Re: [GENERAL] Streaming Replication Without Downtime - Mailing list pgsql-general

From Venkata B Nagothi
Subject Re: [GENERAL] Streaming Replication Without Downtime
Date
Msg-id CAEyp7J9Yr53PNABRisStbYT2iDo3=wCe01fvyPnBifX68AAcTQ@mail.gmail.com
Whole thread Raw
In response to Fwd: [GENERAL] Streaming Replication Without Downtime  (Gabriel Ortiz Lour <ortiz.admin@gmail.com>)
Responses Re: [GENERAL] Streaming Replication Without Downtime  (Achilleas Mantzios <achill@matrix.gatewaynet.com>)
List pgsql-general

On Tue, Feb 21, 2017 at 6:53 AM, Gabriel Ortiz Lour <ortiz.admin@gmail.com> wrote:
Hi!

  Thanks for pointing out pg_basebackup

  The issue I'm facing now is about missing WAL files.

  What i'm doing:
# su postgres -c 'pg_basebackup -D /var/lib/postgresql/9.1/main/ -x -h master -U sa_rep' ; service postgresql start

  The idea is to call "postgresql start" as soon as pg_basebackup ends.
  But I'm getting the following error:

  FATAL: could not receive data from WAL stream: FATAL: requested WAL segment XXXXXXX has already been removed

  Shoud I just increase 'wal_keep_segments' ?

Yes, that is the way to go. But, you need to know what number you need to increase the wal_keep_segments to ?
Which purely depends on the number of WALs being generated. Which version of PostgreSQL are you using by the way ?
 
  If I do so, do I need do restart the master or just a reload will do it?

No need to restart, "reload" will do.

Venkata B N
Database consultant
 
---------- Forwarded message ----------
From: Achilleas Mantzios <achill@matrix.gatewaynet.com>
Date: 2017-02-17 11:20 GMT-02:00
Subject: Re: [GENERAL] Streaming Replication Without Downtime
To: pgsql-general@postgresql.org


Gabriel you are thinking this in the correct way, but its really :

pg_basebackup -D <your data dir> --write-recovery-conf --progress --xlog-method=stream -h <your primary db server>
then you just edit recovery.conf (if needed), tweak postgersql.conf (if needed) and start the standby .

On 17/02/2017 15:09, Gunnar "Nick" Bluth wrote:
(sorry for the toppost, mobile device)
What you're looking for is pg_basebackup with - - xlog=stream, I guess.

Regards,

Nick


Am 17. Februar 2017 14:06:36 MEZ schrieb Gabriel Ortiz Lour <ortiz.admin@gmail.com>:
Hi all,
  I've been searching for a way to initialize a new Hot Standby node with Streaming Replication withou the need for stop or even restarting the master.
  Of course the master is already with the needed SR configs.

  I know I have to use pg_start_backup/pg_stop_backup, but i'd like some tips, or a link to some tutorial, with the order of the steps.

  I assume will be something like:

-  configure Slave for SR
-  pg_start_backup()
-  rsync PGDATA to slave
-  start PG on the slave
-  pg_stop_backup()

  Anything i'm thinking wrong?

Thanks in advance,
Gabriel

--
Diese Nachricht wurde von meinem Android-Mobiltelefon mit K-9 Mail gesendet.


-- 
Achilleas Mantzios
IT DEV Lead
IT DEPT
Dynacom Tankers Mgmt


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