We've covered a lot of ground in this chapter. Though the size of the API we've covered is relatively small, the knowledge of the semantics behind these methods is important to get the most out of WebSphere eXtreme Scale. We covered the main ObjectMap API methods in detail, while examining the BackingMap configuration options that are all used to make certain agreements in exchange for performance and scalability enhancements.
We also looked at the different lock strategies and what they provide in terms of concurrency and application design. Our methods will look different depending on if a map has an optimistic lock strategy than if it has a pessimistic lock strategy. We learned about the semantics of the get
and getForUpdate
methods and how to apply them to avoid deadlock. A brief example of using a BackingMap
as an "almost"-FIFO queue showed us the getNextKey
method which brought us to the unsupported methods. An ObjectMap can be represented as a java.util.Map
backed by that ObjectMap...