Re: postgres in HA constellation

Hi,

Bruno Wolff III <bruno(at)wolff(dot)to> wrote:
> On Wed, Oct 04, 2006 at 11:23:45 -0000,
> Sebastian Reitenbach <itlistuser(at)rapideye(dot)de> wrote:
> >
> > something I thought that might work:
> > is there sth. that will repair an inconsisten postgresql datastore? e.g.
the
> > master database died, the slave will mount the storage, then repair it in
a
> > reasonable time, and then start to work.
>
> You can just start the slave server and it will recover using th WAL files
> and should do so in a short time. However, you MUST be certain that the
> master is no longer running when the slave starts or your database WILL BE
> TRASHED.
that sounds great, that I can just start the slave, and it will repair
whatever broke. I am aware of that I have to make sure that the master is
really dead.

> >
> > are there any other possibilities that might work that I am not aware of?
> > anybody has experiences with postgres in a HA environment with shared
storage?
>
> You can also use servers with redundant hardware (hotplug CPUs and the like)
> to make failure less likely. If you get the hardware failure rates down to
> that of your storage system, that might be good enough for your purposes.
>
> If you have multiple data centers to protect against disaster, then you
might
> look at SLONY which you can use to replicate to a slave system. However, I
> think it is possible for the master to report a transaction as commited
> before it is shipped off to the slave, so that if the master fails you might
> lose some transactions when switching to the slave. But double check with
> the SLONY documentation on this.

I just have one data center, no remote far away replication is needed.

thank you all for your answers

kind regards
Sebastian