Semi Solutions (Jun 08 2009)

Dan and company are wrapping up their work at Arecibo and heading home today (I think). It was a painful weekend trying to get our data recorder working again (and installing the new SERENDIP V data recorder) but all is well, more or less. We even did some observations of the crab nebula (and its known pulse) which Josh then found in the data using Astropulse, providing a good end-to-end test. We'll send workunits using that data once we get that raw data up here. We ultimately found our SATA drive enclosures were a major part of the headache, and we're planning to replace those with USB enclosures... probably.

It was a painful weekend network-wise - the increased active user load (mixed with the lack of long Astropulse workunits to send out) means a lot more activity on the result table in the database, which means periods of mysql choking. We're adjusting some code to do "dirty reads" which may help conserve resources. For example, the count of the result table to determine the current size of the ready-to-send queue doesn't have to be 100% accurate, so locking the table to do such a query is overkill. We'll see if that works, or helps.

We hope to replace these database servers, or at least the mysql replica, with one of these new Intel servers. They have tons of CPUs and gobs of memory, but the disk controller doesn't work. Actually, that's unclear - we replace the card with one we know works, and that wasn't behaving either. Until we can figure that out we're stuck with what we got.

- Matt
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-- BOINC/SETI@home network/web/science/development person
-- "Any idiot can have a good idea. What is hard is to do it." - Jeanne-Claude

... the increased active user load ...

thanks for the update


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... from the thread title, I expected something involving big rig trucks!... ;-)
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