OpenEdge Getting Started: Installation and Configuration - Product ...

Understanding load balancing
Understanding load balancing
Load balancing is a feature that allows client connection requests to be distributed
among multiple Unified Broker instances that support the same Application Service.
Load balancing is a NameServer option that comes installed with some products (for
example, the WebSpeed Enterprise Transaction Server) or that you must install as an
option with others (for example, the AppServer). If you have load balancing with your
product, the NameServer assigns client connections to the appropriate Unified Broker
instances based on weight factors that you specify.
If the weight factor that you specify for each Unified Broker instance is appropriate in
relation to the others, the effect is to assign more connections to broker instances with
greater resources, and thus to balance the connection load among all the instances.
You can set the load-balancing weight factor for each Unified Broker instance in
OpenEdge Management or OpenEdge Explorer or by editing the priorityWeight
property in the ubroker.properties file.
Percentage weight factors
Properly specified, weight factors give some sense of the amount of work that an
individual Unified Broker instance can handle. For example, Table 130 shows the effect
of weight factors specified for three Unified Broker instances registered to support the
same Application Service.
Table 130: Weight factors based on percentage
Unified Broker name Weight factor
AS1 20 20
AS2 20 20
AS3 60 60
Percent of time
selected
The selection algorithm used by the NameServer guarantees that AS1 and AS2 are
each selected 20% of the time and AS3 is selected 60% of the time. Thus, if the sum
of weight factors for all Unified Broker instances that support the same application adds
up to 100, each weight factor specifies the exact percentage of time that the
NameServer selects the given Unified Broker instance over time.
OpenEdge Getting Started: Installation and Configuration 491