Load Balancing Identifier  

The Load Balancing Identifier used for Load balancing to Web AS Java instances has the following syntax.

saplb_<group_id>=(<instance_id>)[<node_id>]

 

The cookie is set on path=”/” and domain=<host>.

The same syntax applies if the identifier is used via url rewriting.

 

The <node_id>applies only to the J2EE Engine where session stickyness on a process (JVM) level is required. The <group_id> uniquely identifies a set of instances. If there are no special group definitions then the special group identifier ‘*’ is used. This will be the case for a default installation.

The SAP Web Dispatcher checks for path prefix match and thereby determines group name (see Determining the Server Group). This allows to obtain <instance_id> from the set of dispatch cookies or to do initial load balancing for the group. The Java dispatcher receives the request and also checks for the group. The Java dispatcher then reads <node_id> from the appropriate dispatch cookie or performs initial dispatch on his local nodes.