[rt-users] long page load times with many comments, was: is SELECT GET_LOCK normal?

[Bryan McLellan]

On Thu, Dec 4, 2008 at 6:06 PM, Ruslan Zakirov <ruz at bestpractical.com> wrote:
> Could you check if ShowMessageStanza from 3.8 repository [1] improves
> situation? See also comments below.

> [1] http://svn.bestpractical.com/cgi-bin/index.cgi/bps/view/rt/3.8/trunk/share/html/Ticket/Elements/ShowMessageStanza

Installed this and restarted. Didn't change the time to load. Pretty
stable at just under 90 seconds for this ticket.

> Start from identifying where RT spends more time during the request.

Turned on 'debug' logging to a file. When loading this ticket I see
many lines like this:

[Mon Dec  8 23:37:12 2008] [debug]: We found a merged ticket.1721/1698
(/opt/rt3/bin/../lib/RT/Ticket_Overlay.pm:185)

After the first line, it will pause for one second, then print three
more of the exact messages at the same time with the same timestamp as
the first. Four messages every second for the 90 seconds it took for
the ticket to load.

After seeing this I opened up a few dozen tickets and watched the
debugging log. Every ticket without merges took under two seconds,
most of them a fraction of a second (short ones). Tickets with merges
took 50-110 seconds. Definitely looks like some sort of recursive loop
to do with parsing ticket merges.

Bryan