Message boards :
Technical News :
Slow Going (Feb 07 2008)
Message board moderation
Author | Message |
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Matt Lebofsky Send message Joined: 1 Mar 99 Posts: 1444 Credit: 957,058 RAC: 0 |
We're having little luck getting science database thumper to perform up to expectations. We determined the fact it is both a database and raw data storage server isn't really the problem - the database alone is somehow constrained. Is it all the additional indexes we added recently? Extra load due having to make logical logs for the replica? Something else entirely? Of course, while testing/tweaking the OS root mirror drive on thumper failed. We got the notice from smartd but mdadm didn't notice, which was scary. We manually failed the mirror and brought in the hot spare which is sync'ing up now. Anyway.. the assimilator queue is growing and there doesn't seem to be much we can do about it now, at least anything drastic given it's the end of the week. We are sending out a lot of short work - maybe this will change soon and give us some relief. Other small news: recent splitter updates include (a) more realistic deadlines, i.e. they have been reduced 25%, and (b) radar blanking code - we're testing that now. There also has been a little bit of scheduler/upload server choking due to the aforementioned headaches - including one of the schedulers running out of work (as it runs faster than the other and therefore its queue depletes faster). Once again, we're have little choice but to wait out the storm. - Matt -- BOINC/SETI@home network/web/science/development person -- "Any idiot can have a good idea. What is hard is to do it." - Jeanne-Claude |
Dr. C.E.T.I. Send message Joined: 29 Feb 00 Posts: 16019 Credit: 794,685 RAC: 0 |
Well - definetly a lot goin' on eh . . . Thanks for the Post Matt You do an excellent job @ keepin' us informed eh . . . BOINC Wiki . . . Science Status Page . . . |
SATAN Send message Joined: 27 Aug 06 Posts: 835 Credit: 2,129,006 RAC: 0 |
We know you do your best. Their is nothing more you can do with what you guys have at your disposal. |
DJStarfox Send message Joined: 23 May 01 Posts: 1066 Credit: 1,226,053 RAC: 2 |
Good news on the splitter updates. I think 25% was a good choice and a modest decrease that will help everyone long-term. The radar blanking will be a HUGE help! As far as the database, adding indexes helps SELECT speed but will hurt UPDATE/INSERT/DELETE speed as more indexes are added. It's a trade-off. I've seen databases that use a separate RAID for indexes to try to help the bottleneck. Whatever it is, I'm sure you'll figure it out. Watch out for any large sort or large table scan operations--performance killers. Just yesterday I figured out how to detect SMART status of a drive attached to a 3ware RAID controller (in linux). And it will email me of any trouble. Now I can relax. :) If I could only figure out a way to get hddtemp to also read those drives. I can get smartctl to display the attributes... PS Work is coming through. A little delay is fine with me. :) |
Richard Davenport Send message Joined: 1 Feb 02 Posts: 1 Credit: 475,284 RAC: 0 |
I have been having trouble downloading the workgroups. I don't know if it is my computer, or something else. |
Choldar Send message Joined: 3 Jan 08 Posts: 1 Credit: 1,651,904 RAC: 0 |
Hi, similar to above, I can't get new work, nor can I send the 9 completed tasks that I have. I had a look at the server page and apart from one server in a disabled state, everything else was running fine. I don't know if its a continuation of your post, Matt, but yeah... just thought I'd check in. Great job with the news updates. Thanks! |
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