WAS Topology: Front Ends


Front end functionality

Functionality Web server plug-in used with either IHS or Apache Web server plug-in used with either IHS or Apache with Intelligent Management DataPower Service Gateway ODR DMZ Secure Proxy Server for IBM WAS -OR- WAS proxy server
Session affinity Yes Yes Yes18, Yes1, 2 Yes (for DMZ proxy only) 1, 2
DMZ ready Yes Yes Yes No Yes (for DMZ proxy only)
Custom advisors are supported No No Yes No No
Service Level Agreement (SLA) No No Yes Yes No
SIP proxy No No No Yes Yes
ESI dynamic Caching Yes Yes No Yes 3 Yes 3
Managed from the administrative console Yes Yes Partial19 Yes Yes4
Stream caching (large response caching) Yes Yes No Yes Yes
Dynamically receive management events5 No No Yes18 Yes6 Yes6
Multi cells routing No No Yes20 Yes8 Yes8
Performance monitoring Yes9 Yes9 Yes Yes10 Yes10
Load Balancing (weighted round-robin) Yes11 Yes11 Yes Yes11 Yes11
Route rules are configurable No12 No12 Yes Yes Yes
Interoperability with WLM Yes13 Yes13 Yes18 Yes Yes
Web service affinity and failover (WS Addressing) No No Yes18 Yes Yes
Rule expression and custom routing No Yes Yes21 Yes15 Yes15
Generic server cluster (GSC) affinity and failover No No Yes Yes16 Yes16
Per Request Trace No Yes Yes Yes No
Weighted Least Outstanding Request (WLOR) No Yes Yes Yes No
Health Policy Support No Yes Yes Yes No

Table notes:

  1. Session affinity is supported for WAS managed resources. However, some session management custom properties, such as HttpSessionCloneId, are not supported.

  2. For generic server routing, where the resources are not WAS managed resources, active session affinity and passive session affinity need to be configured under generic server routing action.

  3. WAS proxy servers and DMZ Secure Proxy Servers for IBM WAS do not support fragment caching. Only whole page caching, and the ESI invalidation servlet are supported.

  4. Secure proxy profile on a DMZ installation can only be managed or an administrative agent. Configuration-only secure proxy profile can be managed through scripting or the administrative agent console. If we use an administrative agent console, you must register a proxy profile with the administrative agent.

  5. As performed by ODR in a WebSphere Extended Deployment environment.

  6. Static routing needs to be turned off and core group bridge tunneling needs to be enabled for both the DMZ Secure Proxy Server for IBM WAS, and the core group bridge interface for the WAS Network Deployment cells.

  7. Requires core group bridge setup between the proxy cell and other cells.

  8. Static routing needs to be turned off and core group bridge tunneling needs to be enabled for both the DMZ Secure Proxy Server for IBM WAS, and the core group bridge interface for the WAS Network Deployment cells.

  9. The web server plug-in statistics are obtained from request metrics.

  10. WAS proxy server statistics and DMZ Secure Proxy Server for IBM WAS statistics can be retrieved from Tivoli performance viewer, ARM, and performance mBeans.

  11. Random Load balancing is supported in addition to weighted round robin.

  12. Web server plug-in can only do static routing.

  13. A web server plug-in indirectly has interoperability with WLM through the exchange of dynamic workload manager (DWLM) Partition Tables between the web server plug-in and WAS. The plug-in uses these tables for dynamic routing and failover scenarios within a cluster.

  14. The proxy server uses the WAS WLM even if the proxy server is running on a z/OS operating system.

  15. The DataPower appliance manager provides faster web service affinity and failover service than Java proxy provides.

  16. Rule expression and custom routing allows administrators to override default WAS routing behavior. For example, you might not want requests forwarded to server1 in a cluster between 11:00 PM and 12:00 PM because you regularly apply maintenance to that server during that time interval.

  17. Proxy server supports load balancing and failover for generic server clusters with passive and/or active affinity.

  18. Requires WebSphere DataPower AO module.

  19. Configuration with regards to cluster members, weights, session affinity, and application edition support is performed via the WAS ISC Console, but it is retrieved and acted upon by WebSphere DataPower.

  20. Multi cell routing is based on policy and rule configuration within DataPower. This is independent of the WAS configuration.

  21. Content-based routing is provided via WebSphere DataPower configuration policy and stylesheets.

Functionality Web server plug-in used with either IHS or Apache Server with or without Intelligent Management DataPower Service Gateway ODR DMZ Secure Proxy Server for IBM WAS -OR- WAS proxy server
Common Gateway Interface (CGI) Yes No No No
Request URI rewriting Yes Yes No No
Efficient static file serving Yes No Basic1 Basic1
Compression Yes Yes Yes Yes
Response filtering Yes Yes Yes2 Yes2
SSL termination Yes Yes Yes Yes
Cryptographic Accelerator3 Yes Yes Yes4 Yes4
FIPS Yes Yes Yes Yes
Third-party/customer-written plug-ins Yes Yes8 No No
Logging Yes Yes Yes5 Yes5
Custom logging Yes Yes Yes No
Disk caching Yes No Yes Yes
Asynchronous request handling none or partial6 Yes Yes7 Yes7

Table notes:

  1. WAS proxy servers support basic static file serving.

  2. WAS proxy servers support HTML link rewriting.

  3. This functionality only applies to Cryptographic Accelerators that WAS supports.
  4. The support is provided by IBM JDK/JCE.
  5. Only NCSA common format is supported.
  6. The connection between a web server plug-in and an application server is synchronous and consumes a thread while reading/writing or waiting for data.
  7. Proxy server is optimized to handle AJAX long polling requests under large scale deployments.
  8. Sophisticated rules and custom processing can be achieved using Extensible Stylesheet Language Transformations (XSLT).


Related tasks

Proxy server setup
  • Configure a DMZ Secure Proxy Server for IBM WAS using the administrative console