Re: replicate or multi-master for 9.1 or 9.2

On 09/27/12 9:37 PM, Jon Hancock wrote:
> We have a new pg system on 9.1, just launched inside China. We now
> know we may need to run a replicate, with some writes to it outside
> China. Would like some advice. Here are parameters:
>
> 1 - Our data center is in Beijing. If we have a replicate in a data
> center in California, we can expect the bandwidth to vary between the
> Beijing and California servers and for any connection between the two
> servers to break down occasionally. How well does pg replication work
> for suboptimal connects like this?
>

not very well. you might do better with log shipping for an offsite
backup, but then hte offsite standby will be farther behind the master
server

> 2 - Is multi-master an option to allow some writes to the otherwise
> slave California db?
>

not with any built in replication method.

and, any external replication system that allows multimaster inherently
has to have compromises on transactional integrity. what happens when
both masters update the same records while the replication is delayed
due to above network outages?

> 3 - Would trying this on 9.2 be a better place to start? I don't
> think there is any reason we couldn't migrate up at this point.
>

there's nothing in 9.2 that would change the above facts of life.

--
john r pierce N 37, W 122
santa cruz ca mid-left coast