1.0 Understanding the Null Service and Loopback Service Drivers

NetIQ Identity Manager includes two utility drivers, Null Service and Loopback Service, whose purpose is to implement custom behavior through policies established on the drivers’ Subscriber and Publisher channels. Like other service drivers such as Entitlement and Workflow, the Null Service and Loopback Service drivers do not connect to external applications or systems.

The Null Service driver performs any tasks that are implemented through policies on the Subscriber channel. The Publisher channel is not used; the driver does not connect the Subscriber channel to the Publisher channel, but rather acts as a sink for most operations, simulates doing something with operations, and then returns success. Typical uses for the Null Service driver include the following:

The Null Service driver should be sufficient for the majority of the tasks you want to perform. However, if you need to process policies on both the Subscriber and Publisher channels, you can use the Loopback Service driver instead. The only difference between the two drivers is that the Loopback Service driver’s Subscriber channel connects to the Publisher channel so that events can also be processed on the Publisher channel.