Re: Streaming-only Remastering

> Instead of using re-synchronization (e.g. repmgr in its relation to
> rsync), I intend to proxy and also inspect the streaming replication
> traffic and then quiesce all standbys and figure out what node is
> farthest ahead.  Once I figure out the node that is farthest ahead, if
> it is not a node that is eligible for promotion to the master, I need
> to exchange its changes to nodes that are eligible for promotion[0],
> and then promote one of those, repointing all other standbys to that
> node. This must all take place nominally within a second or thirty.
> Conceptually it is simple, but mechanically it's somewhat intense,
> especially in relation to the inconvenience of doing this incorrectly.

So you're suggesting that it would be great to be able to
double-remaster?  i.e. given OM = Original Master, 1S = standby furthest
ahead, NM = desired new master, to do:

1S <--- OM ---> NM

OM dies, then:

1S -----------> NM

until NM is caught up, then

1S <----------- NM

Yes?

-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com