On Seg, 2009-09-28 at 15:55 +0100, Ed W wrote:
You didn't get much answer to this - I'm probably not the best person to answer, but
Are there any performance benefits to using a proxying server, or is it just for splitting mailstores?
I think this is the main reason for the proxying option. It would appear that others have measured the performance load of the proxy task and found it near negligible? Hence it seems possible to use a bunch of backend servers and a few frontend servers to forward the user to the correct backend server. I believe each connection needs to be setup each time though, so for sure some more advanced proxies with persistent caching of connections may offer a performance improvement if your servers are loaded due to the login part (but I guess measure this first before assuming it's so?)
Proxy servers are usually set between the webmail and the imap server.
That's because webmails are a bitch regarding opening+closing connections and so the proxy gets most of connection + auth + do something + disconnect and keeps a limited pool of per user connections to the imap servers that it re-uses. Proxies are usually installed on the same servers that the webmail, with the webmail connecting to 127.0.0.1:someport.
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