Concurrency and SimpleDB

The power of SimpleDB becomes truly apparent when you start taking advantage of the support for concurrency by writing multithreaded programs for interacting with it. You can choose the SimpleDB operation that you like—inserting items, deleting items, updating items, and easily scale it up using boto and the parallelization techniques that we looked at in this chapter.

There are some things that you really need to be aware of when using concurrency with SimpleDB:

• If you make a large number of concurrent SimpleDB calls, it can sometimes result in Service Unavailable (503) responses from SimpleDB. Your application must be aware of this fact and handle this by retrying the request with an exponential back-off.

• Here is a blog post that argues a position opposite from the above and makes a good case why using exponential back-off is not a good strategy when performing concurrent operations on SimpleDB— http://www.daemonology.net/blog/2008-06-29-high-performance-simpledb...