Re: windows shared memory error - Mailing list pgsql-hackers

From Tom Lane
Subject Re: windows shared memory error
Date
Msg-id 27417.1241441134@sss.pgh.pa.us
Whole thread Raw
In response to Re: windows shared memory error  (Andrew Dunstan <andrew@dunslane.net>)
Responses Re: windows shared memory error  (Andrew Dunstan <andrew@dunslane.net>)
Re: windows shared memory error  (Magnus Hagander <magnus@hagander.net>)
List pgsql-hackers
Andrew Dunstan <andrew@dunslane.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


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