Starving Feeder (Feb 07 2007)

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Profile Matt Lebofsky
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Message 514730 - Posted: 7 Feb 2007, 23:33:31 UTC

Eric, Jeff, and I were in the same room together for an extended period of time for the first time in weeks, so we had a code walkthrough this morning and database correction code. What does this mean? Basically, with all the different SETI@home clients over the years (classic, BOINC, enhanced, and all minor versions within), we have had various bugs (or features) which resulted in signals with varying minor issues in what is now our unified master science database. All the data are valid - I hope there will be more verbose text about this cleanup procedure at a later date. Anyway, this morning we walked through a program (mostly written by Jeff) to unify all the signals so future analysis will be much, much easier. Minor edits and major testing will have to happen before we run this on real data. I only mention this in case anybody was worried that all we do all day is put out server fires and nothing scientifically producive. We also had a science meeting where we discussed, among other things, our current multibeam data pipeline - we're have been successfully collecting data from the new receiver for months, and we're really close to sending this data out to our volunteers.

As for the project going up/down. Well, right after my last note I went to sleep with the servers happily recovering, but then we hit that same ol' database problem (slow feeder queries gumming up the works). We battled that all day, tweaking this parameter and that, dropping a deprecated index, restarting the database over and over and checking its I/O stats... Nothing really obvious came to light, but Bob configured the database to make it less like to try to flush modified pages in memory to disk, and that seems to be working for now. All the other problems mentioned yesterday are no longer problems.

- 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

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Josef W. Segur
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Message 514772 - Posted: 8 Feb 2007, 2:25:36 UTC - in response to Message 514730.

...
As for the project going up/down. Well, right after my last note I went to sleep with the servers happily recovering, but then we hit that same ol' database problem (slow feeder queries gumming up the works). We battled that all day, tweaking this parameter and that, dropping a deprecated index, restarting the database over and over and checking its I/O stats... Nothing really obvious came to light, but Bob configured the database to make it less like to try to flush modified pages in memory to disk, and that seems to be working for now. All the other problems mentioned yesterday are no longer problems.

- Matt

The Cricket graph is certainly looking normal now, thanks.

Seti Beta/Astropulse is still down, though. Just thought I'd mention it, there have been occasions in the past on which that had simply been forgotten in the scramble to get the main project functions working.
                                                             Joe

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Message boards : Technical News : Starving Feeder (Feb 07 2007)


 
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