[rt-users] RT Slow to add and remove group members

Ruslan Zakirov ruz at bestpractical.com
Mon Dec 13 20:39:34 EST 2010

On Tue, Dec 14, 2010 at 12:27 AM, Todd Chapman <todd at chaka.net> wrote:
> Our production RT instance (3.6.3 - old, I know) takes a really,
> really long time to add and remove group members.
> Our database is MySQL and the CachedGroupMembers table has the index:
> KEY `CachedGroupMembers3` (`MemberId`,`ImmediateParentId`)

I recall that index on Via is relevant for the shredder, so may be
it's also relevant for removing a member as it also means dropping
records. Without full SQL log it's hard to say. It's better to write a
script that adds a user to a group and deletes him right after. Use
this script to collect all queries with hi-res timings. All queries
required to see queries that are executed many times even if those are
quite fast.

> What can we do to improve the situation (yes, I would be upgrading if
> that were possible at the moment)?
> Would running shrink_cgm_table.pl be a good idea?

Shrinking would make lookups faster. Let's say 30% faster as table
gets ~30% smaller. As far as I know there is no harm in running it on

> Thanks!
> -Todd

Best regards, Ruslan.

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