Semi Solutions (Jun 08 2009)

Message boards : Technical News : Semi Solutions (Jun 08 2009)
Message board moderation

To post messages, you must log in.

AuthorMessage
Profile Matt Lebofsky
Volunteer moderator
Project administrator
Project developer
Project scientist
Avatar

Send message
Joined: 1 Mar 99
Posts: 1444
Credit: 957,058
RAC: 0
United States
Message 905295 - Posted: 8 Jun 2009, 21:31:03 UTC

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
-- BOINC/SETI@home network/web/science/development person
-- "Any idiot can have a good idea. What is hard is to do it." - Jeanne-Claude
ID: 905295 · Report as offensive
Richard Haselgrove Project Donor
Volunteer tester

Send message
Joined: 4 Jul 99
Posts: 14674
Credit: 200,643,578
RAC: 874
United Kingdom
Message 905308 - Posted: 8 Jun 2009, 22:44:49 UTC - in response to Message 905295.  

... the increased active user load ...

Be careful what you wish for ;-)

Thanks for the update, as always.
ID: 905308 · Report as offensive
Profile Andrew Clayton
Avatar

Send message
Joined: 12 Apr 99
Posts: 7
Credit: 907,810
RAC: 0
United Kingdom
Message 905318 - Posted: 8 Jun 2009, 23:14:59 UTC

I wonder if you use, or have thought about using memcached?

http://www.danga.com/memcached/


ID: 905318 · Report as offensive
Profile Gary Charpentier Crowdfunding Project Donor*Special Project $75 donorSpecial Project $250 donor
Volunteer tester
Avatar

Send message
Joined: 25 Dec 00
Posts: 30929
Credit: 53,134,872
RAC: 32
United States
Message 905319 - Posted: 8 Jun 2009, 23:15:46 UTC

thanks for the update


ID: 905319 · Report as offensive
Profile Rick

Send message
Joined: 27 Mar 01
Posts: 8
Credit: 25,223,770
RAC: 0
United States
Message 905479 - Posted: 9 Jun 2009, 12:21:47 UTC

Good work over the weekend. If I'm reading right, we've got some AP work on the way. Good news for sure.

ID: 905479 · Report as offensive
Profile Andy Lee Robinson
Avatar

Send message
Joined: 8 Dec 05
Posts: 630
Credit: 59,973,836
RAC: 0
Hungary
Message 905502 - Posted: 9 Jun 2009, 13:47:41 UTC - in response to Message 905318.  

Yes, I was going to suggest memcached too - it can cache queries and any other serializable objects, and act as volatile network-shared memory - great for php session handling across multiple webservers, and an essential addition to the LAMP arsenal.
ID: 905502 · Report as offensive
Profile KWSN THE Holy Hand Grenade!
Volunteer tester
Avatar

Send message
Joined: 20 Dec 05
Posts: 3187
Credit: 57,163,290
RAC: 0
United States
Message 905848 - Posted: 10 Jun 2009, 17:24:07 UTC

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

Hello, from Albany, CA!...
ID: 905848 · Report as offensive

Message boards : Technical News : Semi Solutions (Jun 08 2009)


 
©2024 University of California
 
SETI@home and Astropulse are funded by grants from the National Science Foundation, NASA, and donations from SETI@home volunteers. AstroPulse is funded in part by the NSF through grant AST-0307956.