• Ceiling of 2 - Calculates primes up to a max of 2, then on next request 4, 8, 16, etc. Does not die opaquely--when request should fail, instead the request returns, but counter (global scope) reset. This happens at 524288.
• Ceiling of 4 - Calculates primes up to a max of 4, then on next request 16, 64, etc. Same effect as Ceiling of 2, but reached faster.
• Ceiling of 524288 - Calculates primes up to a max of 524288. Dies with MemoryError. Odd because this should act the same as the last erroring request of the above 2.
• Make 10 calls from AppEngine to AppEngine using UrlFetch. This was dies with DeadlineExceededError.
• Try making threads - Runs great at 20 threads!
• Try making more threads - How about 20k threads! Dies with DeadlineExceededError after making 1346 threads. Got some great warnings in the log on this one. Looks like AppEngine confused some of the immediately following requests with the actual culprit:
  
• A few other gems... going to my dashboard and selecting my info logs gives me an error (too much in my logs already?): HTTP response was too large: 1205412. The limit is: 1048576..
• The thread-generating requests are being terminated about around 1s of operation--which incedentally means that Google's AppEngine is limited now to 1400 new threads/sec.
• My BlackBook completed the 20k threads run in 8 seconds yielding a comparison thread rate of 2.5k threads/sec:
  

  curl -O http://localhost:8080/thread-test-20k
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                   Dload  Upload   Total   Spent    Left  Speed
  100  2363  100  2363    0     0    268      0  0:00:08  0:00:08 --:--:--   620
  

Ceiling:

Time:

Data: