OracleAS Web Cache

Delevring a content rich site always involves a tradeoff with performace.Oracle AS Web Cache aims to significantlly reduce this tradeoff.

The aim of my current post is give a brief introduction into the faetaures and capabalities of OracleAS Web Cache.

OracleAS Web Cache improves performance of complex applications. Web caching moves frequently used content closer to the user, reducing page building tasks from the application server therby decreasing page load times.

Another feature of OracleAS Web Cache is that it provieds for caching of both static and dynamic web pages allowing scaling of applictions that are planned to be deployed.The dynamic content caching is achived as OracleAS Web Cache employes an advanced validation machanisam to maintain consistency with origin data sources like file systems,content management tools,content feeds and databases.This is further achived as Oracle As Web Cache supports ESI standards. ESI stands for Eege Side Includes which is an open specification for a simple markup language that enables dynamic page fragmentation, caching, and assembly. It improves the performance and reduces the cost of dynamic content creation.
More information on ESI can be found at http://www.esi.org/

Additionally OracleAS Web Cache allows HTTP and HTTPS content caching.Also Oracle As Webcache allows session related caching rules (which is maintatining session tracking without compromiosing on the caching) and Multi version cahing rules(Caching multiple versions for the same URL)

To make use of Oracle AS Web Cacheing you must upgarde your Oracle Applications to use Oracle Appliction Applications Server 9.0.2, the latest certified version however is 10gAS.

OracleAs Web Cache acn also be used to implment a reverse proxy in typical DMZ configurations.Wehn a user sends a request to the Web Cache via the load balanceer or DNS server the web cacahe sneds the request to the application server if it cannot find a chached page for the request,however if it does find a cached page the web cache will deliver the same directly to the browser.

You can also implemet Web Cache Clustering by configuring multiple instances of OracleAS Web Cache.These provide for a failover in case one of the Web Cache cluster member fails.The cache cluster members poll the failed Web cache server for its current status until it is reachable again.Apart from failover cache clustering also aloow to cache extra content by disturbuting the cache load across multiple Web Caches.OracleAS Web Cache uses the relative capacity of each cache to automatically distribute ownership of objects among the cache cluster members.

OracleAS Web Cache can also be used to do load balancing for Oracle Applications. It provides for Stateless Load Balancing and Stateful (Session Binding) Load balancing.

You can specify the Web Cache to compress both cachable and non cachable objects,in such a scenerio the web cache will compress the opbeject based on the object type and the browser type.It uses the GZIP algorithm for this purpose.

You can also go through the OracleAS 10g Web Cache FAQ available through metalink.

Due to the extensive deployment of OracleAS Web Cache it is essential for us to secure our Web Cache. Currently OracleAs web Cache security can be implemented using Restricted Adfministration,SSL and SSL Accleration.
Reffer to Securing OracleAS Web Cache for more information.