Horton

RE: Libpq support to connect to standby server as priority

Tsunakawa, Takayuki <tsunakawa.takay@jp.fujitsu.com>

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From: "Tsunakawa, Takayuki" <tsunakawa.takay@jp.fujitsu.com>
To: 'Dave Cramer' <pg@fastcrypt.com>, Tatsuo Ishii <ishii@sraoss.co.jp>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Robert Haas <robertmhaas@gmail.com>, "Laurenz Albe" <laurenz.albe@cybertec.at>, Haribabu Kommi <kommi.haribabu@gmail.com>, Jing Wang <jingwangian@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2019-01-18T00:08:45Z
Lists: pgsql-hackers 
From: Dave Cramer [mailto:pg@fastcrypt.com]
> 	>> 2) If there's no node on which pg_is_in_recovery() returns false,
> then
> 	>>    we need to retry until we find it. To not retry forever, there
> 	>>    should be a timeout counter parameter.

> Checking the code I see we actually use show transaction_read_only.

Also, does PgJDBC really repeat connection attempts for a user-specified duration?  Having a quick look at the code, it seemed to try each host once in a while loop.


Regards
Takayuki Tsunakawa

Commits

  1. Make test_target_session_attrs more robust against connection failure.

  2. Extend the abilities of libpq's target_session_attrs parameter.

  3. Mark default_transaction_read_only as GUC_REPORT.

  4. Introduce a new GUC_REPORT setting "in_hot_standby".

  5. Avoid spamming the client with multiple ParameterStatus messages.

  6. Avoid harmless Valgrind no-buffer-pin errors.

  7. Restructure libpq code to remove some duplicity

  8. libpq: Add target_session_attrs parameter.