Thread: [GENERAL] WAL history files - Pgsql 9.2

[GENERAL] WAL history files - Pgsql 9.2

From
Patrick B
Date:
Hi guys,

Are the history files copied with the wal_files? Or I have to do it separated? 

00000003.history': No such file or directory


I'm using PostgreSQL 9.2.
Cheers
Patrick

Re: [GENERAL] WAL history files - Pgsql 9.2

From
Venkata B Nagothi
Date:

On Mon, Dec 12, 2016 at 7:48 AM, Patrick B <patrickbakerbr@gmail.com> wrote:
Hi guys,

Are the history files copied with the wal_files? Or I have to do it separated? 

00000003.history': No such file or directory


I'm using PostgreSQL 9.2.

Can you please explain the scenario you are referring to ? during streaming replication ? or during standby promotion ?

Regards,

Venkata B N
Database Consultant

Re: [GENERAL] WAL history files - Pgsql 9.2

From
Patrick B
Date:
2016-12-12 12:00 GMT+13:00 Venkata B Nagothi <nag1010@gmail.com>:

On Mon, Dec 12, 2016 at 7:48 AM, Patrick B <patrickbakerbr@gmail.com> wrote:
Hi guys,

Are the history files copied with the wal_files? Or I have to do it separated? 

00000003.history': No such file or directory


I'm using PostgreSQL 9.2.

Can you please explain the scenario you are referring to ? during streaming replication ? or during standby promotion ?





Sure...

I've got:

> Master01 (sending wal_files to the slaves)
> slave01 (streaming replication from master01 + wal_files)
> slave02 (streaming replication from master01 + wal_files)

I'll turn slave01 into a master; on recovery.conf:

trigger_file = '/tmp/pg_failover_trigger';touch /tmp/pg_failover_trigger


Then, the new scenario will be:

> slave01 (NEW MASTER)
> slave02 (streaming replication from slave01 + wal_files)


Will slave02 be able to switch the timeline using wal_files provided by the new master?
Thanks
 

Re: [GENERAL] WAL history files - Pgsql 9.2

From
Patrick B
Date:


2016-12-12 12:09 GMT+13:00 Patrick B <patrickbakerbr@gmail.com>:
2016-12-12 12:00 GMT+13:00 Venkata B Nagothi <nag1010@gmail.com>:

On Mon, Dec 12, 2016 at 7:48 AM, Patrick B <patrickbakerbr@gmail.com> wrote:
Hi guys,

Are the history files copied with the wal_files? Or I have to do it separated? 

00000003.history': No such file or directory


I'm using PostgreSQL 9.2.

Can you please explain the scenario you are referring to ? during streaming replication ? or during standby promotion ?





Sure...

I've got:

> Master01 (sending wal_files to the slaves)
> slave01 (streaming replication from master01 + wal_files)
> slave02 (streaming replication from master01 + wal_files)

I'll turn slave01 into a master; on recovery.conf:

trigger_file = '/tmp/pg_failover_trigger';touch /tmp/pg_failover_trigger


Then, the new scenario will be:

> slave01 (NEW MASTER)
> slave02 (streaming replication from slave01 + wal_files)


Will slave02 be able to switch the timeline using wal_files provided by the new master?
Thanks
 

No.. it didn't copy. i tested here. I had to manually copy the history file from /var/lib/pgsql/9.2/data/pg_xlogs from the new master to the same directory on the slaves.

Re: [GENERAL] WAL history files - Pgsql 9.2

From
Michael Paquier
Date:
On Mon, Dec 12, 2016 at 9:31 AM, Patrick B <patrickbakerbr@gmail.com> wrote:
> No.. it didn't copy. i tested here. I had to manually copy the history file
> from /var/lib/pgsql/9.2/data/pg_xlogs from the new master to the same
> directory on the slaves.

An archive command is able to properly fetch the history files to
define a new timeline. If you rely only on streaming replication, only
9.3 and newer versions are able to do that: the replication protocol
has been extended at this point to allow a standby to fetch from a
primary history files.
--
Michael