|
 Burning CPU Cycles         \       /            _\/_
 For Sun and Profit           .-'-.              //o\  _\/_
                         --  /     \  --           |   /o\\
 ^~^~^~^~^~^~^~^~^~^~^~^~^~^-=======-~^~~^^~~^~^~^~|~~^~^|^~
       How To Compute Four CPU Years in One Day          |
               with Dan, Flo, and Rob








Background:
 - EngineYard Hash Challenge
 - Generate SHA1 sums close to a given Hash
   (Hamming Distance)
 - Submit via Twitter




Solution
 - Distributed stateless client + collecting servers
 - Randomized Starting Point
 - Find a free CPU, throw a client on it
 -> Safe against reboot, restart, HDD fail,
    heterogeneous CPUs (speed, arch, os)
 - Re-Deployment automated

 - Between 1 and 3 M hashops/sec




Alternate Solutions:
 - CUDA -- harnessing the power of GPUs
   (reported up to 200 M hashops/sec)
 - JavaScript web site
   (200-500 hashops/sec)


Hosts:                  372
IPs:                    327
pids:                24 188
hashops: 89 195 441 700 517  (89 trillion)
cpusecs:        125 125 252  (3.97 cpu years)




Challenge phrase
"I would much rather hear more about your whittling project"

Our best yet illegal result (dist=33):
"FiXTUrE rfC959 dEFecT BDd MD5 sERvlETs DElEGATE"

seibert's best result for long time (dist=31):
"LehEy LENGtH layoUt liB liGhTTpD liFo lISp lIBRARy LInk LIBcRYpt LesS lAYER =@zT="

Our  SHA1: 3a19c487e75f300b327bce4273d0088aa6fbb181
Orig SHA1: 1249c4b7f578204f10798c0269f8488280fb9981
Best SHA1: 0958c0b7f7f8a06690ddd44268f841fba8fb9981






Lessons Learned:

- Read Rules
- Read Rules twice
- Read Rules again

- Client needs to send pings to show he's alive
- Server needs to signal client
   * Latest Client Version
   * End of competition
   * ACKnowledge receive
- Standardize Time Zones (UTC, CEST...)
- Unique Names for Log Files (host, time)
- Admins are interested in their best result (improve logs)









                                  ..-^~~~^-..
                                .~           ~.
                               (;:           :;)
                                (:           :)
                                  ':._   _.:'
                                      | |
                                    (=====)
                                      | |
-O-                                   | |
  \  <== Florian                      | |
  /\              Login-server ==> ((/   \))
    

Don't use random servers you have a login from 'old times'
without officially asking, if there is a change the admins 
get your 'Do you want to participate' - email with your
name....

-----------------------------8<----------------------------
Hallo Florian,

......... wies mich vorhin auf Deine Nachricht hin, ich
komme aber erst jetzt dazu, sie zu lesen und jetzt wird
mir einiges klar ...

On Tue, 21 Jul 2009, Florian Streibelt wrote:
> > ich nehme hier zusammen mit zwei Komilitonen an einer 
> > sha1-Challenge teil

wir haben heute morgen mehrere Instanzen von parallel_run.sh
auf unserem Login-Server gekillt, die dort für erhebliche
Last sorgten. 
(Ich hoffe, dass hat Euren Rekordversuch nicht wirklich
beschädigt).
Ich nehme mal an, dass Du die zuständige ..... Nutzerin
kennst und darüber in Kenntnis setzen wirst? Danke.
-----------------------------8<----------------------------