So I see that the message store has been divided into metadata stored in mysql and the filessystem for the actual message. I understand that the decision to use the filesystem allowed for increased performance.
I am wondering how hard it would be to store the message blobs in the MySql rather than in the file system. This would allow for a secondary hot backup server to be synced up by simply using the standard master/slave MySql replication.
This concept has been tested in production for some time now by the developers of DBMail.org, another open IMAP server, but that uses MySQL exclusively for its message store.
Any thoughts? I was thinking of this more as an optional configuration rather than a replacement of the current system.
I am much more concerned with up time than speed so would be willing to take a performance hit to make this change.