[pgpool-hackers: 4084] Re: in_hot_standby

[Tatsuo Ishii]

> PostgreSQL 14 introduced new config parameter: in_hot_standby
> https://www.postgresql.org/docs/14/runtime-config-preset.html
> 
> "Reports whether the server is currently in hot standby mode. When
> this is on, all transactions are forced to be read-only. Within a
> session, this can change only if the server is promoted to be
> primary. See Section 27.4 for more information."
> 
> The value is either "on" for standby servers or "off" for primary
> servers. This is sent upon connecting to the server.
> 
> The problem:
> 
> When Pgpool-II connects to PostgreSQL backend servers, in_hot_standby
> is sent as well as other config parameters. Pgpool-II checks each
> config parameter has the same length among servers. Of course
> in_hot_standby has different length depending on whether it's a
> primary server or standby server. As a result each time pgpool
> connects to PostgreSQL following log is recorded.
> 
> 2021-12-16 10:40:34.855: psql pid 366965: LOG:  reading message length
> 2021-12-16 10:40:34.855: psql pid 366965: DETAIL:  message length (22) in slot 1 does not match with slot 0(23)
> 
> This is pretty annoying and I want to eliminate this. An ugly solution
> for this is, check the parameter name and if it's in_hot_standby, then
> skip the check.
> 
> Any better solution?

Pushed to master to 3.7 stable branch.

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