On 15/11/2011 21:49, Albert Shih wrote: > Le 12/11/2011 à 00:35:26+0000, Ed W a écrit > >> Quick question: What does perdition buy you versus not having it? > At this moment nothing (that's why it's not a urgent problem), but in > sometime the purpose of perdition is to «virtualizing» the storage of the > mail. > > Suppose you have to build a mail system for 5000 users with 2 Go for each > persons, but you knwon in one-two year it's 10 Go. You can buy a huge servers > now for 50-60To but it's very expensive (lot more than two years) or you > can buy a smaller server today 10To. But what you going to do in 1 year ? Are > you going to just put in trash your 10To ? I'm not. > > With perdition (or any imap proxy) you can create a map (according what you > want) to redirect the imap connection to the right server. > > For example : > > if the name match ^[a-i]* go to old server > if the name match ^[j-z]* go to second new server. > etc... >
Just a note, but if you have dovecot then you can do all this within dovecot itself. Check out the "Proxy" feature and note that it can be persuaded to proxy connections to any other machine. The proxy to use can be read from the same database as your user/auth - so for example you can create some kind of user database with username/password/backend_server and have dynamic control over where users end up Some folks have suggested that the proxying is of very low cpu/resources, and some have suggested that you can avoid even having dedicated frontend/backend proxy servers and just have all frontend servers which proxy to the correct other frontend if the initial connection was a miss. ie setup three frontend servers, you have a 1:3 chance of accidently hitting the correct one or proxy to the correct on if you miss. More powerful variations obviously also work, but for some installs the simple may be an advantage I do hear that some think there is a performance advantage in using an imap proxy, hence curious if anyone measures this or not? Timo (author of dovecot) believes that there should be little advantage if both on the same machine, but I'm unsure if net latency is a practical problem if they are on separate machines and hence an imap proxy might save you several RTT trips for each page view? Cheers Ed W -- [email protected] https://inverse.ca/sogo/lists
