[Pgpool-general] installing and configuring pgpool-II

[Yoshiyuki Asaba]

Hi,

From: Richard Yen <dba at richyen.com>
Subject: [Pgpool-general] installing and configuring pgpool-II
Date: Thu, 26 Apr 2007 11:16:09 -0700

> Primarily, I'm looking to figure out the following, just to get me  
> started:
> 
> 1. What's the difference between system_db_* and backend_* parameters  
> for the pgpool.conf file?

system_db_* are for parallel mode. If you set up replication mode, you
need not to set up system_db_*.


> 2. How do I get replication working?  Do I need to set up the same  
> data schema on all nodes and just let it go, or do I need to set up a  
> separate replication schema, much like how Slony-I does it?

You need to set up the same schema on all nodes. Or you send DML
queries to pgpool. pgpool replicates them to all nodes.


> 3. How do I get connection pooling to work?  I started pgpool-II up  
> with the following backend parameters, but I always get connected to  
> db1-dev:

Do you set the following parameter in pgpool.conf?

  connection_cache = true


> > # system DB info
> > system_db_hostname = 'db1-dev'
> > system_db_port = 5432
> > system_db_dbname = 'pgpool'
> > system_db_schema = 'pgpool_catalog'
> > system_db_user = 'pgpool'
> > system_db_password = ''
> >
> > # backend_hostname, backend_port, backend_weight
> > # here are examples
> > backend_hostname1 = 'db2-dev'
> > backend_port1     = 5432
> > backend_weight1   = 1
> >
> > backend_hostname2 = 'db3-dev'
> > backend_port2     = 5432
> > backend_weight2   = 1
> >
> > backend_hostname3 = 'db4-dev'
> > backend_port3     = 5432
> > backend_weight3   = 5
> >

If you want to set replication, you set the parameters in pgpool.conf.

  backend_hostname0 = 'db1-dev'
  backend_port0 = 5432
  backend_weight0 = 1
  backend_hostname1 = 'db1-dev'
  backend_port1 = 5432
  backend_weight1 = 1
  backend_hostname2 = 'db1-dev'
  backend_port2 = 5432
  backend_weight2 = 1
  backend_hostname3 = 'db1-dev'
  backend_port3 = 5432
  backend_weight3 = 1

  replication_mode = true
  replication_strict = true

Regards,
--
Yoshiyuki Asaba
y-asaba at sraoss.co.jp