Re: postgresql.conf recommendations

Josh:

Are you able to share your systemtap script? Our problem will be to try and
regenerate the same amount of traffic/load that we see in production. We
could replay our queries, but we don't even capture a full set because it'd
be roughly 150GB per day.

johnny

On Thu, Feb 7, 2013 at 12:49 PM, Josh Krupka <jkrupka(at)gmail(dot)com> wrote:

> Just as an update from my angle on the THP side... I put together a
> systemtap script last night and so far it's confirming my theory (at least
> in our environment). I want to go through some more data and make some
> changes on our test box to see if we can make it go away before declaring
> success - it's always possible two problems are intertwined or that the THP
> thing is only showing up because of the *real* problem... you know how it
> goes.
>
> Basically the systemtap script does this:
> - probes the compaction function
> - keeps track of the number of calls to it and aggregate time spent in it
> by process
> - at the end spit out the collected info.
>
> So far when I run the script for a short period of time that I know THP
> compactions are happening, I have been able to match up the compaction
> duration collected via systemtap with a query in the pg logs that took that
> amount of time or slightly longer (as expected). A lot of these are only a
> second or so, so I haven't been able to catch everything, but at least the
> data I am getting is consistent.
>
> Will be interested to see what you find Johnny.
>