Re: HA options

On Tuesday, January 17, 2012 10:34:54 AM Tim Uckun wrote:
> Hey Guys.
>
> It's been a while since I looked into this and it seems like new
> options have cropped up for postgres HA and scalability. Is there a
> consensus on the "best" way to achieve HA. My primary concern is HA
> but of course any scalability gains would be more than welcome. All
> the servers will be virtual on either rackspace or amazon so that's
> possibly a complication.
>
> http://www.drbd.org/ ??
> Built in hot standby and hand rolled scripts.

I have a few clusters running on EC2 using DRBD to replicate between
availability zones. It's not fast, but it works. If your write load is under
30MB/sec it's definitely an option. I run DRBD over SSH tunnels to get around
the random IP address issue. I use heartbeat on top for resource
management (I know it's not ideal with the single communications
path, but what can you do), and DDNS with really short TTLs for the cluster
names.

I've also had success using the native replication to spin read-only slaves off
those HA masters, using pgpool to load balance selects.