[pgpool-general: 2528] Re: Sharing PostgreSQL states between PgPool-II instances

[Yugo Nagata]

Hi,

On Mon, 3 Feb 2014 19:45:56 -0600
Theron Luhn <theron at luhn.com> wrote:

> In order to achieve a high level of availability for Postgres, I have two
> Postgres servers (master-standby streaming replication) behind two
> PgPool-II servers.
> 
> I need these two PgPool-II servers to exchange information about the state
> of the Postgres servers, so that one Postgres server doesn't get promoted
> to master by one PgPool-II server, but the other PgPool-II is unaware and
> continues to send queries to the old master.
> 
> To do this I need watchdog correct?

Yes. With watchdog, when a PostgreSQL goes to down, the pgpool which deteced it
inform about this to the other pgpool. So, it comes to that both pgpool doesn't
send queies to the PostgreSQL.
http://www.pgpool.net/pgpool-web/contrib_docs/watchdog_master_slave/en.html

> 
> I've been reading the watchdog docs, and it seems to insist on using a
> virtual IP.  However, virtual IP is not an available option for me.  How
> can I configure watchdog without the virtual IP, just taking advantage of
> information sharing?