Thread: Resync postgres database after master slave replication

Resync postgres database after master slave replication

From
shailesh
Date:
Hello,

I have setup postgres 8.4 master-slave replication. What we want to do is

at some point, make both master slave independent and allow writes to both
for a day, and then somehow sync them again to continue master-slave. Is
this possible?
What I understood about master-slave is that the both databases must be in
sync only then master-slave can  work. That's why I am thinking I have to
somehow merge both databases.
What manual (or automated) steps can be taken to get both databases merged
so that master-slave can resume? Will there be any wrt application (liferay
6)?

Appreciate any help.

S



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Re: Resync postgres database after master slave replication

From
Jan Lentfer
Date:

> Am 21.05.2015 um 15:18 schrieb shailesh <ligade_shailesh@bah.com>:
>
> Hello,
>
> I have setup postgres 8.4 master-slave replication. What we want to do is
>
> at some point, make both master slave independent and allow writes to both
> for a day, and then somehow sync them again to continue master-slave. Is
> this possible?
> What I understood about master-slave is that the both databases must be in
> sync only then master-slave can  work. That's why I am thinking I have to
> somehow merge both databases.
> What manual (or automated) steps can be taken to get both databases merged
> so that master-slave can resume? Will there be any wrt application (liferay
> 6)?
>
> Appreciate any help.
>

That is not possible and I can't think of any system that will (reliably) do that. It's actually something most people
willwant to avoid by all possible means - split-brain on purpose. 

Jan