Re: Configuring synchronous replication

On 21/09/10 11:52, Thom Brown wrote:
> My fear would be standby.conf would be edited by users who don't
> really know XML and then we'd have 3 different styles of config to
> tell the user to edit.

I'm not a big fan of XML either. That said, the format could use some
hierarchy. If we add many more per-server options, one server per line
will quickly become unreadable.

Perhaps something like the ini-file syntax Robert Haas just made up
elsewhere in this thread:

-------
globaloption1 = value

[servername1]
synchronization_level = async
option1 = value

[servername2]
synchronization_level = replay
option2 = value1
-------

I'm not sure I like the ini-file style much, but the two-level structure
it provides seems like a perfect match.

Then again, maybe we should go with something like json or yaml that
would allow deeper hierarchies for the sake of future expandability. Oh,
and there Dimitri's idea of "service levels" for per-transaction control
(http://archives.postgresql.org/message-id/m2sk1868hb.fsf@hi-media.com):

> sync_rep_services = {critical: recv=2, fsync=2, replay=1;
> important: fsync=3;
> reporting: recv=2, apply=1}

We'll need to accommodate something like that too.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com