[rt-users] Is this slow? It seems slow.

[Jamie Wilkinson]

This one time, at band camp, Val Luck wrote:
>As it is right now with testing (creating tickets, re-assigning them, resolving them, etc) I can get up to a 5 to 15 second delay when going from "display" to "jumbo" mode.  

And similarly when clicking on Update from the front page, or
Resolve/Comment/Reply on the Display page.  Yes, this behaviour has been
seen in the past.  version 3.0.3pre2 of RT with a recent version of
DBIx::SearchBuilder (now 0.86) has fixed the speed problem for some people.
Unfortunately, I am not one of them.  My experience - 3.0.0 and 3.0.1 ran
dog slow, 3.0.1 with a 0.83_01 of DBIx::SearchBuilder ran faster, but page
loads were still taking about 30 seconds for the above operations, and now
with 3.0.3pre2 and DBIx::SearchBuilder 0.86 I am again experiencing 20
minute database queries.

>This seems kind of slow, doesn't it?  What will happen when 5 people are beating on it?  

postgres will fork a subprocess for each query, so that when 5 people are
doing things, you'll have 5 processes taking up about 20% CPU each.  And
when you hit the stop button, the subprocess won't stop.

>While clicking around in RT, it's common for the postgres db process 'postmaster' jump to 100% and sit there for the duration.  Additionally, I saw an earlier message posted about adding indexes to the RT database.  I had assumed that he was doing custom queries..?  Are their any extra indexes we could(should) add that are sanctioned by the RT programmers/DBAs that could speed things up?

I've added some indexes to a few tables, but in the mists of time and
experimentation, have forgotten which ones they are.

Turn on postgres logging (log_statements = true; syslog = 2 and so on) and
you'll see the large ACL query run for a while.  Copy that into psql and run
it yourself with "explain analyze" prepended, and you'll have some profiling
information you can use to work out the problem.

I'll be doing that mysel shortly, but it would be useful to have more than
one explain to help debug it.

-- 
jaq at spacepants.org                           http://spacepants.org/jaq.gpg