Feb 06, 2009 16:23
Its absolutely unbelievable the difference an IMAP server with server side caching makes when the majority of its requests come from webmail with 0 client side caching.
Ancient ass Courier is gone, new and shiny dovecot is uber.
We went from average request times in the 60-80 second range during moderate load to peak load time requests averaging 3-5 seconds.
Yeah, I'm a fucking hero cuz I told 'em to do this a year ago when the problems were barely beginning to manifest and it got shelved cuz "the imap servers are stable, we need to devote resources to these other projects that'll generate revenue." Except they never generated revenue, and as predicted the IMAP servers weren't really stable we just didn't have the data to prove it.
Finally december roles around and the issue blows up with customers and we instrument the web code and low and behold IMAP performance is terrible and then some, so I dust off the conversion project. Couple days testing to make sure nothing blows up, no duplicate message downloads etc, implement yesterday morning and today I could reduce the cluster by 60% and STILL see a 50x performance improvement.