Web Hosting Talk : Web Hosting Main Forums : VPS Hosting : DRBD and HeartBeat

[elvis1]

Hi guys any clue of where I can find a useful guide and easy Centos guide to configure DRDB and Heartbeat?

Also : is there any advantage of this over Haproxy?

Thanks

[LinologyNetworksLLC]

That's a fun one! I am going to bank of most people not having a clue what's you're talking about. I would head over to the CentOS wiki, they have a tutorial that is pretty solid.
http://wiki.centos.org/HowTos/Ha-Drbd

Depending on what you need to do, you may want to even considering checking out the Cluster Suite. It may be overkill for you but will give you some other options.

Is it better that HAProxy, meeh, I think it's more of being a different approach that being better. It depends on what you want to accomplish. HAProxy is going to give you front-side load balancing for spreading load across multiple servers. DRDB is going to give you HA storage for multiple storage.

The question would be what is your primary objective? Are you deploying HA to prevent a storage outage, or are you deploying multiple servers for availability? If you can give me some more insight on what you want to accomplish, I could give some more guidance.

[elvis1]

Hi Linology!
My aim is to be : "deploying multiple servers for availability". I am also looking forward to have something like geodns to have the shortest route to client.

Ive already been into that guide but yum install heartbeat drbd kmod-drbd retrieved me an error which obliged me to install it without broken modules or something like that.

After doing such I used locate ( previously update) to find drdb.conf and it was non existant.

[LinologyNetworksLLC]

I assume you ran all the updated prior to the packages, I have never had an issue with that setup on top of a clean system.

What type of content do you have? If you're content isn't perpetually changing, you could probably get away with just using rsync between 2 nodes and heartbeat to detect when one goes down. The nature of content. and whether DBs are involved matters here. Remote DBs could help there.

If load isn't an issue you could also go with dual vps/server/nodes running heartbeat on top of shared storage. This is the route I have typically gone with our infrastructure. We run 2 vms on different servers attached to our HA storage cluster. The failover time is however long it takes the node ot boot normally, so you do end up with basically a hard reboot/restart on the device, but its easy to deploy.

I have typically used Debian for HA setups that don't involve a cluster suite stack. CentOS/RHEL are much easier to manage in HA setups using Cluster Suite and it's method, versus going it from scratch.

To be honest, there are alot of ways to deploy this. If you want to go the DRDB+Heartbeat route, and don't have any specific need for CentOS, I find it significantly easier on Debian.

Considering this is a VPS forum, if your host has a shared storage stack, versus the traditional used raid+lvm, you can get real creative. I could think of a half dozen ways to do it with shared storage, be it clustered or drdb.