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3.6 Using NWBC with a Load Balancer Locate this document in the navigation structure

 

If a load balancer is available within the network, it can be used directly with NWBC. Instead of configuring a direct URL on a specific application server, change the URL that NWBC is configured to use to that of the load balancer. On startup, NWBC triggers a first HTTP request to the load balancer, which then redirects to an application server. For the duration of the NWBC session, it only communicates with this specific application server. All applications that are started run on the assigned application server. (This is similar to a typical SAP GUI session that stays on the same assigned application server and starts all new windows on the same server.)

In NWBC for Desktop, navigation data is cached on an ABAP system (AS ABAP), and not on a specific application server. Therefore, if the load balancer assigns a different application server the next time NWBC for Desktop is started, it does not invalidate the cached data.

Recommendation Recommendation

It is highly recommended to use SAP Web Dispatcher as a load balancer, since it also contains key information about HTTP traffic, which can be used to route all subsequent HTTP requests more effectively onto the same application server.

End of the recommendation.

Load balancer example (Load balancer example)

By default, transaction NWBC starts NWBC for HTML or the ~launch page against the same AS ABAP application server. For more information, see 4.9 Transaction NWBC and 4.8 ~launch Page. However, transaction NWBC also considers all information available about an external Web Dispatcher, or message server used as load balancer, if configured within the HTTPURLLOC table. Within the HTTPURLLOC table, configure an entry for application = /NWBC/* to influence the URL generation of NWBC. With such an entry configured, the startup URL is changed to directly reference the configured load balancer.

Example entry in table HTTPURLLOC (Example entry in table HTTPURLLOC)

Note Note

You can also use load balancing settings of the SAP GUI if you enter the corresponding system name exactly as it is in the SAP Logon in SAP Logon System. Therefore, for each newly created session (some sessions are reused), you are routed to another server. For more information, see 3.4.1 Configuring Connections. In the example below, a SAP GUI session is started (the same SAP GUI session as if the corresponding entry in the SAP Logon is double-clicked, and the same load balancing settings are used).

End of the note.

SAP GUI Logon Description and SAP Logon (SAP GUI Logon Description and SAP Logon)

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