Re: Streaming-only Remastering

On Sun, Jun 17, 2012 at 1:11 PM, Josh Berkus <josh@agliodbs.com> wrote:
>
>> 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:

Yeah. Although it seems like it would degenerate to single-remastering
applied a couple times, no?

--
fdr