Thread: WAL file compatibility
I have a PostgreSQL production server running on CentOS (compiled from source), and I'm planning to setup a hot standby database on another server, running on Ubuntu (default Ubuntu binaries). The production server is running on 8.3.5, and the planned Ubuntu hot standby is running on 8.3.x. Can I use the production WAL files on the Ubuntu standby without problems? Thanks in advance. Radamanthus E. Batnag Senior Technology Architect Devex (The Development Executive Group) Do Good. Do It Well. ™
Radamanthus Batnag <rad.batnag@devex.com> writes:
> I have a PostgreSQL production server running on CentOS (compiled from
> source), and I'm planning to setup a hot standby database on another
> server, running on Ubuntu (default Ubuntu binaries).
> The production server is running on 8.3.5, and the planned Ubuntu hot
> standby is running on 8.3.x. Can I use the production WAL files on the
> Ubuntu standby without problems?
The source and destination servers have to be the same major PG release,
same architecture (no 32-bit vs 64-bit for instance), and built with the
same configure options. OS per se shouldn't matter, but you could
easily get burnt on configure options if you use binaries obtained from
different packagers. Compare pg_config output or check the fields
listed by pg_controldata.
regards, tom lane
On Tue, Oct 20, 2009 at 9:25 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote: > OS per se shouldn't matter > unless you try to do it between windows and some flavor of linux -- Atentamente, Jaime Casanova Soporte y capacitación de PostgreSQL Asesoría y desarrollo de sistemas Guayaquil - Ecuador Cel. +59387171157
Jaime Casanova <jcasanov@systemguards.com.ec> writes:
> On Tue, Oct 20, 2009 at 9:25 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> OS per se shouldn't matter
> unless you try to do it between windows and some flavor of linux
hmmm ... even there, the only risk factor I see would be incompatible
locale behaviors, which you could avoid by making sure to use C locale
on both sides. That could possibly be an issue between any two OSes,
I suppose.
regards, tom lane
On Tue, Oct 20, 2009 at 10:56 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote: > Jaime Casanova <jcasanov@systemguards.com.ec> writes: >> On Tue, Oct 20, 2009 at 9:25 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote: >>> OS per se shouldn't matter > >> unless you try to do it between windows and some flavor of linux > > hmmm ... even there, the only risk factor I see would be incompatible > locale behaviors, which you could avoid by making sure to use C locale > on both sides. That could possibly be an issue between any two OSes, > I suppose. > mmm... i was convinced windows had diferences in binary files just like on text files (ie: in text files there are differences because of the EOL character) but a litlle test seems to confirm that a WAL file generated on windows could be read on linux. -- Atentamente, Jaime Casanova Soporte y capacitación de PostgreSQL Asesoría y desarrollo de sistemas Guayaquil - Ecuador Cel. +59387171157
Tom Lane wrote: > ... > The source and destination servers have to be the same major PG release, > same architecture (no 32-bit vs 64-bit for instance), and built with the > same configure options. OS per se shouldn't matter, but you could > easily get burnt on configure options if you use binaries obtained from > different packagers. Compare pg_config output or check the fields > listed by pg_controldata. > > regards, tom lane > > Out of curiosity, will Pg automatically detect incompatible WAL files and refuse to operate on them throwing the appropriate error or can it appear to work for a while until it suddenly doesn't? Cheers, Steve
Steve Crawford <scrawford@pinpointresearch.com> writes:
> Tom Lane wrote:
>> The source and destination servers have to be the same major PG release,
>> same architecture (no 32-bit vs 64-bit for instance), and built with the
>> same configure options. OS per se shouldn't matter, but you could
>> easily get burnt on configure options if you use binaries obtained from
>> different packagers. Compare pg_config output or check the fields
>> listed by pg_controldata.
> Out of curiosity, will Pg automatically detect incompatible WAL files
> and refuse to operate on them throwing the appropriate error or can it
> appear to work for a while until it suddenly doesn't?
There are checks on the contents of pg_control, not directly on WAL
files, but the system identifier checks should link the two together.
I suspect the largest practical risk is that different OSes might assign
different behaviors to the same locale name. There's really no good way
for Postgres to detect that :-(
regards, tom lane
On Mon, Oct 26, 2009 at 9:03 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote: > > I suspect the largest practical risk is that different OSes might assign > different behaviors to the same locale name. There's really no good way > for Postgres to detect that :-( > Alvaro just remembers me that tablespaces path could be a problem too... -- Atentamente, Jaime Casanova Soporte y capacitación de PostgreSQL Asesoría y desarrollo de sistemas Guayaquil - Ecuador Cel. +59387171157