From: Tom Lane <tgl@sss.pgh.pa.us>
To: Amit Kapila <amit.kapila16@gmail.com>
cc: Michael Paquier <michael@paquier.xyz>,
        PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: YA race condition in 001_stream_rep.pl (was Re: pgsql: Allow
 using the updated tuple while moving it to a different par)
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Comments: In-reply-to Amit Kapila <amit.kapila16@gmail.com>
	message dated "Sun, 15 Jul 2018 16:39:50 +0530"
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Date: Wed, 18 Jul 2018 17:42:40 -0400
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Amit Kapila <amit.kapila16@gmail.com> writes:
> On Sat, Jul 14, 2018 at 11:46 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> So the issue boils down to this: the test script is, effectively,
>> assuming that it's guaranteed that the walreceiver will send a feedback
>> message before it shuts down; but there is no such guarantee.  Is this
>> a bug in the test script, or a bug in the walreceiver logic?  I can
>> see the value of having such a guarantee, but I also think it would be
>> nigh impossible to make it a bulletproof guarantee.  We could perhaps
>> add "XLogWalRcvSendHSFeedback(true)" somewhere closer to process exit,
>> but that might add more failure modes than it removes.
>> 
>> Or we could change the test script to wait for feedback before it
>> issues the shutdown, but then I think the test is a bit pointless.

We've seen two more instances of this failure in the buildfarm since
this exchange (dragonet and flaviventris --- seems like Andres' menagerie
is particularly prone to it).

> Currently, neither the code nor our documentation suggests that we can
> expect HSFeedback before the shutdown, so it is better to adjust the
> test.  If the sole purpose of the test is to test feedback after
> shutdown, then it is worth considering to remove the test altogether.

Hearing nobody speaking in favor of the other alternatives,
I've removed the test.

			regards, tom lane