Re: High CPU usage from a vacuum process but does nothing

To sum it up, after reboot it looks alright, vacuum finishes promptly.

On 04/10/2017 19:28, Boris S. wrote:
> After migrating the server to a bigger machine, I'm noticing an odd
> behaviour. If I begin vacuuming manually, it starts OK:
>
> <snip>
> 0 pages are entirely empty.
> CPU 0.00s/0.00u sec elapsed 0.00 sec.
> INFO:  analyzing "public.table024484"
> INFO:  "table024484": scanned 111123 of 111123 pages, containing
> 4909226 live rows and 0 dead rows; 150000 rows in sample, 4909226
> estimated total rows
>
> But then it gets stuck indefinitely with high CPU usage and command
> never exits. kill -TERM isn't helping, process stays on with ~99% CPU
> usage. Stracing this process gets me just:
>
> strace: Process 102011 attached
> strace: [ Process PID=102011 runs in x32 mode. ]
>
> Which is an odd message, all other processes give normal strace output.
>
> latest pgsql 9.5 (same on old and new machine)
> Ubuntu 16.04
>
> Values in "cat /proc/102011/io" stay the same.
>
> Autovacuum and other processes, queries aren't affected and can be
> straced normally. Disk IO is low (checked with iostat)
>
> Any ideas on what else to try?
>
>