Redhat bugzilla is rediculously slow at times. Logins especially, any chance it could be updated or moved onto better servers which are as responsive as gnome bugzilla for instance?
Bugzilla does not cope well with large datasets. This is mostly due to some vastly inefficient SQL generated by search.pm. Add table-level locking into the mix and you've got an even bigger headache. Your main solutions will be in two areas. DB settings: - Shift as many tables as you can into innoDB. Its row-level locking will help a lot versus myisam. Note you'll have to keep myisam for full-text search of the comments table - Use a shadowdb host for searches. - Index everything - Boost your ram. - Watch for temp tables being written to disk. Code changes - search.pm has some very inefficient JOINs. - show the output of a search with added '&debug=1' to your friendly local dba. - keep your .js clean. you've got some runaway errors that seem to hork firefox pretty badly. - the groups code is horribly inefficient. it can add hundreds of permissions checks to the display of a single bug. Take a look at where you load is going, and if cpu is an issue. If you're seeing high perl and apache load, you might want to reconsider public access to charts.
Should be improved now. Closing.