Even wat oude stats inhalen...
Helaas is er eigenlijk niets om in te halen, dus ik presenteer u driemaal statsloze stats.
Happy New Year from SETI@home
Thanks again for another year of generous support for our project! We couldn't do this without everybody's help. Onward to 2011...
29 Dec 2010 20:25:17 UTC
Bij gebrek aan stats dan maar wat nieuws hier neerzetten. Vulling is tenslotte vulling
29 Dec 2010 21:18:22 UTC
Last post of the year!
I understand the SETI@home/BOINC back-end is a bit confusing. I think there are only a handful of people who understand all the relationships between every step of the BOINC finite state machine, the SETI@home data pipeline, and every server in our closet. I can only really scratch the surface of these details during these relatively pithy missives.
So let me try my best to quickly answer the general question: "did those two brand new servers (oscar and carolyn) help?"
First of all, there are about 100 known problems with our systems at any given time. Most of these are low priority and "time out" on their own. There are still a bunch of high priority issues, of which these new servers addressed *some*.
One easy problem to fix was replacing mork (the randomly crashing master mysql database server) with carolyn. This has been great... and I think we just (as of this morning) solved the current batch of disk i/o problems (by properly tweaking the write cache settings). Carolyn also has a lot more disks and memory than mork had, so there's still a lot of room to grow as needed.
The other new server, oscar, is taking care of two major problems. First, the science database on thumper was abysmally slow - so now this is on oscar. That's great, however it's not running as fast as we'd like. We still haven't fully benchmarked this, though. Maybe at worst we'll need to add more disks to the system - we shall see. The second major problem oscar is helping to resolve is ptolemy - our internal administrative file server - which, like mork, also randomly crashes from time to time locking everything up. Now that thumper is off the hook as a science database server, it can take over and easily handle ptolemy's current functionality, and then we can retire ptolemy. There's actually a third minor problem that's also getting fixed: thumper's root partition is on a messed-up software RAID device which kinda works but has been scaring us for way too long. It'll be great to have this server-shuffle opportunity to have a quiet moment to reinstall the OS on thumper and fix that RAID.
But that's pretty much it for now. Other major problems exist with no clear solutions. In fact, many of them are data driven, or network infrastucture driven, and therefore out of our sysadmin hands - no server upgrades will solve them.
That said, I hardly want to sound hopeless (and definitely not ungrateful). We're pros at working through our various struggles, and gaining oscar and carolyn has been the largest improvement in years, with still more benefits to come as we get rolling full bore in the new year and more aggressively shake out the remaining configuration problems. Plus a third new donated server (synergy) is coming down the pike, which we'll use to address other current shortcomings. When oscar, carolyn, and synergy are all being used to their fullest potential (a month or two from now?) let's revisit what our biggest system needs are. It may very well be that these new machines did in fact shake out the bulk of our current issues, and we'll be in good shape for years to come.
Happy new year! May we have actually publishable results in 2011 - positive or negative I don't care - it's science either way. We certainly could stand to get something meaningful in the journals concerning all the data we've been reducing for 11 years.
- Matt
27 Dec 2010 22:00:31 UTC
Ah, the few days back at the lab between Xmas and New Year's... The university assumes nobody works at this time, so the buses aren't running, and so I have to drive into the lab. But of course they are still handing out parking tickets to people without regular parking permits (like myself, who rarely drive to the lab). So I gotta park elsewhere. Anyway...
Except for bruno (the upload server) having fits we were pretty much running smoothly all weekend. However bruno is also the main BOINC back-end administrative server for the SETI@home/Astropulse project, so when it has fits, everything kinda gums up. We couldn't get into bruno remotely (full process table?) so it waited until this morning when Jeff got in and rebooted it.
There was some cleanup after that, and we seemed out of the woods, but we're still having these mysql issues where the database enters these long periods of flushing pages to disk. We all agree that this is largely due to the increased demand (after all the long/short outages over the past two months, and perhaps a bout of short runners). Increased demand means more deltas, which in turn means more fragmented pages. We have these weekly outages to defragment the database, but given the load it's like 3-4 weeks of fragmentation within one week. We're thinking the outage tomorrow will largely fix this, but we're still tuning other stuff in the meantime. We already gave mysql access to more memory, but Bob predicted this wouldn't help, and he was right. He's trying other stuff now.
So the plan is to hang on have just the normal outage tomorrow, then be up (as best we can) the rest of the week and throughout the New Year's Eve weekend. Then in the new year we can really start squeezing these new servers and see what they got.
Oh yeah - I turned off the "resend lost results" for now to reduce the load on mysql. This is temporary.
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Ouwe troep? Wat is dat?.......Alles is leuk, zelfs modelracing..........BOINC ook mee met DPC!
......Team Grazzie~Power....!! Mooooooeeeee......
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Welkom Martijn1234 
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