As a follow-up to the follow up, I'd like to put in a little testimonial.
This issue is something that has plagued us for a long time... and of course things got worse during the busy season, right when we needed things to go faster. I had assumed for a while that my users were just hitting the fileserver hard, but when I finally delved into the problem, I discovered the issue with Photoshop doing file accesses that proved inefficient in conjunction with the AFS Windows client. After submitting a bug report and a little bit of back and forth to get a handle on what the problem really was, Jeffrey did some research and uncovered the underlying issue. From this, we were able to come up with a short-term workaround for the really problematic places, and we chose to fund the development effort to fix the underlying issue so that all the places where we had some large directory fan-out wouldn't continue to slow us down. (We weren't going to build workarounds for every directory.) In less than a week, Jeffrey had a build ready for us to test, and the results were exactly what we needed. Where before images had been loading at speeds of over 5 seconds per image (even if the images were in the cache!), now they were loading in a second or two. We didn't know whether to laugh or cry.... (no more coffee breaks waiting for Photoshop to load 20 images). I've thanked Jeffrey personally, and I'd also like to do so publicly. Getting the work done was a graceful process, and well worth my time and the funds allocated to the project. It makes our job so much lighter when we stop getting complaints, and instead we get comments like, "What did you do? AFS is so much faster!" We're in the process of distributing the build, and I'm sure I'll have more to say when we get feedback from our users. As always, we appreciate all who contribute to Open Source initiatives in any way... whether it's coding, testing, writing up bug reports so the product can be improved, or funding. Everyone benefits. Special thanks to the gatekeepers who continue to maintain and improve OpenAFS as a truly outstanding product. -- Michael Polek Director of System Operations 1580 Francisco Street, Suite 101 Torrance, CA 90501 http://www.pictage.com Jeffrey Altman wrote:
As a follow-up, I have spent the last few weeks working on this issue. Indeed, Photoshop's behavior is hideous but that doesn't mean that OpenAFS couldn't be more efficient.
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With this change, the performance of Photoshop on directory trees with large numbers of entries becomes more than reasonable. 250MB JPGs open in about two seconds of clock time when stored in a three directory deep tree. At the same time AFS client service CPU utilization remains in the single digits instead of using 99% of a single processor.
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I wish to thank Pictage for funding this research and development that the entire community in going to benefit from. These changes will appear in 1.5.13. Jeffrey Altman Secure Endpoints Inc.
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