The application server battleground continues to heat up. iPlanet has recently announced some major improvements to their product line. Oracle, too, is wrapping up a new release of their Oracle9i Application Server (Oracle9iAS) product with updates to their caching and Java technologies.
While BEA's WebLogic and IBM's WebSphere are often named as the front-runners in the application server race, we're clearly seeing incredible levels of technical advancement across the board in the middleware space. The Java platform is the technology that makes such rapid improvements possible - and the development community is the beneficiary of all of this largesse.
Oracle and Akamai made news recently when they announced that they've collaborated on a new way to improve the scalability of Web sites and applications. The technology is called Edge Side Includes (ESI) and it defines a simplified markup language that identifies Web-page fragments that can be cached on ESI-enabled servers for faster delivery to end users. Dynamically generated Web pages provide a more personalized browsing experience, but the resulting computational overhead can be overwhelming to a site's infrastructure.
ESI promises to address this issue by enabling the assembly of both cached and noncached page fragments at the edge of the network or the edge of the data center. Edge servers don't normally execute business logic, so they can run on less-expensive hardware and provide superior performance.
Oracle and Akamai have pledged to make ESI an open standard and have invited other vendors to join them in submitting proposals to the appropriate standards bodies. To use ESI, developers embed ESI tags in their Web pages or use JESI (Edge Side Includes for Java) to generate ESI syntax automatically from J2EE applications. Web sites and applications that make use of ESI can be deployed on application servers or content delivery networks that are ESI-enabled.
Both Oracle and Akamai will support ESI in their own products, including the upcoming Oracle9ii Application Server and Akamai's EdgeSuite content delivery network. For example, an ESI-enabled J2EE application running on Oracle9iAS will be able to seamlessly take advantage of Akamai's global network of over 10,000 ESI-enabled content delivery servers (as shown in Figure 1).
Figure 1: ESI Deployment Architecture
The J2EE containers in the upcoming Oracle9iiAS are rumored to be extremely lightweight and easy to install, and are expected to include enhanced support for EJB 2.0. The product also includes updates for performance and scalability, with new load-balancing and clustering for Java applications. Oracle hinted that there will also be additional session state replication and cluster failover capabilities, as well as Transparent Application Failover (TAF) and database state management.
Every Oracle9iAS middle-tier server communicates with an Oracle database using a connection pool, which multiplexes clients on a smaller number of connections to the database, improving performance and scalability. Every application writes its long-lived state persistently to a JDBC-enabled database. When the Oracle database is deployed in a cluster configuration and a specific node in the database fails, all state maintained in the database is transparently "failed-over" to another node in the cluster.
When Oracle9iAS is used in combination with the Oracle database, the middle-tier servers have the ability to transparently reroute JDBC connections and database requests to the failed-over node. Depending on how the connections are set up, Oracle9iAS promises to provide configurable degrees of TAF with the database - cold, warm, and hot failover of persistent state.
The new Oracle9iAS release is slated to be available on a broad range of hardware platforms, scaling from low-end uniprocessor machines to high-end SMP clusters, and on all of the major application server o/s platforms, including Solaris, HP-UX, AIX, Tru64, Windows NT, and Linux. Furthermore, the updated performance for J2EE applications promises to provide "cluster" support independently of the hardware platform or OS being used (i.e., its cluster capability doesn't require a specific SMP hardware configuration). This allows J2EE developers and administrators to be able to leverage these features without being tied to any OS/hardware platform.
These exciting new enhancements will undoubtedly "up the ante" in the hotly contested application server market. Watch for this release from Oracle in the near future.
Alan can be reached at: [email protected]