[pgpool-general: 9350] Re: pgpool 4.5.5 can't reach stand by server

[Tatsuo Ishii]

> From the master node (192.168.0.160) I can connect to the server1, the
> stand by server
> 
> [postgres at buda pgpool-II]$ psql -h 192.168.0.162 -U postgres -p 5434
> Contraseña para usuario postgres:
> psql (17.2)
> Digite «help» para obtener ayuda.
> postgres=# \q
> 
> [postgres at buda pgpool-II]$ pcp_attach_node -p 9898 -h 192.168.0.162 -n 1 -U
> postgres
> ERROR: connection to host "192.168.0.162" failed with error "No route to
> host"
> 
> In pgpool.con, the pcp parameters are:
> 
> pcp_listen_addresses = '*'
>  #pcp_port = 9898
>  pcp_socket_dir = '/var/run/postgresql'
>  #log_pcp_processes = on

The pcp_attach_node command needs to connect to pgpool, not standby
PostgreSQL server. So you should run the command on 192.168.0.160 with
command line: pcp_attach_node -p 9898 -h localhost 1

> Even if the attaching process would work, I don't understand why it is
> necessary and pgpool don't try to reach stand by server at the starting up
> time.

Because pgpool remembers that node 1 (standby) was down. You need to
teach pgpool that now node 1 comes up. This is intentional to not
automatically attach broken server.

> By de the way, for me was not easy install pgpool. The process failed
> because inexistent library libmemcached.so.11. After a while I could reach
> the correct rpm from
> https://oraclelinux.pkgs.org/9/ol9-codeready-builder-x86_64/libmemcached-awesome-1.1.0-12.el9.x86_64.rpm.html
> 
>  dnf install ./libmemcached-awesome-1.1.0-12.el9.x86_64.rpm
> 
> After installing the library and editing
> /etc/yum.repos.d/pgdg-redhat-all.repo adding exclude=pgpool* in each
> postgresql section
> I could install pgpool.

Maybe you are using RPM which is not Pgpool-II community RPM?

https://www.pgpool.net/yum/

BTW you seem to set backend_hostname0 = 'localhost', which is not
recommended. You'd better to set backend_hostname0 = '192.169.0.160'
instead.

Best reagards,
--
Tatsuo Ishii
SRA OSS K.K.
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp