postgresql and replication

Hi, we really want to get a reliable PostgreSQL replication
setup going, with a Master Write server and many Slave Read-Only
servers replicating off the master. This is to allow us to
scale up our low-write/high-read application over many customers.

We've done some research (ie, web searching) and we are not
convinced that PostgreSQL replication projects are production
ready (with one commercial exception). Hopefully we are wrong
however, as the MySQL built-in replication does seem very mature
and makes me look across with envy. But considering all the effort
we've put into our PG installation, we'd rather stick to PG if
possible.

I will briefly list the PG Replication projects I have come across
below. I am looking for more experienced people, who have hopefully
already implemented any of these, or the authors themselves, to
provide more details and guide us in the right direction as to
which project is the "best" to go with. I am happy to summarize
the info we put together for others looking to do the same.

eRServer
http://www.erserver.com/
Commercial, looks professional. Not free.
However, No trial or evaluation ?

PGReplication
http://gborg.postgresql.org/project/pgreplication/projdisplay.php
Software is: Postgres-R with Spread. Free.
Looks to be still very much in development, can only consider beta ?

RServ
http://gborg.postgresql.org/project/rservimp/projdisplay.php
Looks far too beta....
Free

PostgreSQL Replicator
http://pgreplicator.sourceforge.net/
“Store and forward” asynchronous data replication.
Free
Tested up to PG 7.1
Peer-to-peer (single master/slave pair) not multi-slave.

Usogres
http://usogres.good-day.net/
Very simple and not real-time replication. Free.
Just duplication and only one master/slave pair.

Regards,
Chris.

--
Chris Miles
http://chrismiles.info/

On Tue, Aug 26, 2003 at 06:19:12PM +0100, Chris Miles wrote:
> eRServer
> http://www.erserver.com/
> Commercial, looks professional. Not free.
> However, No trial or evaluation ?

There's (about to be?) a free version available now. If you start
grovelling around on gborg some time late this afternoon (uh, EDT), I
think you'll stumble on it.

A

--
----
Andrew Sullivan 204-4141 Yonge Street
Liberty RMS Toronto, Ontario Canada
<andrew(at)libertyrms(dot)info> M2P 2A8
+1 416 646 3304 x110

* Andrew Sullivan (andrew(at)libertyrms(dot)info) wrote:
> On Tue, Aug 26, 2003 at 06:19:12PM +0100, Chris Miles wrote:
> > eRServer
> > http://www.erserver.com/
> > Commercial, looks professional. Not free.
> > However, No trial or evaluation ?
>
> There's (about to be?) a free version available now. If you start
> grovelling around on gborg some time late this afternoon (uh, EDT), I
> think you'll stumble on it.

It appears to be up there now and you can puruse it using ViewCVS. The
LICENSE file in erserver/docs certainly doesn't look like BSD (which is
claimed on the main page) to me though.

Stephen

Hi,

This is a good status.
But i think you have forgotten DBMirror which is in the contrib directory.
I have tried to run it on the same machine but on to 2 differents Postgres
instances. The master on Port 5432 and the Slave on Port 5434. These does
not work as the Perl script in charge of synchronized the Master DB and the
Slave DB, work only on the default port 5432.

I'm waiting for an other machine to create the Slave DB on a different
machine.

Thierry Missimilly

Chris Miles wrote:

> Hi, we really want to get a reliable PostgreSQL replication
> setup going, with a Master Write server and many Slave Read-Only
> servers replicating off the master. This is to allow us to
> scale up our low-write/high-read application over many customers.
>
> We've done some research (ie, web searching) and we are not
> convinced that PostgreSQL replication projects are production
> ready (with one commercial exception). Hopefully we are wrong
> however, as the MySQL built-in replication does seem very mature
> and makes me look across with envy. But considering all the effort
> we've put into our PG installation, we'd rather stick to PG if
> possible.
>
> I will briefly list the PG Replication projects I have come across
> below. I am looking for more experienced people, who have hopefully
> already implemented any of these, or the authors themselves, to
> provide more details and guide us in the right direction as to
> which project is the "best" to go with. I am happy to summarize
> the info we put together for others looking to do the same.
>
> eRServer
> http://www.erserver.com/
> Commercial, looks professional. Not free.
> However, No trial or evaluation ?
>
> PGReplication
> http://gborg.postgresql.org/project/pgreplication/projdisplay.php
> Software is: Postgres-R with Spread. Free.
> Looks to be still very much in development, can only consider beta ?
>
> RServ
> http://gborg.postgresql.org/project/rservimp/projdisplay.php
> Looks far too beta....
> Free
>
> PostgreSQL Replicator
> http://pgreplicator.sourceforge.net/
> “Store and forward” asynchronous data replication.
> Free
> Tested up to PG 7.1
> Peer-to-peer (single master/slave pair) not multi-slave.
>
> Usogres
> http://usogres.good-day.net/
> Very simple and not real-time replication. Free.
> Just duplication and only one master/slave pair.
>
> Regards,
> Chris.
>
> --
> Chris Miles
> http://chrismiles.info/
>
> ---------------------------(end of broadcast)---------------------------
> TIP 2: you can get off all lists at once with the unregister command
> (send "unregister YourEmailAddressHere" to majordomo(at)postgresql(dot)org)

Indeed, a free release of eRServer was released last night and is
available at
http://gborg.postgresql.org/project/erserver/download/download.php
There was an announcement sent to pgsql-announce also.

We will now be evaluating this to see if it is suitable for our
needs.

I spoke to PostgreSQL Inc last night and was informed that they will
be releasing their previous versions of eRServer to the open source
community 6-12 months after it has been replaced by the next
commercial version. The commercial version is still sold, supported
and developed, and is currently at version 1.3. The open source
version just released is a modified version of 1.2 basically.

Cheers,
Chris.

Andrew Sullivan wrote:
> On Tue, Aug 26, 2003 at 06:19:12PM +0100, Chris Miles wrote:
>>eRServer
>> http://www.erserver.com/
>> Commercial, looks professional. Not free.
>> However, No trial or evaluation ?
>
> There's (about to be?) a free version available now. If you start
> grovelling around on gborg some time late this afternoon (uh, EDT), I
> think you'll stumble on it.

--
Chris Miles
http://chrismiles.info/

On Tue, Aug 26, 2003 at 06:05:45PM -0400, Stephen Frost wrote:
> It appears to be up there now and you can puruse it using ViewCVS. The
> LICENSE file in erserver/docs certainly doesn't look like BSD (which is
> claimed on the main page) to me though.

Oops, looks like something didn't get changed. We can fix that.

A

--
----
Andrew Sullivan 204-4141 Yonge Street
Liberty RMS Toronto, Ontario Canada
<andrew(at)libertyrms(dot)info> M2P 2A8
+1 416 646 3304 x110

Look at User Mode Linux:

http://user-mode-linux.sourceforge.net/

It'll let you run multiple linux instances on the same box.

On Wed, 27 Aug 2003, Thierry Missimilly wrote:

> Hi,
>
> This is a good status.
> But i think you have forgotten DBMirror which is in the contrib directory.
> I have tried to run it on the same machine but on to 2 differents Postgres
> instances. The master on Port 5432 and the Slave on Port 5434. These does
> not work as the Perl script in charge of synchronized the Master DB and the
> Slave DB, work only on the default port 5432.
>
> I'm waiting for an other machine to create the Slave DB on a different
> machine.
>
> Thierry Missimilly
>
>
> Chris Miles wrote:
>
> > Hi, we really want to get a reliable PostgreSQL replication
> > setup going, with a Master Write server and many Slave Read-Only
> > servers replicating off the master. This is to allow us to
> > scale up our low-write/high-read application over many customers.
> >
> > We've done some research (ie, web searching) and we are not
> > convinced that PostgreSQL replication projects are production
> > ready (with one commercial exception). Hopefully we are wrong
> > however, as the MySQL built-in replication does seem very mature
> > and makes me look across with envy. But considering all the effort
> > we've put into our PG installation, we'd rather stick to PG if
> > possible.
> >
> > I will briefly list the PG Replication projects I have come across
> > below. I am looking for more experienced people, who have hopefully
> > already implemented any of these, or the authors themselves, to
> > provide more details and guide us in the right direction as to
> > which project is the "best" to go with. I am happy to summarize
> > the info we put together for others looking to do the same.
> >
> > eRServer
> > http://www.erserver.com/
> > Commercial, looks professional. Not free.
> > However, No trial or evaluation ?
> >
> > PGReplication
> > http://gborg.postgresql.org/project/pgreplication/projdisplay.php
> > Software is: Postgres-R with Spread. Free.
> > Looks to be still very much in development, can only consider beta ?
> >
> > RServ
> > http://gborg.postgresql.org/project/rservimp/projdisplay.php
> > Looks far too beta....
> > Free
> >
> > PostgreSQL Replicator
> > http://pgreplicator.sourceforge.net/
> > “Store and forward” asynchronous data replication.
> > Free
> > Tested up to PG 7.1
> > Peer-to-peer (single master/slave pair) not multi-slave.
> >
> > Usogres
> > http://usogres.good-day.net/
> > Very simple and not real-time replication. Free.
> > Just duplication and only one master/slave pair.
> >
> > Regards,
> > Chris.
> >
> > --
> > Chris Miles
> > http://chrismiles.info/
> >
> > ---------------------------(end of broadcast)---------------------------
> > TIP 2: you can get off all lists at once with the unregister command
> > (send "unregister YourEmailAddressHere" to majordomo(at)postgresql(dot)org)
>

On Wed, 27 Aug 2003, Andrew Sullivan wrote:

> On Tue, Aug 26, 2003 at 06:05:45PM -0400, Stephen Frost wrote:
> > It appears to be up there now and you can puruse it using ViewCVS. The
> > LICENSE file in erserver/docs certainly doesn't look like BSD (which is
> > claimed on the main page) to me though.
>
> Oops, looks like something didn't get changed. We can fix that.

Yup, error in commit ... will get that one fixed up in the morning, it
*is* being released under BSDL ... sorry for teh confusion folks ...