Cleo (Apr 08 2009)

Message boards : Technical News : Cleo (Apr 08 2009)

Author	Message
Matt Lebofsky Volunteer moderator Project administrator Project developer Project scientist Send message Joined: 1 Mar 99 Posts: 1375 Credit: 74,079 RAC: 0	Message 883493 - Posted: 8 Apr 2009, 20:00:28 UTC
	The science database choked last night. Nothing terrible - it was just unable to deal with the pulse index rebuilds as well as the usual outage recovery. So the assimilators got a little hung up for a while until the current index build was finished. It's still a mystery why this was as big an issue as it was - we've built indexes before on live, fully functional databases. Hmm. Apparently we have to be a little less cavalier about it. Turning off a server for good always has unintended consequences. Shutting down milkyway yesterday caused mail from the web server to fail. A couple red herrings later I found the problem - the milkyway mail server replacement (clarke) wasn't configured to allow relaying from the web server machine. Easy squeezy problem to fix. Now reset password requests, forum moderation notices, private message alerts, etc. are being sent. Spent way too much time hunting down the cause of a seg fault in my NTPCker web page code. It's kinda hard when it's a C program that's being executed within a c-shell script, which in turn is being called by a php script, and which is all running under apache. It's frustrating when everything works on a command line, but not within apache. Anyway I finally figured it out, or at least got it working. The irony is this code was to produce a tiny close-up waterfall plot around any given signal (to immediately spot symptoms of RFI), and once it was running Jeff and I realized our database query logic was slightly wrong, and the correct logic would take too long to be of any use in a dynamically generated plot on the web anyway. Sigh. Looks like we'll have to batch job it or something like that. - 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: 883493 ·

DJStarfox Send message Joined: 23 May 01 Posts: 1040 Credit: 485,117 RAC: 71	Message 883585 - Posted: 9 Apr 2009, 0:28:13 UTC - in response to Message 883493.
	Having an approximation (plot) on the web would be fine, unless you want a table of values. Then, you're right: do the query offline and later have results on the web just read answers from a summary table.
	ID: 883585 ·

[KWSN]John Galt 007 Volunteer tester Send message Joined: 9 Nov 99 Posts: 2439 Credit: 16,594,037 RAC: 0	Message 883613 - Posted: 9 Apr 2009, 2:22:55 UTC
	That dang clarke...gave me problems also... More of the noise and power requirement type... Glad to see the old boy up and running!!! ____________ Clk2HlpSetiCty:::PayIt4ward
	ID: 883613 ·

KWSN THE Holy Hand Grenade! Volunteer tester Send message Joined: 20 Dec 05 Posts: 1594 Credit: 4,423,503 RAC: 4,193	Message 885131 - Posted: 13 Apr 2009, 22:42:39 UTC Last modified: 13 Apr 2009, 22:43:30 UTC
	Query - if the pulse database is re-built, why does the Science page state that there's been -506m pulses in the last 24 hrs? ____________ .
	ID: 885131 ·

Virtual Boss* Send message Joined: 4 May 08 Posts: 410 Credit: 5,807,930 RAC: 417	Message 885284 - Posted: 14 Apr 2009, 10:18:10 UTC - in response to Message 885131.
	Query - if the pulse database is re-built, why does the Science page state that there's been -506m pulses in the last 24 hrs? Maybe ET(s) stole all the pulses to try to stop us finding him/her/it/them.
	ID: 885284 ·

Andy Lee Robinson Send message Joined: 8 Dec 05 Posts: 615 Credit: 36,745,827 RAC: 1,900	Message 885715 - Posted: 16 Apr 2009, 3:23:24 UTC - in response to Message 883493.
	Matt, are you making any use of memcached? Read-caching queries is one of its excellent uses. If you have a lot of cacheable queries, you may be able to drastically reduce QPS on the database. If you give that query an hour lifetime, then it'll behave like an offline query with an occasional unlucky person having to wait a few more seconds for the result. The cache memory can be automatically distributed among available servers too.
	ID: 885715 ·

arkayn Volunteer tester Send message Joined: 14 May 99 Posts: 3088 Credit: 40,276,401 RAC: 65,408	Message 885826 - Posted: 16 Apr 2009, 16:35:18 UTC
	I am guessing that Matt is taking a week of vacation. ____________
	ID: 885826 ·

pixzy Send message Joined: 7 Jun 99 Posts: 103 Credit: 2,907,098 RAC: 956	Message 885844 - Posted: 16 Apr 2009, 17:33:30 UTC - in response to Message 885826.
	So it would seem... ____________
	ID: 885844 ·

kenzieB Volunteer tester Send message Joined: 16 Mar 07 Posts: 3913 Credit: 1,576,197 RAC: 566	Message 885872 - Posted: 16 Apr 2009, 19:18:23 UTC Last modified: 16 Apr 2009, 19:18:51 UTC
	A well earned vacation. ____________
	ID: 885872 ·

Message boards : Technical News : Cleo (Apr 08 2009)