[prev in list] [next in list] [prev in thread] [next in thread] 

List:       postgresql-general
Subject:    Re: [GENERAL] PGPool in Master-Master mode, is it possible?
From:       Tatsuo Ishii <ishii () sraoss ! co ! jp>
Date:       2017-11-15 23:03:12
Message-ID: 20171116.080312.1344652738002914432.t-ishii () sraoss ! co ! jp
[Download RAW message or body]

I am not familiar with swarm cluster nor repmgr. So I wonder why you
wouldn't be able to get to the goal you are trying to achieve without
repmgr. Can you please elaborate more?

Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp

> I am also interested in this set-up
> My idea is to run pgpool in a docker swarm cluster and to have two instances of \
> pgpool on different nodes (but not in watchdog mode). In this case it is not \
> possible to give the responsablity to pgpool to do the failover otherwise both \
> instances would try to do the failover (they don't know about each other, no \
> watchdog mode). So I have to set failover_command parameter to an empty string and \
> let repmgr do the automatic failover. I have tested and I believe it is ok: in case \
> of master failure repmgr does the promote, pgpool will not do the failover but will \
> constantly try to reconnect to a new master and as soon as repmgr has done the \
> promotion it is OK. The important think is that when pgpool starts I have to read \
> the state of the cluster in the repmgr metadata table (repl_nodes) and generate the \
> /tmp/pgpool_status file based on that. (I even have to do a promote_node in the \
> edge case that the master is down and was brought down when pgpool also was down).  \
>  But the inconvenient is that if pgpool fails, let's say because the docker node of \
> pgpool is stopped, then docker swarm restart the service on another node but this \
> can take a few seconds. So I would prefer to have multiple pgpool. I did not have \
> the time right now to test such a scenario but I am interested to know if it is \
> possible. Pierre 
> 
> On Wednesday, November 15, 2017, 11:02:31 AM GMT+1, Vikas Sharma \
> <shavikas@gmail.com> wrote:   
> Thank you Tatsuo for the Reply, I will post this in list you mentioned.
> 
> By Master-Master, I meant two pgpool servers both active accepting connections from \
> Application, If one Pgpool Server becomes unlavailable other still accepting \
> connections. At an Ideal time, both Pgpool instances on each PgPool server working \
> actively.  The database in this case will be 1 master and 2 slaves, replicated by \
> streaming replication. 
> Regards
> VS
> 
> On 14 November 2017 at 22:56, Tatsuo Ishii <ishii@sraoss.co.jp> wrote:
> 
> > Hello There,
> > 
> > I need to setup two PGPool Servers in Master-Master mode, First thing I
> > want to know, is it possible?
> > 
> > I know we can setup 2 PGPool servers in master-slave mode using watchdog.
> > http://www.pgpool.net/pgpool- web/contrib_docs/watchdog_ master_slave_3.3/en.html
> > 
> > Could anyone please enlighten me and any workaround for this?
> > 
> > Regards
> > VS
> 
> > I need to setup two PGPool Servers in Master-Master mode, First thing I
> > want to know, is it possible?
> > 
> > I know we can setup 2 PGPool servers in master-slave mode using watchdog.
> > http://www.pgpool.net/pgpool- web/contrib_docs/watchdog_ master_slave_3.3/en.html
> > 
> > Could anyone please enlighten me and any workaround for this?
> 
> This is not an appropriate list. You should go to the Pgpool mailing
> list:
> 
> https://www.pgpool.net/ mailman/listinfo/pgpool- general
> 
> Anyway... I am not sure what you mean by "Master-Master mode" but if
> that means you want to issue write queries by connecting to any of
> Pgpool-II port, it's already possible in the set up you have created.
> 
> Best regards,
> --
> Tatsuo Ishii
> SRA OSS, Inc. Japan
> English: http://www.sraoss.co.jp/index_ en.php
> Japanese:http://www.sraoss.co. jp
> 
> 
> 


-- 
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general


[prev in list] [next in list] [prev in thread] [next in thread]