The SUMO site is sending all SELECT queries on the 'sessions' table to the master and not using the slaves. The slaves feel underutilized. This is leading to the master paging IT 3-5 times a day because it is bogging down with these queries. This is a large table, 1.7G, and the DB is not able to efficiently cache it in memory. Because of that, when enough of these queries come in, the disks hit 100% utilization, and the server performance bogs down for a few minutes. Would be great to get these queries split out to the slaves if we can. Thanks!
Component: Webdev → Knowledge Base Software
OS: Mac OS X → All
Product: mozilla.org → Sumo
QA Contact: webdev → kb-software
Hardware: PC → All
Version: other → unspecified
Going to try to get these into Tuesday's code freeze.
Target Milestone: --- → 0.6
Can I mark this blocking? Getting wake up pages on this blows.
Target Milestone: 0.6 → ---
You can, but it won't go out tonight, 'cos if I make a change like this without QA to tonight's push Justin's head will explode.
Created attachment 327704 [details] [diff] [review] Force ADODB to use slaves for this query. I feel there has to be a less hackish way than this, but it works.
Attachment #327704 - Flags: review?(nelson)
Comment on attachment 327704 [details] [diff] [review] Force ADODB to use slaves for this query. let's get this staged
Attachment #327704 - Flags: review?(nelson) → review+
Thanks for committing Nelson!
Status: NEW → RESOLVED
Last Resolved: 10 years ago
Resolution: --- → FIXED
I don't think this one should be upstreamed as issue 448497 reverts it. Also, memcache can now be used for sessions.
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