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Re: "SVNAuthorizationShortCircuit or something similar"

From: David James <james_at_cs.toronto.edu>
Date: 2007-04-12 21:02:31 CEST

On 4/12/07, Josh Gilkerson <jwg@google.com> wrote:
> Since some sites need the performance soon, I have written a first
> draft of a change that will add a mechanism to bypass the generation
> of apache subrequests. I have not had time to test it except to make
> sure it compiles.
>
> Any comments/criticisms are more than welcome. I will update this
> thread concerning the testing and debugging once I have time to do
> some.

Hi Josh,

With your patch, a request for a log message would still generate 1
lookup per file affected in the revision. If a revision affects, say,
a hundred thousand files, your patch would still trigger a hundred
thousand provider lookups and a hundred thousand calls to said
provider when a user requests to look at the log message.

What is the overhead of a provider lookup and call as compared to a
regular function call? If it's not a lot more expensive then maybe
this is not an issue.

Try importing a hundred thousand files in a single revision into a
repository, and then running 'svn log' on any file on the repository.
If you do this using ra_svn you'll find that there are no performance
issues, even with authz enabled. Without your patch, ra_dav takes
about 30-90 minutes to calculate all of the authz lookups in this
scenario.

I'd be curious to see how much your patch helps.

Cheers,

David

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Received on Thu Apr 12 21:02:42 2007

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