Re: issue about the streaming replication

On Sun, Mar 12, 2017 at 5:24 PM, Jinhua Luo <luajit(dot)io(at)gmail(dot)com> wrote:
> I think this diverge scenario is common, because it's likely the
> master would crash due to some hardware issue (e.g. power off) which
> would cause some committed transaction has not yet synced to slave,
> while the slave would be promoted to new master and accepts new
> transactions, then how to recover the old master? Moreover, how to
> recover the data on old master which is missing on new master?

pg_rewind (https://www.postgresql.org/docs/9.6/static/app-pgrewind.html)
has been designed with exactly this scenario in mind, aka recycling a
past master as a slave to a promoted node. Have you looked at it? What
you are trying to do is much likely going to create corruptions on
your systems, so I am not surprised that you see inconsistency
failures, what you are seeing is pretty much the tip of hte iceberg.
--
Michael