Failover configuration

Wout

Wout

Hi, I am using FreeBSD to host web and mail services. Currently, my setup is as follow:

Server1 in datacenter1: 1 web jail, 1 mail jail
Server2 at datacenter2: 1 web jail, 1 mail jail (failover)

The web jails have Apache, MySQL, Pure-FTPd and Bind installed.
The mail jails have Postfix, Dovecot and OpenLDAP installed.

MySQL and OpenLDAP are replicated. Files (web + mail) are synchronized using rsync.

In case server1 goes down, I modify the DNS entries to server2.

I will be upgrading to FreeBSD 9 soon, and I am thinking about changing my failover setup using HAST/CARP. Doing so I will move server2 to the same location as server1 (datacenter1).

Advantages:
  • Fast switch (+ automatic) to failover server, no need to wait for DNS changes.
  • Failover server has always the latest data (web + mail) files (using HAST instead of rsync), no need to check for possibly not synced files.
  • More simple configuration, no need to setup MySQL and OpenLDAP replication.

Disadvantages:
  • Chance of a corrupted MySQL database or OpenLDAP directory?
  • In case I mess up some configuration on primary server, the failover is messed up too.
  • In case datacenter1 goes down, I cannot do any failover.

Any thoughts why I should or should not do this? Thanks for your input.
 
Do it bro you upgrade to FreeBSD 9.
But before make sure to check if you have problem with db fix it and then upgrade.
 
Do the upgrade but keep the setup the same. As you already figured if datacenter1 goes offline for some reason you're in trouble.

You have a good, working setup. Why change it?
 
Thanks for the reply, by now I upgraded to FreeBSD 9, and sticked to my previous configuration. Working great, though I am always interested in improving it :)
 
Nothing wrong with looking to improve things ;)

But I'm afraid your new setup would add several SPoFs (Single Point of Failure). Something you really don't want to have.
 
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