Logon load balancing increases the efficiency of various workgroups that have been defined, in terms of performance and system resource consumption, by distributing users across available application servers based on requirements for workgroup service and load sensitivity.

In a system landscape where there are several application server instances, specific servers are best assigned to specific application workgroups, whereby the available resources and buffers of that server are set specifically to the application and not shared with other applications. This is illustrated below:

With logon load balancing and servers assigned to specific applications:

With logon load balancing and shared, or homogeneous, server properties across logon groups:

With logon load balancing and servers available to all applications

With only two servers with logon load balancing and servers assigned to specific groups:

Each SAP application has different resource requirements. Certain applications may therefore require more servers and logon groups. For example, you should assign separate servers for the R/3 application component PP.

In general, each logon group should have two servers. If one server is not available, users are automatically connected to the second server. Servers can be added or removed while the R/3 System is running.

If it is not practical for you to assign separate servers to closely integrated R/3 applications such as the application components SD-MM and FI-CO, you should assign common logon groups to these applications.