Configure cell affinity in a multi-tiered environment
We can configure the network to contain multiple tiers of on demand routers (ODRs). In multi-tiered environments, configure the ODRs to have unique ODRSESSIONIDs for the different tiers.
We must enable cell affinity and configure the ODRs. For details, read about creating and configuring ODRs and enabling cell affinity.
An example environment for configuring cell affinity might include a cluster of ODRs that distribute load to multiple IBM Portal application servers at the front end of the network, while at the back end there are clusters of ODRs that distribute load to multiple Web content managers.
There are three important configuration requirements for this task:
- Within a tier, any generic server cluster configurations you create for cell affinity must refer only to ODRs within that tier.
- Within a tier, the ODR session identifier cookie name, which is named ODRSESSIONID by default, must be unique for all the other tiers. We must configure this cookie name as a custom property on each ODR within that tier, as described in the procedure in this topic.
- For the highly available (HA) plugin configuration generator, each plugin-cfg.xml configuration must define the ODR session identifier cookie name to use the IBM HTTP Server to configure ODR affinity. To define the ODR session identifier cookie name, define an additional cell-wide custom property associated with the plugin-cfg.xml generation configuration: ODCPluginCfgOdrSessionIdCookie_<configname>=CookieName>. For more information about configuring the HA plug-in configuration generator, read about configuring an ODR to dynamically update the web server plug-in configuration.
- From the console, select Servers > Server types > On demand routers > odr_name.
- Expand On demand router properties.
- Click On demand router settings > Custom properties > New.
- Type odrSessionIdCookieName for the name value.
- Type the new cookie name. For example, ODRSID_TIER1.
- Repeat steps 3 through 5 for every ODR within the tier.
Create ODRs Configure ODRs Enable cell affinity Use generic server clusters with cell affinity Configure an ODR to dynamically update the web server plug-in configuration