[vPostMaster] Number of user limitations?

[Sean Reifschneider]

On Tue, Sep 26, 2006 at 08:50:37AM -0700, Mike Seitz wrote:
>contemplating moving my whole email system to VPostmaster and am slightly
>concerned about the number of users that I'm going to be putting on it.
>It'll be to the tune of about 30,000 mail boxes spread over a few servers.

While vPostMaster was designed to be run in a cluster, for handling a lot
of users, I don't know that there has ever been an install on this scale.
I would definitely be willing to work with you on the deployment of that.

The database is designed so that it can be a dedicated machine, and
the client-facing POP/IMAP/SMTP/webmail/web management boxes can hang off
that database machine.  Typically, you'd also run the
/var/spool/vpostmaster and also maybe /usr/lib/vpostmaster off an NFS
server, so that all machines have access to the same file-share.  Then you
could run as many front-end machines as the NFS and database servers can
handle.

Of course, for smaller deployments you could have the NFS and database
server be the same machine.

The number of machines depends on the typical features you are using as
well.  SpamAssassin and ClamAV tend to hit the frontend system pretty hard.
Greylisting hits the database harder than the system.

There are some optimizations I've considered adding to allow vPostMaster to
scale further by using a query cache to reduce the number of database hits,
but none of that has been implemented yet.  So, currently, every mail
delivery involves several database hits.

Sean
-- 
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Sean Reifschneider, Member of Technical Staff <jafo at tummy.com>
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