Re: windows shared memory error

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Andrew Dunstan <andrew(at)dunslane(dot)net>
Cc: Magnus Hagander <magnus(at)hagander(dot)net>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: windows shared memory error
Date: 2009-05-04 12:45:34
Message-ID: 27417.1241441134@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Andrew Dunstan <andrew(at)dunslane(dot)net> writes:
> Magnus Hagander wrote:
>> The actual 1 second value was completely random - it fixed all the
>> issues on my test VM at the time. I don't recall exactly the details,
>> but I do recall having to run a lot of tests before I managed to provoke
>> an error, and that with the 1 sec thing i could run it for a day of
>> repeated restarts without any errors.

> Well, my untested hypothesis is that the actual time required is
> variable, depending on environmental factors such as machine load.

Seems reasonable.

> So testing repeatedly where such factors are constant might not be good
> enough. That's why I suggested some sort of increasing backoff, in an
> attempt to be adaptive.

I still think there's absolutely no evidence suggesting that a variable
backoff is necessary. Given how little this code is going to be
exercised in the real world, how long will it take till we find out
if you get it wrong? Use a simple retry loop and be done with it.

regards, tom lane

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2009-05-04 12:57:35 Re: "could not reattach to shared memory" captured in buildfarm
Previous Message Andrew Dunstan 2009-05-04 12:37:53 Re: windows shared memory error