Improving performance with WebSphere eXtreme Scale V7.0 and WebSphere DataPower XC10 Appliance

WebSphere eXtreme Scale is IBM's next generation distributed caching solution based on an in-memory grid that dynamically processes, partitions, replicates, and manages data and business logic across hundreds of servers to support your most demanding business applications.

In a properly tuned WebSphere Commerce environment, most page view requests are served directly from memory cache rather than from much slower and costly accesses to physical disk. As a best practice for ensuring low response times and high transaction throughput, large amounts of server memory are allocated to application cache, within which are stored Commerce artifacts such as pages, page fragments, content objects such as graphics and other JEE presentation layer elements.

In a clustered environment where there are multiple instances of Commerce running, each with its own memory space dedicated to cache for that particular cluster member, cache capacity is limited by the individual JVM size within the cluster. In effect, the total size of any given cache is statically limited to the maximum size as defined in the application server instance.

Furthermore, as nodes are added in order to scale application capacity, each cache associated with a JVM becomes a replica of all the other instances. A side effect of this design is that as each new cluster member starts up, it must build its own cache replica from scratch, which places significant stress on the shared database, and remains limited in size regardless of the numbers of nodes added.

Adding WebSphere eXtreme Scale to the IT environment contributes to performance benefits by addressing a number of design constraints:
  • Elimination of disk storage as a performance bottleneck. One of the potential performance constraints in a Dynacache environment results from processing overhead incurred during the swapping of cache objects paged to disk. Since cache sizes are greatly increased, fewer disk operations are required
  • Reduction of processing overhead and latency associated with exchange of invalidation related information between physically separate cache instances. Since an eXtreme Scale instance is managed as a single addressable memory space without physical partitions between instances, the need to check and invalidate cache objects within each instance in order to maintain consistency (including the network bandwidth penalties typically associated with performing such operations) is entirely eliminated or reduced, depending on the server configuration.
  • Significant reduction in time to reach or return to site steady state after performing full site restart, partial site restart, and complete and/or partial cache invalidation.
WebSphere Commerce Version Commerce Version Commerce Version Commerce Version Commerce Version Commerce Version Commerce supports using the WebSphere DataPower XC10 applicance as well as WebSphere eXtreme Scale to cache JSPs and page fragments.
  • For information about the benefits that can be gained by using both WebSphere eXtreme Scale and WebSphere DataPower XC10 Appliance, see the following white paper: DeveloperWorks article.
  • For information about WebSphere DataPower XC10, refer to the WebSphere DataPower XC10.

For information on WebSphere Commerce support for WebSphere eXtreme Scale and WebSphere DataPower XC10 Appliance, refer to WebSphere Commerce Version 7 software requirements for each operating system.