Re: Very poor performance when checking out large number of binary files

On Monday 27 Sep 2010, Niklas Deutschmann wrote:
> The performance of Subversion when checking out large number of files in
> a single directory becomes extremely poor when the svn:mime-type
> property is set to some binary MIME type.
>
> Steps to reproduce:
>
> 1. Create a project that contains a few thousand small files in a single
> directory that have no svn:mime-type property set.
>
> 2. Check out project
>
> 3. Set svn:mime-type property to some MIME type that indicates a binary
> file (application/xyz) and commit
>
> 4. Check out project
>
> The second checkout takes *dramatically* longer. Some numbers (project
> with 3500 files, each ~1KB)
>
> - no MIME type: ~2 minutes
> - "binary" MIME type: >10 minutes (79% after 10 minutes, getting slower
> and slower for each file)
>
> We are using Subversion 1.6.6. The problem occurs
> - with the command line client
> - with the Subclipse Eclipse plugin (Eclipse 3.6) when the JavaHL client
> library is used.
> - with both the svn:// and the http:// protocol
>
> The problem does *not* occur with Subclipse and the svnkit library
>
> Niklas

I'm currently trying to reproduce this as I'm interested in this type of
problem but I'm having difficulty with svn 1.6 and am time constrained so
will give it another shot later. Not really helpful and more discussion than
anything but it sounds a lot like a common performance gotcha that appears
when abnormal conditions are met such as this. Somewhere there is a list that
is being linearly searched and added to as each entry of the directory is
checked out. The problem is, it might turn out the solution to that slows
down the typical case too much.

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