Technical news, and SETI@home daily stats for 29.06.2007.

[Rattledagger]

Mod Oddity (Moddity?) (Jun 28 2007)

So there have been complaints that while people have been able to connect to our schedulers, they sometimes aren't getting work ("no work to send" messages, etc.). I checked the queues, and there's continually 200K results ready to send out. I checked the httpd processes/feeders on bruno and ptolemy - no packets being dropped, and the feeders (at the time I checked) were filling their caches at the normal rate. All other queues (including transitioner) are empty or up-to-date. So what's the deal?

Well, we are splitting the feeder onto two servers via a mod clause (id % 2 = 0 or 1, depending on the machine). I checked to see if there was any disparity in the counts of results ready to send based on this mod.

First, here's the current total count of results ready to send:

mysql> select count(id) from result where server_state = 2;
*************************** 1. row ***************************
count(id): 210172

Now check out the vast difference between id % 2 = 0 or 1:

mysql> select count(id) from result where server_state = 2 and id % 2 = 0;
*************************** 1. row ***************************
count(id): 1051

mysql> select count(id) from result where server_state = 2 and id % 2 = 1;
*************************** 1. row ***************************
count(id): 209121

??!? This means that, effectively, the "odd" scheduler has a queue of 200K results ready to send, the "even" has close to zero. Even weirder is that complaints I read have mostly been that users are only able to get even ID'ed results but not odd, which leads me to believe this disparity "switches poles" every so often.

This isn't any kind of major catastrophe (as evidenced by stable active user count and good traffic graphs). I'm also guessing this has been aggravated by me lowering the queue ceiling to 200K (at 500K there was probably enough work in both even/odd queues at any given time). Still the question remains: what's causing such a wide disparity? Interesting...

Now that I think about it.. this may simply be an artifact of how round robin DNS works, mixed with the mysterious behavior of libcurl and windows DNS caching. In any case, when we get multibeam on line there will be twice the work to send out and this minor problem will probably disappear.

[EDIT: In other threads you'll see that this very concept was already touched upon elsewhere by some knowledgeable folks. Credit where credit is due...]

In other news...

Finally got server "bane" on-line acting as a third web public web server. Fairly straightforward, though I still have some cleanup to do involving that. This may very well become to sole web server shortly and we can then retire both kosh and klaatu.

I'm writing this tech news item early as I have a meeting later involving university bureaucracy. Fun.

- Matt

#____Total Work Done____Todays WD_____AWD________overtake_______Team-name
01______285.708.960______616.753______635.200______impossible______SETI.USA
02______244.949.636______403.705______372.169______impossible______SETI.Germany
03______102.195.017______122.831______108.472______impossible______BroadbandReports.com Team Starfire
04______100.141.286______278.496______250.815______impossible______L'Alliance Francophone
05_______87.807.970______167.439______152.205______impossible______BOINC Synergy
06_______84.489.786______116.505______103.603______impossible______Czech National Team
07_______74.089.967______122.502______119.866______impossible______SETI@Netherlands
08_______53.619.642______199.162______198.579______impossible______The Knights Who Say Ni!
09_______44.059.501_______15.296________7.963______impossible______OcUK - Overclockers UK
10_______32.773.411_______93.321_______85.608______impossible______Team Art Bell
11_______32.750.369_______80.668_______60.023______impossible______Overclockers.com
12_______32.424.178_______10.859________4.639______impossible______BOINC.Italy
13_______28.717.982_______59.651_______61.480______impossible______Team 2ch
14_______23.667.944_______68.532_______56.398______impossible______The Planetary Society
15_______18.108.465_______95.303______102.215______impossible______Team MacNN
16_______16.747.340_______38.333_______23.378______impossible______Ars Technica
17________3.781.060_______28.017_______27.004______impossible______Universe Examiners
18_______52.872.462_______62.991_______63.724______notanoption_____TeAm AnandTech
19_______-1.419.769_______22.925_______18.385_________77 days______Phoenix Rising
20_______-3.610.117_______65.562_______50.823_________71 days______SETI@Taiwan
21_______-8.544.386_______66.197_______67.097________127 days______Team Starfire World BOINC
22_______-9.700.664_______11.879_______10.498________924 days______Hewlett-Packard
23_______-9.957.335_______68.109_______59.485________167 days______SETI@China
24______-10.429.461________5.168_______-1.378______impossible______Amateur Radio Operators
25______-11.088.089_______24.157_______11.751________944 days______PC Perspective Killer Frogs
26______-11.696.667_______18.939_______11.502______1.017 days______Canada
27______-12.229.127_______53.217_______57.779________212 days______Dutch Power Cows
28______-12.690.136______-35.957______-34.498______impossible______Planet 3DNow!
29______-13.881.281______-20.501______-23.441______impossible______2CPU.com
30______-15.039.159________2.157_______-1.645______impossible______Team MacAddict
31______-16.179.893________1.691________1.071_____15.107 days______Team NIPPON
32______-18.369.155_______-5.569_______-9.027______impossible______BOINC SETI@home RUSSIA
33______-18.656.578_______-6.007______-10.828______impossible______BOINC@Denmark
34______-19.383.095________8.041__________260______74.550 days______Hungary
35______-19.572.910______-20.889______-25.796______impossible______Portugal@Home
36______-20.579.853_______25.092_______22.557________912 days______UK BOINC Team
37______-21.290.971______-44.758______-48.249______impossible______Picard
38______-21.934.039_______47.250_______33.533________654 days______US NAVY
39______-22.436.577______-43.082______-41.967______impossible______LittleWhiteDog
40______-23.697.664_______26.132_______19.386______1.222 days______BOINC@AUSTRALIA
41______-24.183.639________8.268_______-1.591______impossible______U.S.Air Force
42______-24.449.228______-13.494______-16.484______impossible______SETI@klamm.de
43______-24.931.062_______13.025________5.779______4.314 days______SETI.hr
44______-25.064.839______-22.458______-23.767______impossible______Team EDGE
45______-25.551.262______-20.289______-24.524______impossible______HispaSeti & BOINC
46______-27.199.551______-25.686______-29.912______impossible______SETI Sverige [Sweden]
47______-28.679.803______-34.338______-29.391______impossible______BOINC UK
48______-29.459.570_______-1.398________1.157_____25.462 days______AUSTRIA - NATIONAL - TEAM
49______-29.807.847_______-4.242______-13.348______impossible______BOINC.SK
50______-30.068.226______-27.286______-32.211______impossible______SETI@Home Poland

Appart for Anandtech's stats, it shows how much more/less than Anandtech.
Also shows based on Average Work Done how many days for Anandtech to overtake the team, or be overtaken by a team behind

 

[BlackMountainCow]

Thx for the stats RD!

I guess if I had that much trouble maintaining my PCs as the SETI guys have, I'd have quit DC long time ago ...

 

[Assimilator1]

It might be a lot easier if they just ran it off 1 or 2 PCs

Thx RD

And lol at last news line

 

[petrusbroder]

Thanks for the news and stats, Rattledagger.