Configuring Update Groups 
In an SAP system, automatic load distribution (also known as dispatching) takes place even with asynchronous updates. The default is for this load distribution is to include all available update work processes . This global dispatching is however not always required.
To deal with this, application servers can be divided up into groups, and update requests processed within the group only. Update dispatching then takes place within the groups.
Dispatching cannot take place across more than one group.
Note
Dispatching is activated by setting profile parameter rdisp/vb_dispatching = 1. If this parameter is set to 0, all update requests are sent to the server specified in profile parameter rdisp/vbname.
The update groups have the following properties:
All application servers that are not assigned to any group represent the default group.
An application server can belong to only one group.
Every group has to contain at least one update server.
Choose
(Administration of the Update System).
Choose the Server Groups tab.
Here you can create, change, and delete update groups.
You can assign a server to an existing group as follows:
Click on the group
Choose Display Servers. The list at the bottom left of the screen is called <group name>
From the Servers Not Assigned list (bottom right), choose the servers you want to include in the group, and use the buttons with the black arrows to include or delete servers from the group.
Use the
(Overview) button (top right) to go to the overview of the configured update groups.