Happy Cavity Day! (Oct 31 2007)


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Profile Matt Lebofsky
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Message 670156 - Posted: 31 Oct 2007, 21:37:15 UTC

Happy Halloween! We celebrated here in the Bay Area by having a 5.6 earthquake last night. No big shakes (ha ha) considering the relatively high magnitude. Anybody thinking Californians are crazy for living in such a seismic zone should remember the top two recorded earthquakes in the contiguous US were both in Missouri. I also grew up across the river from the Indian Point nuclear reactor, just outside NYC, which lies right next to a very active fault. Anyway...

Somebody complained about the weekly outage time notices on the web being off from reality. They are semi-automated, and one mechanism was created during PST and the other during PDT. As well, we haven't been sticking to exact times lately as we've come to rely heavily on BOINC's fault tolerance, i.e. if it's convenient to bring down servers a half hour early then it's no big deal - the clients should fail to connect and back off gracefully. So those messages are under the category of "vaguely informative" or "better than nothing" but at some point I'll tighten up their accuracy.

Jeff and I spent a chunk of time finally getting some reasonable load balancing to work such that we don't have to worry about feeder mod polarity issues (see older tech notes - basically round robin DNS doesn't work as expected and one server runs out of work faster than the other). We were lagging on this as actual requester IPs weren't showing up in the apache logs as the proxy was in the way. We discovered "mod_extract_forwarded" but we were using the wonderfully simple and effective "balance" utility which doesn't pass the expected "X-Forwarded-For" header to this module. Then I discovered "pound" which is like "balance" but does add the right headers to make this happen. Long story short: we're currently up with hopefully more equitable load balancing.

Outside of that: messing around with beta splitters again this morning (the beta project is mostly Eric's domain which I try to avoid as much as possible) to keep work generation going and test out the new splitter compile. And working on skymap stuff for public web consumption.

- Matt

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Profile Dr. C.E.T.I.
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Message 670197 - Posted: 31 Oct 2007, 23:21:52 UTC


Thanks for the Post Matt . .. and Happy Halloween to You Sir

. . . we need a DC Project to Predict Earthquakes around the Earth (sound familiar ;)


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Message 671091 - Posted: 2 Nov 2007, 11:29:40 UTC - in response to Message 670197.

. . we need a DC Project to Predict Earthquakes around the Earth (sound familiar ;)

There is one such (and probably a serious one) already comming, although no idea how soon will it be available.

Peter

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Message 671154 - Posted: 2 Nov 2007, 13:36:23 UTC - in response to Message 671091.

. . we need a DC Project to Predict Earthquakes around the Earth (sound familiar ;)

There is one such (and probably a serious one) already comming, although no idea how soon will it be available.

Peter


@ Peter - i am quite sure that it's a serious one . . . will have to impliment said Project here - on the East Coast (Carolina's - UNC etc . . .)

there's a Major FaultLine runnin' through the Carolina's and it's just a 'Matter of Time' before it strikes on a 'noticable' Richter Scale Rating - Best be prepared 'ere too . . .

richard


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John McLeod VII
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Message 671343 - Posted: 3 Nov 2007, 1:57:00 UTC - in response to Message 671154.

. . we need a DC Project to Predict Earthquakes around the Earth (sound familiar ;)

There is one such (and probably a serious one) already comming, although no idea how soon will it be available.

Peter


@ Peter - i am quite sure that it's a serious one . . . will have to impliment said Project here - on the East Coast (Carolina's - UNC etc . . .)

there's a Major FaultLine runnin' through the Carolina's and it's just a 'Matter of Time' before it strikes on a 'noticable' Richter Scale Rating - Best be prepared 'ere too . . .

richard


Actually, it is limited to laptops and some specially equiped desktops in California. Apparently the newer Laptops have accelerometers embedded in them to protect the disk. The project reads the accelerometers and reports the "strip" back to the project. It is also not even pre-alpha yet.
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Message 671468 - Posted: 3 Nov 2007, 4:51:12 UTC






> VibeHound Datalogger connected to the PC (computer's USB port and a LabVIEW driver) . . . well, you never know . . .

< as Carl's mentioned:

"The idea behind the project is that many new laptops (IBM Thinkpads and Apple Mac Power books / Mac Book Pro) have accelerometers built-in

for the protection of the hard drives (i.e. accelerometer detects that your laptop is falling so locks the hard drive). These detectors are sensitive enough for earthquake

detection, so we're hoping to get thousands of California laptops (and maybe desktops with an external USB accelerometer) for a wide-area distributed seismograph!"


> and you have to start somewhere eh . . . in So. California a number of us worked on quite a few different systems - looking for solutions to the Earthquake's Detection (Forecasting - per se)

someday - and i am sure sooner - than later - there shall be a solution . . .


richard

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