Re: pgbench small bug fix

From: Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr>
To: Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>
Cc: Aleksander Alekseev <a(dot)alekseev(at)postgrespro(dot)ru>, Robert Haas <robertmhaas(at)gmail(dot)com>, PostgreSQL Developers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: pgbench small bug fix
Date: 2016-03-04 18:58:07
Message-ID: alpine.DEB.2.10.1603041954540.11128@sto
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers


>>> You're probably right, but TBH I'm pretty unsure about this whole thing.
>>
>> If the question is "is there a bug", then answer is yes. The progress report
>> may disappear if thread 0 happens to stop, even of all other threads go on.
>> Obviously it only concerns slow queries, but there is no reason why pgbench
>> should not work with slow queries. I can imagin good reason to do that, say
>> to check the impact of such queries on an OLTP load.
>>
>> The bug can be kept instead, and it can be called a feature.
>
> No, I agree that this looks like a bug and that we should fix it; for
> example, if all connections from thread 0 terminate for some reason,
> there will be no more reports, even if the other threads continue.
> That's bad too.
>
> What I'm unsure about is the proposed fix.
>
>>> I will leave it alone for the time being.
>>
>> Maybe you could consider pushing the first part of the patch, which stops if
>> a transaction is scheduled after the end of the run? Or is this part
>> bothering you as well?
>
> So there are *two* bugs here?

Hmmm... AFAICR, maybe fixing the first creates the second issue, i.e.
maybe the second issue is currently hidden by the thread going on after
the end of the run, so the second is just a latent bug that cannot be
encountered.

I'm not sure whether I'm very clear:-)

--
Fabien.

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Robert Haas 2016-03-04 19:14:31 Re: transam README small fix
Previous Message Robert Haas 2016-03-04 18:56:23 Re: Logic problem in SerializeSnapshot()