Postgres-R released as free software

[Posted July 15, 2008 by corbet]

Postgres-R is a multi-master database replication mechanism aimed at high-availability, clustered environments. Postgres-R developer Markus Wanner has just announced that it is now free software. As a free software project Postgres-R is in an early state, being distributed as a patch to PostgreSQL proper. But there seems to be some interest in this release, which should help it to be pulled into shape quickly. See this additional posting for some information on the current status of this code.

Postgres-R released as free software

Posted Jul 15, 2008 20:43 UTC (Tue) by DG (subscriber, #16978) [Link] (4 responses)

I'd not heard of this project before - but it would be really great if PostgreSQL had an
'official' integrated replication setup like MySQLs.... 

Has anyone used this, or other PostgreSQL replication 'things'? Comparisons with MySQL
welcome....

Standard PostgreSQL replication

Posted Jul 15, 2008 20:46 UTC (Tue) by corbet (editor, #1) [Link] (1 responses)

FWIW, the postgresql developers have recently committed themselves to providing a standard, easy-to-setup replication mechanism. Last I heard, there was no real decision on which it would be; I don't think Postgres-R has been considered for that role so far. Stay tuned - but be prepared to wait for a little while yet.

Standard PostgreSQL replication

Posted Jul 15, 2008 21:47 UTC (Tue) by dlang (guest, #313) [Link]

actually there was a lot of discussion.

what they are planning to implement is syncronous single-master replication implemented via
the WAL logs

Postgres-R released as free software

Posted Jul 15, 2008 21:30 UTC (Tue) by flewellyn (subscriber, #5047) [Link] (1 responses)

I think part of the problem with providing a 'standard' replication solution in PostgreSQL is
that there are so many different ways to do it, and which one you use will depend on your
setup.  Slony-I, for instance, is a "single-master, multiple-slave" solution, while pgpool
offers "peer-to-peer" replication with or without load-balancing, and apparently PostgreSQL-R
offers "multi-master" replication.

Which one should you use?  There is no one-size-fits-all solution.  The nice thing is,
PostgreSQL is so easily extendable (while running, I might add), that it can offer all of the
above, with the administrator choosing which one is appropriate for the installation's needs.

Postgres-R released as free software

Posted Jul 22, 2008 7:07 UTC (Tue) by markusw (guest, #53024) [Link]

Well, being Single-Master is only an implementation limitation, not one the user ever wants by
herself. And even if she does: Postgres-R can be used as a single-master replication system,
by just sending all updates to one node.

Postgres-R released as free software

Posted Jul 16, 2008 12:20 UTC (Wed) by ringerc (subscriber, #3071) [Link] (1 responses)

See the following URL for a recent statement from the core team that shows a new focus on replication in PostgreSQL.

http://archives.postgresql.org/pgsql-hackers/2008-05/msg00913.php

It looks like synchronous warm standby will be first, followed by read-only query support to the hot standby server(s). The existing replication options (async warm standby and row-level replication) are already very handy, though.

This adds another option into the mix. I haven't seen any examination of it on the Pg lists yet, which is odd.

Postgres-R released as free software

Posted Jul 22, 2008 7:09 UTC (Tue) by markusw (guest, #53024) [Link]

> This adds another option into the mix. I haven't seen any examination of
> it on the Pg lists yet, which is odd.

I guess it's just summer vacation time... According to statistics, there were over 200
downloads of the patch.