How do you test the consistency models and race conditions on Google App Engine / NDB?
You really need to do testing in the real environment. At best the dev environment is an approximation of production. You certainly can't draw any conclusions at all about performance by just using the SDK.  In many cases the SDK is faster (startup times) and slower (queries on large datasets.  Eventual Consistency is emulated and not 100% the same as production.
Setup: Python, NDB, the GAE datastore. I'm trying to make sure i understand some of the constraints around my data model and its tradeoffs for consistency and max-write-rate. Is there any way to test/benchmark this on staging or on my dev box, or should I just bite the bullet, push to prod on a shadow site of sorts, and write a bunch of scripts?