[pgpool-committers: 8282] pgpool: Suppress message length log for in_hot_standby.

[Tatsuo Ishii]

Suppress message length log for in_hot_standby.

PostgreSQL 14 introduced new config parameter: in_hot_standby
https://www.postgresql.org/docs/14/runtime-config-preset.html
The value is either "on" for standby servers or "off" for primary
servers. As a result pgpool log is fladded by the messages:

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)

To avoid this, only complain if the parameter name is not in_hot_standby.
Also the message is enhanced to show the parameter name.

2022-01-05 13:05:15.993: psql pid 642877: LOG:  ParameterStatus "TimeZone": node 1 message length 30 is different from main node message length 24

Discussion: https://www.pgpool.net/pipermail/pgpool-hackers/2021-December/004077.html

Branch
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V4_2_STABLE

Details
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https://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=17493170fc4ec09b5cbd3c3a3dd855d4032a7ca8

Modified Files
--------------
src/protocol/pool_process_query.c | 30 +++++++++++++++++++++++++-----
src/protocol/pool_proto_modules.c | 39 +++++++++++++++++++++++++++++++++++++--
2 files changed, 62 insertions(+), 7 deletions(-)