Thread: Setup Pgpool2 with Postgresql Streaming Replication

Setup Pgpool2 with Postgresql Streaming Replication

From
alanhi
Date:
Hi,

I'm following the steps from:

https://access.crunchydata.com/documentation/pgpool/4.0.0/example-cluster.html

I'm at step 7.3.8.1 Set up PostgreSQL standby server:
Ran this command on the primary server: pcp_recovery_node -h 192.168.80.90
-p 9898 -U postgres -n 1
And received this error: 
ERROR:  recovery is checking if postmaster is started
DETAIL:  postmaster on hostname:"ltpgsql12" database:"template1"
user:"postgres" failed to start in 90 second

How can I get this command to run successfully?

Also, when I ran this command: psql -p 5433 -c "show pool_nodes"
It shows the following pgpool2 node status, but when I did a listing of
databases on the primary and standby servers, I don't see the databases on
the primary replicated to the standby.  How can I setup the Postgresql
Streaming Replication and check if it's working?

node_id | hostname  | port | status | lb_weight |  role   | select_cnt |
load_balance_node | replication_delay | replication_state |
replication_sync_state | last_status_change

---------+-----------+------+--------+-----------+---------+------------+-------------------+-------------------+-------------------+------------------------+---------------------
 0       | ltpgsql11 | 6432 | up     | 0.500000  | primary | 0          |
true              | 0                 |                   |                       
| 2020-10-21 11:56:48
 1       | ltpgsql12 | 6432 | down   | 0.500000  | standby | 0          |
false             | 0                 |                   |                       
| 2020-10-21 11:56:48
(2 rows)


Thanks,
Alan



--
Sent from: https://www.postgresql-archive.org/PostgreSQL-general-f1843780.html



Re: Setup Pgpool2 with Postgresql Streaming Replication

From
Tatsuo Ishii
Date:
Hi Alan,

This is not the best forum to discuss Pgpool-II related topics. I
advice you to go to the Pgpool-II dedicated forum:

https://www.pgpool.net/mailman/listinfo/pgpool-general

> Hi,
> 
> I'm following the steps from:
> 
> https://access.crunchydata.com/documentation/pgpool/4.0.0/example-cluster.html

This documentation looks pretty old. The original and the latest
documentation for Pgpool-II 4.0 is here (I assume you are using
Pgpool-II 4.0):

https://www.pgpool.net/docs/40/en/html/example-cluster.html

I strongly suggest to look into this.

> I'm at step 7.3.8.1 Set up PostgreSQL standby server:
> Ran this command on the primary server: pcp_recovery_node -h 192.168.80.90
> -p 9898 -U postgres -n 1
> And received this error: 
> ERROR:  recovery is checking if postmaster is started
> DETAIL:  postmaster on hostname:"ltpgsql12" database:"template1"
> user:"postgres" failed to start in 90 second
> 
> How can I get this command to run successfully?

Probably you have a problem with ssh settings. The newer and original
document describes far detailed steps to set up ssh settings. Please
take a look at "7.3.2. Requirements" section in the newer document.

In the mean time to confirm that the problem is related to ssh, we
need to look into the PostgreSQL log (not Pgpool-II log) on primary
PostgreSQL node. Please share it (again, you'd better to post messages
to the pgpool-general mailing list).

> Also, when I ran this command: psql -p 5433 -c "show pool_nodes"
> It shows the following pgpool2 node status, but when I did a listing of
> databases on the primary and standby servers, I don't see the databases on
> the primary replicated to the standby.  How can I setup the Postgresql
> Streaming Replication and check if it's working?

Standby status is down because you failed to execute online
recovery. You need to fix it.

> node_id | hostname  | port | status | lb_weight |  role   | select_cnt |
> load_balance_node | replication_delay | replication_state |
> replication_sync_state | last_status_change
>
---------+-----------+------+--------+-----------+---------+------------+-------------------+-------------------+-------------------+------------------------+---------------------
>  0       | ltpgsql11 | 6432 | up     | 0.500000  | primary | 0          |
> true              | 0                 |                   |                       
> | 2020-10-21 11:56:48
>  1       | ltpgsql12 | 6432 | down   | 0.500000  | standby | 0          |
> false             | 0                 |                   |                       
> | 2020-10-21 11:56:48
> (2 rows)
> 
> 
> Thanks,
> Alan
> 
> 
> 
> --
> Sent from: https://www.postgresql-archive.org/PostgreSQL-general-f1843780.html
> 
>