Normally an application server is configured for servant region affinity, and HTTP session objects reside in one or two servant regions. If you want HTTP requests more evenly distributed to the servant regions in your configuration, you can configure an application server to use the workload management (WLM) even distribution of HTTP requests function. When an application server uses the WLM even distribution function, HTTP requests, for which affinity has not yet been established, are evenly distributed, in a round-robin manner, to all of the servant regions in your configuration.
Before you begin
Your application server should be running on a z/OS system that is at Version 1.4 or later. Because you are distributing HTTP requests among multiple servant regions in this task, you should also have multiple servant regions enabled to use this function. See Enabling multiple servant regions for more information.Why and when to perform this task
Use this task if your application server is experiencing problems with the default workload distribution strategy. The default workload distribution strategy uses a hot servant region for running requests that create HTTP session objects. Consider configuring WebSphere Application Server and the z/OS Workload Manager to distribute HTTP requests, for which affinity has not been established:Steps for this task
TransClassMap *:8080 /Dynacache1Web1/Servlet1 TCLASS1 TCLASS2 TCLASS3
TransClassMap *:8080 /Dynacache1Web1/Servlet1 TCLASS1You also must update the z/OS workload manager policy to remove the extra service classes that were only necessary to get WebSphere Application Server managed round robin support. Following is an example of removing the extra service classes:
Subsystem-Type Xref Notes Options Help -------------------------------------------------------------------------- Modify Rules for the Subsystem Type Row 9 to 16 of 16 Command ===> ____________________________________________ SCROLL ===> CSR Subsystem Type . : CB Fold qualifier names? Y (Y or N) Description . . . Component Broker requests Action codes: A=After C=Copy M=Move I=Insert rule B=Before D=Delete row R=Repeat IS=Insert Sub-rule More ===> --------Qualifier-------- -------Class-------- Action Type Name Start Service Report DEFAULTS: AZAMS1 RBBDEFLT ____ 1 CN AZSR01 ___ AZAMS1 RAZAMS1 ____ 2 TC TCLASS1 ___ AZAMS1 RAZAMS1 _d__ 2 TC TCLASS2 ___ AZAMS2 RAZAMS1 _d__ 2 TC TCLASS3 ___ AZAMS3 RAZAMS1 ____ 1 CN AZSR02 ___ AZAMS2 RAZAMS2 ____ 1 CN AZSR02 ___ AZAMS3 RAZAMS3 ****************************** BOTTOM OF DATA ******************************
Results
The application server uses the WLM even distribution of HTTP requests function to handle its workload instead of showing affinity to a certain servant region.What to do next
See Detecting and handling problems with run-time components to handle problems with server clusters and workloads.