WebSphere Extended Deployment, Version 6.0.x
             Operating Systems: AIX, HP-UX, Linux, Solaris, Windows, z/OS


Configuring passive HTTP session affinity in the on demand router

In most cases, the on demand router (ODR) does not require configuration to support HTTP session affinity. However, some special cases exist where you must configure the ODR to learn about backup servers that the back-end servers might be setting on the session affinity cookie.

Before you begin

Create the ODR. The servers in your configuration must be in a generic server cluster or a dynamic cluster. Do not configure the passive HTTP session affinity on static clusters.

About this task

Passive HTTP session affinity is used in the following situations:

Procedure

  1. Create and modify the session affinity descriptor. In the administrative console, click Servers > Dynamic clusters or Generic server clusters > cluster_name> Custom properties > New.
  2. Define the session affinity descriptor properties. Create a custom property to define the session affinity descriptor. Enter the name of the custom property as HttpSessionAffinityPolicyDescriptor. The value must be in the following format:
    <learnCloneIDs>!@#<cookieNames>!@#<urlRewriteNames>!@#<delimiter>
    • <learnCloneIDs>

      Equals true or false. If true is specified, the ODR parses the clone IDs from the Set-Cookie headers in the response as the response flows back to the client. You must set this value to true when you are routing to servers with session cookies that contain the server clone information. If you do not know if the session cookies from the servers contain the server clone information, or you know that the session cookie from the servers does not contain the clone identification, then set the value to false and set the Affinity mode to active-conditional.

    • <cookieNames>

      Specifies a comma-separated list of cookie names that can be used to pass session information.

    • <urlRewriteNames>

      Specifies a comma-separated list of names to search for in the Uniform Resource Locator (URL) for session information.

    • <delimiter>

      Specifies the delimiter that is used by the ODR when extracting clone IDs from the session information.

    • The default value of the HttpSessionAffinityPolicyDescriptor custom property is:
      false!@#WSJSESSIONID,JSESSIONID,SSLJSESSIONID!@#jsessionid!@#:
      The false value indicates that clone IDs are learned directly from the servers, not by parsing responses. The WSJSESSIONID,JSESSIONID,SSLJSESSIONID value causes the ODR to look for three different cookie names to find session information, and then jsessionid in the URL. When extracting clone IDs from the session information, the : delimiter character is used.

Results

When the ODR processes a request, it obtains the session affinity descriptor policy that is configured for the cluster to which the server belongs. The method in which the server clone identification is obtained depends on the property values of the policy attributes.




Related tasks
Creating ODRs
Routing requests to external nodes with generic server clusters
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Last updated: Nov 30, 2007 3:58:31 PM EST
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