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AW: failure of creating mutex file on pending delete

From: Matthias Ludwig <matthias-ludwig_at_gmx.net>
Date: Sat, 8 Nov 2014 01:32:07 +0100

He there,

I don't have any clue oft he development of svn, nevertheless I try to make some assumptions. Please correct me if I'm wrong.

I might obverved a problem:

I'm usging Apache mod_dav_svn 1.8.10 on windows 7.

In my apache error log files I found the errors:

(20014)Internal error: -Can't open file 'C:\\ServerData\\svn\\repos\\db\\rev-prop-atomics.mutex': access denied
(20014)Internal error: Revprop caching for 'C:/ServerData/svn/repos/db' disabled because SHM infrastructure for revprop caching failed to initialize.

They appear when I open TortoiseSvn-Repo-Browser (which means that a lot of request are send tot he server. (maybe even parallel? I don't know)

The apache run under local System account. I've checked the file permissions on all repo-files for user SYSTEM. Everything is ok.

Then I used "Process Monitor" from Sysinternals to check the file access on the file above (http://technet.microsoft.com/en-us/sysinternals/bb842062.aspx)
I saw hundreds of failures of file creation, with the result "DELETE PENDING"

20:08:43,2589409 httpd.exe 3728 CreateFile C:\ServerData\svn\repos\db\rev-prop-atomics.mutex DELETE PENDING Desired Access: Read Attributes, Delete, Disposition: Open, Options: Non-

Googling around I found out that an attempt to create a file with a "Pending Delete" can lead to an "access denied" result. (e.g. http://stackoverflow.com/questions/3764072/c-win32-how-to-wait-for-a-pending-delete-to-complete)

Is there a relation to the error-Log-Message? The timing said so.

I suppose the create/lock/unlock/delete command on that file are used for synchronization.
What are the performance costs of synchronization with the file? When I I see the error file creation failure I get the feeling there is a performance loss there. The Tortoise-SVN-Repo browser in our setting is quit slow. Is there a relation?
Maybe a named mutex of he Win32-API would be the better choice for synchonization because they are made for that reason. (http://msdn.microsoft.com/en-us/library/windows/desktop/ms682411(v=vs.85).aspx)

But as a said I dont know anyting oft he svn-development. I'm curious what the expert's say to my observation.

Looking forward for any response.
Thank you.
Cheers
Matthias
Received on 2014-11-10 07:10:55 CET

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