On Mon, Jan 4, 2010 at 17:40, Andrew Dunstan <and...@dunslane.net> wrote: > > > Magnus Hagander wrote: >> >> On Mon, Jan 4, 2010 at 17:07, Andrew Dunstan <and...@dunslane.net> wrote: >> >>> >>> Magnus Hagander wrote: >>> >>>> >>>> On Mon, Jan 4, 2010 at 16:45, Alvaro Herrera >>>> <alvhe...@commandprompt.com> >>>> wrote: >>>> >>>> >>>>> >>>>> Magnus Hagander wrote: >>>>> >>>>> >>>>>> >>>>>> I realize this is a very platform-specific thing, but should we >>>>>> consider setting the value of /proc/<pid>/oom_adj when running on >>>>>> linux? See: >>>>>> >>>>>> >>>>> >>>>> >>>>> http://archives.postgresql.org/message-id/20080201223336.GC24780%40alvh.no-ip.org >>>>> >>>>> >>>> >>>> Grr. I had zero recollectoin of that :S >>>> >>>> Can't find a useful consensus though? >>>> >>>> >>>> >>> >>> It is probably worth trying to protect the postmaster in the init script. >>> Beyond that things probably start to get fairly difficult. >>> >> >> Right. But AFAICS (though I haven't tested with -17), it will become >> inherited to children, which is something we'd want to *undo*, no? >> > > > [experiments] > > Yes, darnit, you're right. But it looks like the oom_adj file can be set to > the default by the process owner: > > [and...@sophia ~]$ ls -l /proc/6520/oom_adj > -rw-r--r-- 1 andrew andrew 0 2010-01-04 12:37 /proc/6520/oom_adj > [and...@sophia ~]$ cat /proc/6520/oom_adj > 0 > [and...@sophia ~]$ id > uid=500(andrew) gid=500(andrew) groups=10(wheel),500(andrew) > [and...@sophia ~]$ echo -17 > /proc/6520/oom_adj > -bash: echo: write error: Permission denied > [and...@sophia ~]$ echo 0 > /proc/6520/oom_adj > [and...@sophia ~]$ echo -17 > /proc/6520/oom_adj > -bash: echo: write error: Permission denied > [and...@sophia ~]$ > > But that would be a pain to have to do. > > OTOH, disabling the OOM killer is not always an option. I recently tried it > on one system and had to revert it rapidly because the system stopped > working in minutes. Some software just doesn't live well in such > environments, sadly.
Right. Which is why I like the idea of disabling the OOM killer for the *postmaster*, but not the regular backends. Gives it a chance to recover. It's not nice, but it's better than nothing. -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
