[pgpool-hackers: 1814] Re: Fwd: .NET driver throwing error with pgpool ( with client_min_message = debug )

[Tatsuo Ishii]

IMO it's not a bug. It's possible that backend (in this case pgpool)
sends message to frontend even after ReadyForQuery, thus frontend must
be prepared for that situation.

See PostgreSQL manual:

------------------------------------------------------------------
50.2.6. Asynchronous Operations

There are several cases in which the backend will send messages that
are not specifically prompted by the frontend's command
stream. Frontends must be prepared to deal with these messages at any
time, even when not engaged in a query. At minimum, one should check
for these cases before beginning to read a query response.

It is possible for NoticeResponse messages to be generated due to
outside activity; for example, if the database administrator commands
a "fast" database shutdown, the backend will send a NoticeResponse
indicating this fact before closing the connection. Accordingly,
frontends should always be prepared to accept and display
NoticeResponse messages, even when the connection is nominally idle.
------------------------------------------------------------------

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

From: Ahsan Hadi <ahsan.hadi at enterprisedb.com>
Subject: [pgpool-hackers: 1813] Fwd: .NET driver throwing error with
pgpool ( with client_min_message = debug ) Date: Mon, 19 Sep 2016
20:12:46 +0500 Message-ID:
<CAGX_dr2Fyj7hz8kT+dUaag5aE-zZ65fp1DggUPQZB0RkrbTAHQ at mail.gmail.com>

> Can we get this on the pgpool II 3.6 wiki list...
> 
> ---------- Forwarded message ----------
> From: Zahid Khan <zahid.khan at enterprisedb.com>
> Date: Thu, Sep 8, 2016 at 6:44 PM
> Subject: .NET driver throwing error with pgpool ( with client_min_message =
> debug )
> To: pgpool-escalations <pgpool-escalations at enterprisedb.com>
> 
> 
> 
> Customer has reported they have encountered the error when they use .Net
> driver with pgpool debugging enabled ("client_min_message = debug" in
> pgpool.conf).
> 
> Appearently the problem is the .Net driver never expects to receive any
> message from the server after receiving the ReadyForQuery but with client
> debug messages enabled on the pgpool-II side, pgpool-II keep sending the
> debug log messages to the frontend even after sending the ReadyForQuery.
> But it works fine when connected directly to the server becasue server
> doesn't send any extra message after ReadyForQuery.
> 
> Can you please look into this.
> 
> Thanks,
> Zahid K.
> 
> 
> 
> 
> -- 
> Ahsan Hadi
> Snr Director Product Development
> EnterpriseDB Corporation
> The Enterprise Postgres Company
> 
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