On Sat, Jun 16, 2012 at 6:53 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
> On 10 June 2012 19:47, Joshua Berkus <josh@agliodbs.com> wrote:
>
>> So currently we have a major limitation in binary replication, where it is not possible to "remaster" your system
(thatis, designate the most caught-up standby as the new master) based on streaming replication only. This is a major
limitationbecause the requirement to copy physical logs over scp (or similar methods), manage and expire them more than
doublesthe administrative overhead of managing replication. This becomes even more of a problem if you're doing
cascadingreplication.
>
> The "major limitation" was solved by repmgr close to 2 years ago now.
It was solved for limited (but important) cases.
For example, repmgr does (afaik, maybe I missed a major update at some
point?) still require you to have set up ssh with trusted keys between
the servers. There are many usecases where that's not an acceptable
solution. One of the more obvious ones being when you're on Windows.
repmgr hasn't really *solved* it, it has provided a well working workaround...
IIRC repmgs is also GPLv3, which means that some companies just won't
look at it... Not many, but some. And it's a license that's
incompatible with PostgreSQL itself.
> So while you're correct that the patch to fix that assumed that
> archiving worked as well, it has been possible to operate happily
> without it.
>
> http://www.repmgr.org
>
> New versions for 9.2 will be out soon.
That's certainly good, but that doesn't actually solve the problem
either. It updates the good workaround.
--
Magnus Hagander
Me: http://www.hagander.net/
Work: http://www.redpill-linpro.com/