warnings about that and I felt I had something special here.  I
> attached the debugger.

Did you happen to grab a stack trace of PID 6819?


-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services