Concerns and issues relating to all versions of WebSphere Application Server
The dynamic cache engine is the default cache provider for the Dynacache APIs and frameworks. Starting WebSphere Application Server 220.127.116.11 and 18.104.22.168 Dynacache allows WebSphere eXtreme Scale to act as the core caching engine for Dynacache. You can configure the dynamic cache service to use WebSphere eXtreme Scale as your cache provider instead of the default dynamic cache engine. This provides customers the ability to leverage transactional support, improved scalability, high availability and other XTP features without making changes to their existing Dynacache caching code
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. This capability can also be enabled on WAS service packs 22.214.171.124, 126.96.36.199 and 188.8.131.52 via APAR PK85622
2. What is eXtreme Scale
WebSphere eXtreme Scale can operate as an in-memory database processing space, which you can use to provide in-line caching for a database back-end or to serve as a side-cache. In-line caching uses eXtreme Scale as the primary means for interacting with the data. When eXtreme Scale is used as a side-cache, the back-end is used in conjunction with the eXtreme Scale.
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3. Before you begin
Determine whether using WebSphere eXtreme Scale is beneficial to the applications running in your application servers. The WebSphere eXtreme Scale features significantly increase the distributed capabilities of WebSphere Dynacache beyond what is offered by the default dynamic cache engine and data replication service. With WebSphere eXtreme Scale, you can create caches that are truly distributed between multiple servers, rather than just replicated and synchronized between the servers. eXtreme Scale caches are transactional and highly available, ensuring that each server sees the same contents for the dynamic cache service. WebSphere eXtreme Scale offers a higher quality of service for cache replication than DRS. However, these advantages do not mean that the eXtreme Scale dynamic cache provider is the right choice for every application. Use the decision trees and feature comparison matrix provided in the WebSphere eXtreme Scale Version 7.0 Product Overview publication to determine if this technology is beneficial to your applications. This publication is available on the WebSphere eXtreme Scale library page. Determine the appropriate eXtreme Scale topology for your caching deployment by looking at the section on Topology types on http://tinyurl.com/mz2mo7
4. Why eXtreme Scale ?
WebSphere eXtreme Scale (WXS) is the strategic direction for caching with the WebSphere platform. WebSphere session memory to memory replication can also be configured with WebSphere eXtreme Scale. WXS can fulfills all the generic data and session caching needs of your application. Compelling use cases for using Dynacache with eXtreme Scale and the value add Dynacache provides to WXS is listed below:
- If you are currently spending a lot of money on expensive SAN or storage solutions for hosting the Dynacache disk cache then eXtreme Scale can help your applications leverage system memory instead of expensive SANs and offer better performance. All the cache data will be kept in memory in the WebSphere eXtreme Scale servers eliminating the need for a Dynacache disk cache .
- If you are having issues with performance of the Data Replication Service that is used by Dynacache to replicated data, eXtreme Scale can eliminate all those issue by virtue of providing a scalable replicated cache with a configurable number of replicas. Cache capacity can be increased by simply adding more WXS containers at runtime. WXS automatically redistributes the partitions as new containers are added to the grid.
- If you are existing customer of Dynacache that leverages Dynacache APIs and frameworks and want better caching qualities of service and control, using eXtreme Scale will provide the best of both worlds, i.e. excellent Dynacache plugins like servlet caching, webservices, command caching as well as the scalability of a world class in memory replicated cache. Switching from the default Dynacache provider to WXS need just configuration changes via the admin console or wsadmin. There are no changes to the Dynacache programming model.
- Designed and tested to work together. Dynacache and eXtreme Scale combined solution have gone through extensive functional, system, integration and performance testing.
- All runtime monitoring and administration of classic Dynacache with tools like the cache monitor and the Dynacache runtime mbean work when Dynacache runs on top of eXtreme Scale.
The intricate and gory details on HOW TO conifgure Dynacache with eXtreme Scale will follow in subsequent posts ...