Re: windows shared memory error

From: Andrew Dunstan <andrew(at)dunslane(dot)net>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: windows shared memory error
Date: 2009-05-01 22:42:35
Message-ID: 49FB7ADB.9040701@dunslane.net
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Tom Lane wrote:
> Andrew Dunstan <andrew(at)dunslane(dot)net> writes:
>
>> It strikes me that we really need to try reconnecting to the shared
>> memory here several times, and maybe the backoff need to increase each
>> time.
>>
>
> Adding a backoff would make the code significantly more complex, with
> no gain that I can see. Just loop a few times around the
> one-second-sleep-and-retry logic.
>
> I concur with Greg's opinion that the need for a sleep here at all
> is pretty fishy, but I doubt anyone really cares enough to find out
> exactly what's happening (and it being Windows, there may be no better
> solution anyway ...)
>
>
>

We've seen similar things with other Windows file operations, IIRC. What
bothers me is that the problem might be precisely because the 1 second
sleep between the CloseHandle() call and the CreateFileMapping() call
might not be enough due to system load, so repeating the cycle without
increasing the sleep period will just repeat the error.

cheers

andrew

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