In large DSM environments with several Business Logic Servers (BLS), users are able to control the load balancing between the individual BLSs. The purpose of load balancing is to take the load off the central BLS and also to distribute the requests of the Web Services between the available servers or to direct the requests to specific servers. Also, you can provide additional BLSs as 'stand by' servers which will take over communication when another BLS fails.
There are two ways of configuring the system to achieve the optimum coordination:
- You can define an individual load balancing factor for every BLS , thus allowing you to control the communication between the clients and Relay Proxies on the one side and the BLSs provided in the environment on the other side (ICDB section Shared Infrastructure).
- You can define a list for the DSMC containing the associated Business Logic Servers (ICDB section DSM Console).
In general, load balancing is always active in a BLS group and can be customized accordingly by changing the load balancing factor (values 0 to 100, default setting 100) . You can customize the factor if you have more than 2 Business Logic Servers (BLS) in your environment; however, we recommend customizing the factor only if you have more than 3 BLS .
The default load balancing behavior is that components always connect to the Business Logic Servers unless the requesting component has its individual setting or unless the requests have to be redirected because of BLS failures.
External Load Balancer
Load balancing may also be achieved by employing an external load balancer. For this, you must enter a Load Balancing URL per site in the ICDB under URL for connections to Management Points (BLS). To perform a client synchronization, the managed clients log on to the specified address and get assigned to their respective BLS.
You can also achieve load balancing between BLS and database by combining several database servers in a database cluster. This procedure must be independent of the DSM environment and according to the specifications of the respective database. At the moment, DSM only supports Microsoft SQL.