[pgpool-hackers: 3481] Re: Proposal: Simplify WATCHDOG host configurations.

[Tatsuo Ishii]

From: Bo Peng <pengbo at sraoss.co.jp>
Subject: [pgpool-hackers: 3480] Proposal: Simplify WATCHDOG host configurations.
Date: Thu, 19 Dec 2019 15:29:42 +0900
Message-ID: <20191219152942.854fb365a05419557ba6fa93 at sraoss.co.jp>

> Currently the configuration parameters for WATCHDOG such as:
> 
> ---
> wd_hostname
> wd_port
> wd_heartbeat_port
> heartbeat_destination
> heartbeat_destination_port
> other_pgpool_hostname
> other_pgpool_port
> ---
> 
> wd_* are the host and port information about the host itself,
> heartbeat_destination* and other_pgpool_* are the other pgpool information 
> in the cluster.
> 
> This complicates the configuration.
> 
> To simplify WATCHDOG configurations,
> I would like to use a common configuration file for each pgpool node,
> and users just copy the configuration file to another node without editing.
> 
> To implement, each pgpool should detect its own information and sets it to wd_ *,
> Then, set other pgpool's information to heartbeat_destination* and other_pgpool_*.

I am afraid detecting pgpool's own information is not so easy. For
example if we use hostname for it's purpose, it may be different from
wd_hostname if the host which pgpool runs on has multiple
IP/hostname. We need to assign an artificial "host id" to each pgpool
node any way. If so, I think it would be better to eliminate:

> heartbeat_destination
> heartbeat_destination_port
> other_pgpool_hostname
> other_pgpool_port

completely.

Instead we will have "pgpool_node_id" (an integer starting from 0) for
each pgpool node, then we will have:

wd_hostname0
wd_port0
wd_heartbeat_port0
wd_hostname1
wd_port1
wd_heartbeat_port1
wd_hostname2
wd_port2
wd_heartbeat_port2
:
:

Then pgpool.conf could be identical except pgpool_node_id part. Even
we could have pgpool_id.conf file separate from pgpool.conf so that
all pgpool.conf files are identical on each pgpool host.

Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp