Re: Recovery test failure for recovery_min_apply_delay on hamster - Mailing list pgsql-hackers

From Michael Paquier
Subject Re: Recovery test failure for recovery_min_apply_delay on hamster
Date
Msg-id CAB7nPqQCVU=_VGTJBH03ccE9topatyZi6YSJFtrG4UPUP=b2yw@mail.gmail.com
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In response to Recovery test failure for recovery_min_apply_delay on hamster  (Michael Paquier <michael.paquier@gmail.com>)
Responses Re: Recovery test failure for recovery_min_apply_delay on hamster  (Alvaro Herrera <alvherre@2ndquadrant.com>)
List pgsql-hackers
On Wed, Mar 2, 2016 at 2:04 PM, Michael Paquier
<michael.paquier@gmail.com> wrote:
> Here are a couple of ways to address this problem:
> 1) Remove the check before applying the delay
> 2) Increase recovery_min_apply_delay to a time that will allow even
> slow machines to see a difference. By experience with the other tests
> 30s would be enough. The sleep time needs to be increased as well,
> making the time taken for the test to run longer
> 3) Remove all together 005, because doing either 1) or 2) reduces the
> value of the test.
> I'd like 1) personally, I still see value in this test.

So, as doing 1) would be actually equivalent to simply having a master
and checking that its standby replicates correctly, I have been
looking at 2) to see to how long the delay has to be set to make the
test failure-proof. After doing some measurements with hamster, 10s
and 15s have proved to not be enough unfortunately, 20s has not failed
in 10 attempts though. Attached is a patch to bump it to 20s, though I
would not complain if the test is actually removed to accelerate the
runs of this test suite.
--
Michael

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