Concurrency test failures

[Dreamsorcerer]

The memcached test in tests/performance/test_concurrency.py is currently failing with >98% requests failing.

It would be great if anyone has some time to look into debugging this (just need to readd "memcached" to the fixture at the top of the file to start testing it again).

Another problem is when running these tests on Pypy, where only 1 request succeeds on the redis test for some reason (which probably suggests the initial set() call works, but none of the get() calls).

[Dreamsorcerer]

@jayzfbn may look at this.

[jayzfbn]

I sat down for a couple of hours and took a look at this. Took me a bit to get my bearings and in my case I had to dial down the ab params just to get anything to pass; probably some OSX limits being hit as the errors were connection resets. Now I'm getting 91/100 failures consistently for with memcached I will try to dig deeper into where the actual exception is happening.

[Dreamsorcerer]

@jayzfbn Any chance you've found some more time to look into this?

[jayzfbn]

Sorry I'm pretty underwater at the moment.