WebSphere

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WAS redirects here. For other meanings, see WAS (disambiguation).
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WebSphere refers to a brand of IBM software products, although the term also popularly refers to one specific product: WebSphere Application Server (WAS). WebSphere helped define the middleware software category and is designed to set up, operate and integrate e-business applications across multiple computing platforms using web technologies. It includes both the run-time components (like the application server) and the tools to develop applications that will run on WAS.

WebSphere is built using open standards such as the Java 2 Platform, Enterprise Edition (J2EE), XML and Web Services. Multiple IBM labs around the world participate in creating WebSphere run-time products and development tools.

Contents

WAS Versions

IBM has shipped several versions and editions of the application server. In the original beta versions, WebSphere was called Servlet Express.


  • Version 1
    What started it all in June 1998. Really only a servlet engine at that point.


  • Version 2
    Adds JavaBean and CORBA support. Now supports Linux. Comes in two editions:
    • SE (Standard Edition)
    • AE (Advanced Edition)


  • Version 3
    This version of WebSphere was a JDK 1.2, J2EE 1.0 version. IBM provided many enhancements to the basic J2EE 1.0 spec. Support for AS/400 and OS/390 is added.
    • SE (Standard Edition)
    • AE (Advanced Edition)
    • EE (Enterprise Edition)


  • Version 3.5
    • SE (Standard Edition)
    • AE (Advanced Edition)
    • EE (Enterprise Edition)


  • Version 4
    This was a J2EE 1.2 certified application server. It inherited the database based configuration model from V3.x for all but the single-server edition, which already used an XML datastore.
    • AE (Advanced Edition)
    • AEs
      Single-server edition that was not able to run in a cluster configuration.
    • AEd (Developer Edition)
      Functionally equivalent to AEs, but only for non-production development use.
    • EE (Enterprise Edition)


  • Version 5
    This was a J2EE 1.3 certified application server. It was a major rewrite of the V3, V4 code base. The database based configuration repository was replaced with a replication file based configuration repository. A server called the deployment manager had the master copy of the cell configuration and nodes had the file they needed for the node copied from this master server when ever they changed. It also included a cut down version of MQ 5.3 called the embedded JMS server.
    • Express
    Replaces the Standard Edition. Express now becomes the term to indicate SMB-oriented offerings from IBM, across all it software brands.
    • Base
    • Network Deployment
      This version supports deployment of a cell configuration with cluster and J2EE failover support. It now also includes Edge Components, previously known as Edge Server. This provides a proxy server, load balancing and content-based routing.
    • Enterprise Edition
      This version added a workflow engine, called the Process Choreographer, for the first time but does not use the BPEL standard. It also added the first fully supported application threading model called WebSphere Async Beans.


  • Version 5.1
    The main change from V5.0 was a JDK upgrade to 1.4.2 and use of the Jython language for wsadmin scripting support instead of only supporting Jacl.
    • Express
    • Base
    • Network Deployment
    • WebSphere Business Integration Server Foundation V5.1
      This is the follow on product to WebSphere Application Server Enterprise Edition V5.0. The workflow engine was updated to support BPEL rather than the proprietary FDML format used in V5.0. The product was also repriced.
    • WebSphere eXtended Deployment (XD)
      For more information please reference the #WebSphere eXtended Deployment section below.


  • Version 6
    This version was released in December 2004. It is a J2EE 1.4 compliant application server.
    • Express
      Many programming model extensions previously found in WebSphere Application Server V5.0 Enterprise Edition were moved out of enterprise and into Express and Base. These APIs included application profile, startup beans, the scheduler and async beans.
      The JMS engine was rewritten in 100% Java and its functionality greatly enhanced.
    • Base
    • Network Deployment
      The clustering was rewritten to use the high availability manager. This manages all singletons in the WebSphere environment and can provide hot recovery for those singletons.
      WebSphere was modified so that a shared file system can be used to store transaction logs and this meant that any cluster member with that shared file system mounted can hot recover in doubt XA transactions with no external HA software.
      The deployment manager's role was eliminated from all clustering runtime operations. It's only required for centralized JMX admin and config changes.
      Now supports running mixed version cells (V4 to V6) in production.
    • eXtended Deployment
      This added the ObjectGrid component which is a standalone distributed cache that can be used with WebSphere (any version with a 1.4 JDK) or with any J2SE 1.4 runtime.

WebSphere eXtended Deployment

WebSphere Application Server V5.1 Extended Deployment Edition (WebSphere XD) was initially released in October 2004 as an addon for WebSphere 5.1.1 or WebSphere WBISF 5.1 (integration offering). XD provides advanced features for both administrators who manage multiple J2EE based applications and developers building advanced applications that require asymmetric clustering techniques.

Administrator benefits (ie load balancing)

Many businesses run multiple server farms but wish to consolidate them into a single smaller server farm. This is because most server farms are underutilizied or over provisioned. The boxes are typically running at 10% load which is quite costly and is not flexible. For example, one server farm goes hot and maxes out while the farm in the next room is still basically idle at 10%. XD allows administrator to define a single cluster (a node group) then monitor the workload and dynamically decide which boxes in the node group should host which application in order to meet these goals. If application A has a current response time of 1.5 seconds, XD will move resources away from applications B and C to increase the power dedicated to A and decrease its response time. XD can also predict that A will likely exceed its response time in 10 minutes based on a trend and react in anticipation of the event. This greatly simplifies the life of an administrator and allows the machines to be more efficiently used than a conventional multiple, independent farm of farms approach. XD also offers options to generate various email alerts when conditions are exceeded, it can restart servers when they appear to have a memory leak or after X requests.

Developer benefits

WebSphere Partition Facility

Traditional J2EE applications work well for a large class of applications. The class can broadly be categorized as applications that run in a stateless symmetric cluster in front of a database:

  • all the cluster members can perform any task at any time.
  • the application is stateless.
  • the application is modal which means it only performs work synchronously in response to a client request which can be received using HTTP/IIOP or JMS.

There are other applications that do not work well in such an environment, for example, an electronic trading system in a bank. Such applications typically use tricks that can greatly improve performance such as partitioning, multi-threading and write through caching. These are applications that can exploit asymmetric clustering. An asymmetric cluster is practically the opposite of a symmetric cluster:

  • Applications can declare named partitions at any point while it is running partitions are highly available, are mobile within the cluster and usually only run on a single cluster member at a time.
  • Incoming work for a partition is routed to the cluster member hosting the partition.
  • The application is amodal. Partitions have a lifecycle of their own and can start background threads/alarms as well as respond to incoming events whether they are IIOP/HTTP or JMS/foreign messages.

WebSphere XD offers a new set of APIs called the WebSphere Partition Facility (WPF). These APIs allow applications that require an asymmetric cluster to be deployed on a J2EE server.

ObjectGrid

The ObjectGrid is the first piece of the IBM distributed caching framework. V6 of XD shipped with support for local Java Object caching as well as peer to peer caching with asynchronous data push/invalidation. It is designed as a small footprint, no install customer extensible framework for caching objects. All aspects of the core framework have plugin points. This allows customers to add function as well as allow IBM to extend it in future product levels. It's designed to run independant of WebSphere. This doesn't mean it doesn't integrate with WebSphere 6.0 XD, it does. But, it will also work on older versions of the application server, tomcat servers, and competitive application servers. It's intended to compete against the other distributed cache products on the market. It currently requires only a 1.4 level JDK from any vendor. Version 2 of the ObjectGrid is currently under development for shipping in XD 6.0.1. It will add significant function to the component as well as widen JDK level support. The intent is to allow customers to build large grids of JVMs in to which they can connect applications and store objects at various qualities of service. The grid is being designed to scale to 1000s of JVMs and hold a large quantity of data.

See also

External links

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