Re: [HACKERS] Re: [HACKERS] Re: [HACKERS] Re: [HACKERS] Windows service is not starting so there’s message in log: FATAL: "could not create shared memory segment “Global/PostgreSQL.851401618”: Permission denied”

From: Michael Paquier <michael(dot)paquier(at)gmail(dot)com>
To: Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
Cc: Haribabu Kommi <kommi(dot)haribabu(at)gmail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Robert Haas <robertmhaas(at)gmail(dot)com>, Dmitry Vasilyev <d(dot)vasilyev(at)postgrespro(dot)ru>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: [HACKERS] Re: [HACKERS] Re: [HACKERS] Re: [HACKERS] Windows service is not starting so there’s message in log: FATAL: "could not create shared memory segment “Global/PostgreSQL.851401618”: Permission denied”
Date: 2016-05-09 07:17:21
Message-ID: CAB7nPqQHg6z6QotxUUrjF41G4WzZZ01pRpWWjd-hvRHYQn6TGQ@mail.gmail.com
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On Tue, Mar 22, 2016 at 1:56 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> So as far as I can see there are two ways to resolve this issue, one is to
> retry generation of dsm name if CreateFileMapping returns EACCES and second
> is to append data_dir name to dsm name as the same is done for main shared
> memory, that will avoid the error to occur. First approach has minor flaw
> that if CreateFileMapping returns EACCES due to reason other then duplicate
> dsm name which I am not sure is possible to identify, then we should report
> error instead try to regenerate the name
>
> Robert and or others, can you share your opinion on what is the best way to
> proceed for this issue.

For my 2c here, the approach using GetSharedMemName to identify the
origin of a dynamic shared memory segment looks more solid in terms of
robustness and collision handling. Retrying a segment is never going
to be completely water-proof.
--
Michael

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