Re: Dbmail Hybrid
Josh Marshall <josh <at> worldhosting.org>
2009-05-04 23:07:25 GMT
I believe we've all gone over this before, but remember if you do
something like this, you lose or complicate redundancy.
For example, our dbmail installation, which has over 4500 mailboxes and
100,000 emails/week has three mail servers and two database servers. The
database servers are MySQL in a master-master replication setup, with
one set as the active using ucarp (it's not smart to load balance
database servers with dbmail). The three mail servers are load balanced
with LVS on the firewalls. We have a backup database server that
replicates off a particular master, which is stopped daily to take a
snapshot, then restarted again. This takes backup load off the primary
If you store the messages outside the database and wanted redundancy
then you would have to share them on a file server using something like
NFS. This would add complexity, and I believe it would not increase
speed or availability.
A few other questions to ask yourself before doing such a thing include:
* Will it change the amount of disk space required? (Not really)
* What is your backup strategy? You may have to shut down the server to
get a true snapshot.
* What is your recovery strategy? Can you do a point-in-time recovery?
(NO, files are created and deleted)
Everything I see is that to pull the message contents out of the
database and store in the filesystem:
* Adds complexity to the creation and deletion of emails