[Date Prev][Date Next] [Chronological] [Thread] [Top]

Re: Mirror mode difference from N-Way Multi-Master



ÐÐÐÐÑÐÐÐÐÐÐ ÐÐÑÑÐÐ wrote:
Ð ÐÑÐ, 08/02/2013 Ð 11:07 -0800, Quanah Gibson-Mount ÐÐÑÐÑ:
--On Friday, February 08, 2013 8:12 PM +0200 ÐÐÐÐÑÐÐÐÐÐÐ
ÐÐÑÑÐÐ <casper@meteor.dp.ua> wrote:

Ð ÐÑÐ, 08/02/2013 Ð 09:47 -0500, John Madden ÐÐÑÐÑ:
As far as I can see there is no difference in configuration. The only
distinction I can see is the "use case", as N-Way supposed to accept
writes on all Masters, but Mirror only on one at a time.

There are configuration differences (see the Admin Guide for the needed
snippets; N-Way requires MirrorMode and then some) but yes, MirrorMode
requires writes to go to only one node at a time.

I've re-red those sections of docs two more times, still don't see the
difference

There is no configuration difference at this point.  I think there was one
initially ages ago.  The only difference between MMR and mirror-mode MMR is
that in the latter case, writes only go to a single master instead of any
master in the cluster.

In all cases, I strongly advise using delta-syncrepl based MMR with the
most current OpenLDAP release (2.4.33).

Quanah, thanks alot, this clears up things.

Maybe somebody comment on number 4 from my initial post:

4. In Mirror mode, can I use UpdateRef on one mirror to direct writes
to another so proxy/balancer will become not required?

Of course not. Updateref is ignored in mirrormode. As it must be, because otherwise the server would never be able to accept writes at all, which would make it useless for failover.

--
  -- Howard Chu
  CTO, Symas Corp.           http://www.symas.com
  Director, Highland Sun     http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP  http://www.openldap.org/project/