Let me clarify - I don't know how/where the thought is that I need
something per se, I personally like deploying the scaled solutions and
playing with software that others have written. Can I deploy the right
hardware and configurations to meet pretty much near anything anyone could
ever need? I say yes, I can. BUT it would so much cooler IF, there was a
multi-master environment configured for the sake of doing it.
I'm glad that not everyone has this disposition about 'why do we need it.'
The pursuit of knowledge is the facilitator of innovation.
As I mentioned, in initial post, I've got OpenLDAP integrated with
postgresql & another application, which my friends and I are going to
release soon as a service - we'll see how far that goes. Nonetheless, I
would like to have a multi-master postrgresql cluster handling my backend
content.
Why? Because I'd like to. If you're happy with not using pursuing it,
great, that works for you. Sweet! Killer! Rock on! My take away is, now
besides knowing their's no active pursuit on the matter, perhaps others in
this huge forum, now know more status, thanks to those of 'you' who are so
up to date! In all sincerity, thank you for clarifying that status.
There are still advanced users our here, who would still like to see an
opensource product reach that level stature, such that those who don't
know - i.e. 'most' managers and people who have decision making power -
would not be deterred from using Postgresql because it doesn't have a
quote unquote, 'multi-mater' replication.
On Fri, 1 Jun 2007, Andrew Sullivan wrote:
As an aside -- please don't start new topics in old threads.
On Fri, Jun 01, 2007 at 10:42:02AM -0400, gonzales@xxxxxxxxxxxxxx wrote:
I'm disappointed because SLONY-II has not been released yet to support
multi-master replication!
Well, I wouldn't hold my breath. Most of the participants in that
project moved on, after concluding either that it wasn't going to
solve their problems, or concluding that it'd cost too much to
develop and support for the likely benefit it would deliver. As near
as I can tell, development on the project stopped.
The inspiration for the Slony-II project, Postgres-R, has been ported
forward to 8.x series by Markus Schiltknecht. Last I heard, he was
looking for people to underwrite his work on that project. So if you
really want those features, the obvious way to do it is to put a
programmer on it, and there happens to be a programmer who has a demo
as his argument that it can be done, and he can do it.
I think you have to understand, however, that Slony-II or Postgres-R
was not in fact the magic carpet you seem to think it was to be.
There are some pretty significant limitations to the async
multimaster approach it uses. To begin with, AFAIK nobody has a
working, production-grade group communication system available for
use by Postgres -- the ones that the prototypes were built on were
pretty hacky, and appeared not to be ready for prime time. Second,
nobody has come up with any way to make this work with READ COMMITTED
mode, which means you pay a really huge price for the replication.
My real question in all this is, "What is the problem you are trying
to solve?" Hot failover using combinations of hardware and software,
and a disk array that can be mounted across two machines, is actually
probably good enough for most cases, assuming it is implemented
correctly (see recent discussion on this topic). So the availability
piece is mostly solved. What else do you want?
A
--
Louis Gonzales
louis.gonzales@xxxxxxxxxxxxxx
http://www.linuxlouis.net
