On Wednesday 20 February 2008 21:00:42 Thomas Ledbetter wrote: > So.. Ive been reading up hardcore on Berkeley database administration > regarding how to do archival and recovery, and its pretty cool stuff. > > Yet I have the following questions: > > Database archival will be done on one of our master servers, so its > not necessary to keep alot of old transaction logfiles on the replicas, > but in order to clean out them out, a periodic checkpoint is necessary. > > Initially, I was thinking that we should do this once per day, off > hours,
How would you ensure that the checkpoint occurs in off-hours ? > but would it make more sense to do this more frequently over the > course of the day to keep the checkpoint process less expensive per > iteration? IMHO, yes. > What kinds of metrics should be used to determine how frequently this > should be done? This would depend on the frequency of changes, and how long you can afford to have database recovery run for. I usually go with something around 5-10 minutes. > Second, would there be that great of a performance gain when disabling > transaction logging altogether? Yes, but if you ever have an unclean shutdown, you may have to reload/resync from scratch. But, how much performance do you need, and how much are you getting now? > If I have two master servers keeping, say, a week's worth of > transaction logs, a sound archival process, and a backup LDIF, would it > make sense to just disable transaction logging altogether across the > replicas? If you can afford taking a slave down for a re-import or re-sync, maybe. However, I would sacrifice a bit of performance to avoid this myself. > Third, I now understand how to do archival and recovery using the > Berkeley tools, but is there a 'best practice' document out there > anywhere from someone who utilizes this method that I could take a look > at to make sure Im not missing anything? Well, I wrote these a long time ago, and while they worked fine when testing them for what I needed, I haven't needed them for anything (besides removing the old transaction logs): http://svn.mandriva.com/cgi-bin/viewvc.cgi/packages/cooker/openldap/current/SOURCES/ldap-common?view=log http://svn.mandriva.com/cgi-bin/viewvc.cgi/packages/cooker/openldap/current/SOURCES/ldap-hot-db-backup?view=log Regards, Buchan
