From: Tom Lane <tgl@sss.pgh.pa.us>
To: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Fabien COELHO <coelho@cri.ensmp.fr>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: libpq async duplicate error results
Date: Fri, 06 May 2022 10:28:53 -0400
Message-ID: <2889550.1651847333@sss.pgh.pa.us> (raw)
In-Reply-To: <de57761c-b99b-3435-b0a6-474c72b1149a@enterprisedb.com>
References: <202202081500.xl3iwa7doscz@alvherre.pgsql>
<394797.1645388816@sss.pgh.pa.us>
<1262938.1645658107@sss.pgh.pa.us>
<1421785.1645723238@sss.pgh.pa.us>
<de57761c-b99b-3435-b0a6-474c72b1149a@enterprisedb.com>
Peter Eisentraut <peter.eisentraut@enterprisedb.com> writes:
> I took another look at this. The output from the test program at the
> beginning of the thread is now (master branch):
> ...
> command = SELECT 'after';
> PQsendQuery() error: FATAL: terminating connection due to administrator
> command
> server closed the connection unexpectedly
> This probably means the server terminated abnormally
> before or while processing the request.
> no connection to the server
> It appears the "after" query is getting the error message from the
> previous cycle somehow.
What is happening is that this bit in PQsendQueryStart is deciding
not to clear the message buffer because conn->cmd_queue_head isn't
NULL:
/*
* If this is the beginning of a query cycle, reset the error state.
* However, in pipeline mode with something already queued, the error
* buffer belongs to that command and we shouldn't clear it.
*/
if (newQuery && conn->cmd_queue_head == NULL)
pqClearConnErrorState(conn);
So apparently the fault is with the pipelined-query logic. I'm
not sure what cleanup step is missing though.
regards, tom lane
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To: pgsql-hackers@postgresql.org
Cc: tgl@sss.pgh.pa.us, peter.eisentraut@enterprisedb.com, alvherre@alvh.no-ip.org, coelho@cri.ensmp.fr
Subject: Re: libpq async duplicate error results
In-Reply-To: <2889550.1651847333@sss.pgh.pa.us>
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