IBM SG24-6320-00 manual Https//hostname8002/cachemonitor

6320ch_sum_of_changes.fm Draft Document for Review July 28, 2004 7:33 pm

multiple users or pages. Fragments should be stable over a long enough period of time for meaningful reuse to occur.

The goal of fragment caching with DynaCache is to maximize fragment reusability and cache utilization by breaking a page into smaller and simpler page fragments. This makes any caching, even a highly dynamic page, possible.

The caching should take place as close to the user as possible, taking into consideration security and personalized data factors. For example, non-user specific data can be place closest to the user (like on an Edge Server), but secure information should be placed behind a firewall. Pages need to be fragmented out as much as possible so they can be cached at different locations. The order for placing this from close to far is: Edge server, IBM HTTP Server, WebSphere Application Server, Database Server.

WebSphere Commerce has dynamic cache enabled by default, but the cachespec.xml contains no entries for any of the provided business models. Instead, sample subsets of cachespec.xml files are provided to enable caching of the business models. They also support invalidation using different techniques.

WebSphere Commerce comes with a Dynamic Cache Monitor enterprise application that displays statistics and contents of the dynamic cache. The monitor can be accessed via a Web browser accessing the following URL:

https://<hostname>:8002/cachemonitor

This application is provided as an installable Enterprise Archive (EAR) file and can be installed in a server that has dynamic cache enabled. With this application, you can monitor caching interactively and invalidate pages.

In summary, almost everything can be cached if the pages are broken down into smaller fragments. DynaCache can be viewed as a sophisticated hash table that can increase performance and reduce infrastructure costs. Among its many features include the ability to off load caching from memory to disk, full page and fragment caching, invalidation support (either manual using cache monitor, time-out based, event driven, WAS API, or invalidation command) and replication across servers and Edge of Network caching support. DynaCache is configured through a policy-based XML file called cachespec.xml. Some factors to consider on deciding what to cache include reusability, invalidation and variations of the JSP fragments. Finally, for best performance, caching should be placed as close to the user as possible.

34Keeping Commerce Applications Updated WebSphere Commerce 5.1 to 5.6 Migration Guide