Comment 1 for bug 649158

Here is some more background on how to reproduce the problem. Theoretically, you would have to have access to multiple ssh servers to reproduce it, though I'm not sure how many.

I use paramiko on top of the multiprocessing library, using queues to feed tasks to threads. Each thread or worker imports the paramiko module, and using a library we developed for internal use, does RPC on hundreds of linux machines simultaneously. I run 64-128 threads at a time so I'm not sure at what point the issue occurs.