RE: Installing A Web, Email And MySQL Database Cluster

[cjhmdm]

Hello, I've just completed my cluster set up following this guide

Everything seems to be on the up and up and working properly, and now my question is... can I extend this to work across 3 servers? If so, would it just be a matter of setting up the 3rd as a slave to the slave, or a 2nd slave to the master?

Thanks for any insight :-)

[falko]

Add it as a 2nd slave to the master.

[cjhmdm]

Hi, thanks for the info.

Also.. on this specific set up, what software actually handles the load balancing? I didn't see any of the usual (haproxy/ultramonkey) softwares installed so is it safe to assume that a. load balancing is handled through ispconfig or b.this set up is for High Availability and not load balancing?

Thans again and have a good day.

[falko]

This is from the ISPConfig 3 Manual:

The third scenario is to have slave servers or mirrors of the ISPConfig 3 server. In this case you cannot create any items on the mirror (this server cannot be selected when you create a new item in ISPConfig 3), but instead the configuration (web site configuration, email configuration, etc.) will be copied from the master to the mirror (just the configuration, not any web site contents, etc. - if you want this, you can achieve this by using rsync or using a cluster filesystem like GlusterFS or some kind of network-attached storage, and you'd have to use one of these techniques on the directories /var/www for the web sites' contents and /var/vmail for the emails - for MySQL databases, you'd have to use MySQL master-master replication). If you select a master server in the Is mirror of Server field (see chapter 4.9.2.1), the server for which you select the master will act as a mirror, not as a full-fledged server. If you have a failover-IP address that you can switch between the master and the mirror (e.g. automatically with heartbeat/keepalived/etc. or manually, e.g. from your hoster's control panel), you can achieve high-availability because if the master fails, the mirror can take over (mirror setup). Of course, this can be mixed with a multiserver setup (i.e., you can have a cluster with full-fledged servers like in the second scenario and with mirrors).