Re: primary/backup and ability to start a service?

[Paul Baker <pbaker@xxxxxxxxxxxxxxx>]

Ricardo Kleemann wrote:
> Hi guys,
>
> Does LVS support a primary/backup type of scenario? Aside from load
> balancing, I would like to be able to have a setup where I can have a
> primary database server and one or more hot backup servers.
>
> So if the primary goes down, LVS then not only redirects to the backup,
> but also starts up the database service as part of "bringing it up".
>
> The main reason is because it's very difficult to get useful replication
> out of something like mysql, so instead I thought of having a primary with
> one or more hot backups, and the data shared over NFS. The hot backups
> typically would not even be running the daemon, that way there's no
> problems with the shared data. But if the primary goes down, then the
> backup can take over, starting up the daemon.
>
> Anyways, can LVS be setup to do that rather than load-balancing? And also,
> can it run a script when it brings up the secondary?
You would be MUCH better off using heartbeat provided at 
http://www.linux-ha.org/. It provides all of those things you requested. 
And you won't even need to use a modified kernel or extra machines 
besides your primary and backup database servers.
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Paul J. Baker                                Internet Systems Developer
pbaker@xxxxxxxxxxxxxxx                                  Where2GetIt.com
phone 847-498-0111x234
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