Slony for upgrades

On Mon, 15 Oct 2007, Bruce Momjian wrote:

Seems we didn't have any mention of Slony for upgrades in the migration
section, so I added it:

<para>
It is also possible to use <productname>Slony</> to create a slave
server with the updated version of <productname>PostgreSQL</>. The
slave can be on the same computer or a different computer. Once it
has synced up with the master server (running the older version of
<productname>PostgreSQL</>), you can switch masters and make the slave
the master and shut down the older database instance. Such a
switch-over results in only several minutes of downtime for an upgrade.
</para>

Bruce, do you think we should say several minutes of downtime? It's been my
experience that the downtime is usually measurable in seconds. I don't think
I've ever had a switchover take more than 1 minute.

Excellent catch and good work by the way!

--
Jeff Frost, Owner <jeff@frostconsultingllc.com>
Frost Consulting, LLC http://www.frostconsultingllc.com/
Phone: 650-780-7908 FAX: 650-649-1954

Jeff Frost wrote:

On Mon, 15 Oct 2007, Bruce Momjian wrote:

Seems we didn't have any mention of Slony for upgrades in the migration
section, so I added it:

<para>
It is also possible to use <productname>Slony</> to create a slave
server with the updated version of <productname>PostgreSQL</>. The
slave can be on the same computer or a different computer. Once it
has synced up with the master server (running the older version of
<productname>PostgreSQL</>), you can switch masters and make the slave
the master and shut down the older database instance. Such a
switch-over results in only several minutes of downtime for an upgrade.
</para>

Bruce, do you think we should say several minutes of downtime? It's been my
experience that the downtime is usually measurable in seconds. I don't think
I've ever had a switchover take more than 1 minute.

Excellent catch and good work by the way!

Thanks, changed to seconds. I thought someone told me <5 minutes a
while ago but I might have been mistaken.

--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://postgres.enterprisedb.com

+ If your life is a hard drive, Christ can be your backup. +

On Tuesday 16 October 2007 01:38, Bruce Momjian wrote:

Jeff Frost wrote:

On Mon, 15 Oct 2007, Bruce Momjian wrote:

Seems we didn't have any mention of Slony for upgrades in the migration
section, so I added it:

<para>
It is also possible to use <productname>Slony</> to create a slave
server with the updated version of <productname>PostgreSQL</>. The
slave can be on the same computer or a different computer. Once it
has synced up with the master server (running the older version of
<productname>PostgreSQL</>), you can switch masters and make the
slave the master and shut down the older database instance. Such a
switch-over results in only several minutes of downtime for an upgrade.
</para>

Bruce, do you think we should say several minutes of downtime? It's been
my experience that the downtime is usually measurable in seconds. I
don't think I've ever had a switchover take more than 1 minute.

Excellent catch and good work by the way!

Thanks, changed to seconds. I thought someone told me <5 minutes a
while ago but I might have been mistaken.

I might question the strict reference to Slony here. AIUI you could do the
same thing with Bucardo and a couple of other replication solutions as well.

--
Robert Treat
Build A Brighter LAMP :: Linux Apache {middleware} PostgreSQL

Robert Treat wrote:

On Tuesday 16 October 2007 01:38, Bruce Momjian wrote:

Jeff Frost wrote:

On Mon, 15 Oct 2007, Bruce Momjian wrote:

Seems we didn't have any mention of Slony for upgrades in the migration
section, so I added it:

<para>
It is also possible to use <productname>Slony</> to create a slave
server with the updated version of <productname>PostgreSQL</>. The
slave can be on the same computer or a different computer. Once it
has synced up with the master server (running the older version of
<productname>PostgreSQL</>), you can switch masters and make the
slave the master and shut down the older database instance. Such a
switch-over results in only several minutes of downtime for an upgrade.
</para>

Bruce, do you think we should say several minutes of downtime? It's been
my experience that the downtime is usually measurable in seconds. I
don't think I've ever had a switchover take more than 1 minute.

Excellent catch and good work by the way!

Thanks, changed to seconds. I thought someone told me <5 minutes a
while ago but I might have been mistaken.

I might question the strict reference to Slony here. AIUI you could do the
same thing with Bucardo and a couple of other replication solutions as well.

OK, I now say "like Slony":

It is also possible to use replication like <productname>Slony</> to
create a slave server with the updated version of
<productname>PostgreSQL</>. The slave can be on the same computer or
a different computer. Once it has synced up with the master server
(running the older version of <productname>PostgreSQL</>), you can
switch masters and make the slave the master and shut down the older
database instance. Such a switch-over results in only several seconds
of downtime for an upgrade.

--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://postgres.enterprisedb.com

+ If your life is a hard drive, Christ can be your backup. +