Load Balancing / Mailbox routing

[mlcnm]

According to several wiki documents, real load balancing (multiple servers can manage the same mailbox with a central datapool) is not possible with Zimbra, since transactions are very IO bound and thus the mailboxes are tied to a certain Zimbra server.

In our existing setup we use nginx, which performs the login for IMAP and POP3, connects to the according backend of the mailbox and is just proxying the further requests and responses during IMAP and POP3 sessions. So far, we could retain this for Zimbra.

But with Zimbra, there is also the AJAX frontend, and I have no idea how to load balance it. To balance the load, the frontend would have to know to which backend to connect. It cannot know this before the login is done. But the login screen is provided by the Zimbra server.

So how can I setup up a central zimbra frontend URL like https://zimbra.my-isp.com which hides the real backends (like zmserver1, zimserver2 etc.) from the customer? This isn't only interesting for the AJAX frontend, but also for WebDav.

[Artturi]

Well, maybe you could build something based on a single sign on system.
You'd already know who is accessing some special page, and redirect from that.

Regards,

[mlcnm]

But even providing a single sign on page and redirecting to a URL like server2313.myp-isp.com looks unprofessional. I cannot image that I'm the first one asking for that. I thought there are big installations of Zimbra? What solution does Zimbra provide for this (not very special) case?

[Klug]

Originally Posted by mlcnm

In our existing setup we use nginx, which performs the login for IMAP and POP3, connects to the according backend of the mailbox and is just proxying the further requests and responses during IMAP and POP3 sessions. So far, we could retain this for Zimbra.

There's a Zimbra-proxy module designed for that.

And guess what ?
zimbra-proxy is actually nginx 8)

Originally Posted by mlcnm

So how can I setup up a central zimbra frontend URL like https://zimbra.my-isp.com which hides the real backends (like zmserver1, zimserver2 etc.) from the customer? This isn't only interesting for the AJAX frontend, but also for WebDav.

Have a look at the multi-servers installation documentation and do some search on zimbra-proxy on the forum.

What you want is exactly what zimbra-proxy was designed for : it balances (not load balances) the trafic to the good server depending on the user/password. And it works for the AJAX webUI, HTML webUI, pop3, imap4, Zimbra Mobile, etc.

And you can loadbalance/failover a pair of zimbra-proxy servers if needed.