[pgpool-general: 7193] Re: The best way to enable PgPool and PostgreSQL server start automatically in the Pgpool + WatchDog Mode

[J.L.]

Hi Bo,
In fact the I only start pgpool service in all servers with
systemctl start pgpool

And only start the postgres on the primary with
systemctl start postgresql-12

The postgres service started on server 2 & 3 as replication is to execute
pcp_recovery_node command with specify the VIP as the host the same as the
official guidance:
8.3.7.1. Set up PostgreSQL standby server

    # pcp_recovery_node -h 192.168.137.150 -p 9898 -U pgpool -n 1
    Password:
    pcp_recovery_node -- Command Successful

    # pcp_recovery_node -h 192.168.137.150 -p 9898 -U pgpool -n 2
    Password:
    pcp_recovery_node -- Command Successful


The configuration of pgpool is nearly the same with
https://www.pgpool.net/docs/latest/en/html/example-cluster.html#EXAMPLE-CLUSTER-PRE-SETUP

Thanks.
.

On Tue, Aug 11, 2020 at 10:47 PM Bo Peng <pengbo at sraoss.co.jp> wrote:

> Hi,
>
> On Sun, 9 Aug 2020 17:05:01 +0800
> "J.L." <wantdrink at gmail.com> wrote:
>
> > Hi there,
> >
> > I've installed pgpool 4.1.2 and postgresql 12.3 with watchdog based on
> > https://www.pgpool.net/docs/latest/en/html/example-cluster.html.
> > That is 3 machines with a VIP, pgpool service + watchdog service +
> > postgresql service running on each of them, 1 primary + 2 standby
> > postgresql.
> > The question is: is that possible to enable those services as auto
> started
> > even if I reboot all of them?
> >
> > I checked running services on them:
> >
> > [root at primary ~]# systemctl status postgresql-12
> > > postgresql-12.service - PostgreSQL 12 database server
> > >    Loaded: loaded (/usr/lib/systemd/system/postgresql-12.service;
> > > disabled; vendor preset: disabled)
> > >    Active: active (running) since Thu 2020-07-02 22:17:35 CDT; 1
> months 6
> > > days ago
> > >
> > > [root at secondary1 ~]# systemctl status postgresql-12
> > > postgresql-12.service - PostgreSQL 12 database server
> > >    Loaded: loaded (/usr/lib/systemd/system/postgresql-12.service;
> > > disabled; vendor preset: disabled)
> > >    Active: inactive (dead)
> > >
> > > [root at secondary2 ~]# systemctl status postgresql-12
> > > postgresql-12.service - PostgreSQL 12 database server
> > >    Loaded: loaded (/usr/lib/systemd/system/postgresql-12.service;
> > > disabled; vendor preset: disabled)
> > >    Active: inactive (dead)
> >
> >
> > So the postgresql service on secondary 1 & 2 is not started by postgresql
> > service, they are triggered by pgpool with command like:
> >
> > > /usr/pgsql-12/bin/postgres -D /var/lib/pgsql/12/data
>
> Sorry, I could not understand the configuration.
> May I ask how you configure pgpool to execute command above?
>
> > And on the primary the ps aux shows
> >
> > > /usr/pgsql-12/bin/postmaster -D /var/lib/pgsql/12/data/
> >
> >
> > Which means I can enable pgpool service on all 3 machines:
> >
> > > systemctl enable pgpool
> >
> >
> > But shouldn't do the same for postgresql service like systemctl enable
> > postgresql-12.
> > Also I'm not sure if enabling services to start automatically will lead
> to
> > any issue.
> >
> > Any suggestion or guidance about this is appreciated. I just want to make
> > the DB system recover even after rebooting.
> >
> > Thanks.
>
>
> --
> Bo Peng <pengbo at sraoss.co.jp>
> SRA OSS, Inc. Japan
>
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