2010/11/16 Daniel Friesen lists@nadir-seen-fire.com:
Ok, then... How many databases are in the cluster being served by nextJobDB? How long does it take to connect to all the databases and figure out what ones have pending jobs?
I don't know how long it takes exactly. I do know that we're caching the list for 5 minutes (this caching was broken between Sep 09 and today, causing the script to regenerate the list each time).
The list is generated by connecting to each cluster and running one large query that covers all the databases in that cluster. We have about 815 databases spread over 6 clusters (three clusters of one, one of three, one of ~20 and one with the other ~790), so we only need to connect to 6 DB servers and run one query on each.
Roan Kattouw (Catrope)