Volgens mij zijn we vorige week helemaal 't nieuws vergeten..
12 Jan 2012 | 21:01:42 UTC
Hello people. I'm actually about to head out again shortly (once again for a whole month) so let me get y'all caught up before I disappear.
Let's see. There's been a lot of the usual hiccups over the past couple of weeks. Overloaded servers locking up and requiring a hard restart, drives failing and being replaced, bringing machines down on purpose to upgrade the OS, etc. No singular event was tragic or noteworthy, but the quantity of such events has been slightly higher than normal.
Meanwhile various projects have been pushing along. After enough analysis, database tweaking, and data dumping/reloading, we finally created some test "small signal tables" containing the top 1% signals on which to do our final analysis. Turns out doing the same on the 100% full (and constantly growing) tables was a performance disaster. Basically we're now determining what our i/o needs and parameters are with much smaller cases, and then going from there. Right now the signal tables entirely fit in memory, but part of this equation is adding more spindles to the science database array to improve disk i/o as well. This is where the GPU User's Group-donated JBOD comes in. More on that below.
Another project I've been working on is to get the splitters (the programs that make workunits out of raw data) to become sensitive to VGC (voltage gain control) values available in the raw data headers so that we can avoid splitting areas with low VGC values (and therefore loud noise). In layman's terms: we're trying to set everything up to automatically reject noisy workunits before sending them out. We know one or two beams (out of fourteen) are sometimes flaky, and keeping those workunits out of the pipeline will help reduce network competition for downloads.
This should have been fairly straightforward, however during the course of testing we're finding more than one or two beams with various problems. More like 5 or 6. This may be for several different reasons, including bogus or misreported VGC values. This is on a front burner, with several parties involved here and at Arecibo.
Speaking of network competition - yes, we're away that we are dropping all kinds of connections during uploads/downloads. This isn't because of our router (which was definitely the problem over the summer before we added RAM to it), but somewhere else further up the pipeline. Still figuring this out, but it's certainly load related.
Hardware wise, we took an archive server out of the closet to make way for the JBOD mentioned above. The archive server will move into our secondary lab down the hall (where other servers currently reside). We were going to install the JBOD on Tuesday but the hole in the rack made for it isn't big enough to let us mess with internal cabling. Given that we hope to hook this up to at least two separate servers, we'll likely need to mess with internal cabling. So we're going to try to do our best with that while the JBOD is still on the table in our lab.
Oh yeah.. our web server crashed due to overloading last Friday, likely due to an article Andrew published about recent Kepler analysis results. He didn't clearly enough state that these plots were radio frequency interference, and thus we got clobbered due to confused news reports that we found ET. The usual drill, basically. The text of the article was cleaned up. Eric suggested we put disclaimers on the top of every web page on our site that says, "everything we find is Radio Frequency Interference unless we specifically tell you otherwise."
Okay. I should wrap this up. As a parting gift here are a couple random recent photos:
Here's the new JBOD, as seen from behind, sitting on our lab table. There's only 21 (currently empty) drive bays back here, but on the front there are 24 full ones in front.
Here's the current state of our server closet across the hall. Note the hole in the middle rack - that's where the JBOD is going.
And for fun, last week I shot this photo, which is the entire Bay Area consumed in fog, which we at the lab (over 1000 above sea level) are enjoying lovely weather over said fog.
Wow those pictures are blurry. Well, it's from my iPhone 3GS. Not exactly state of the art.
So! I'm now official on the road. I'll be playing with my band MoeTar in Whittier, California on Saturday (opening up for the Allan Holdsworth Band), then I drive up to Seattle to meet some of the guys in Secret Chiefs 3, and then we all drive in the tour van to Denver, where we meet to remaining guys (flying in from NYC and Sydney, Australia). We'll rehearse two days, then tour for a few weeks all over the western US (with one stop in Vancouver), co-headlining with the awesome band Dengue Fever. Should be fun!
Cheers,
- Matt
Ouwe troep? Wat is dat?.......Alles is leuk, zelfs modelracing..........BOINC ook mee met DPC!
......Team Grazzie~Power....!! Mooooooeeeee......
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Is Nederland in de persoon van Christian Kist wereldkampioen darten! 
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