18.3.2.5 JmxMBeanContextFactory

JmxMBeanContextFactory implements the com.sun.management.snmp.agent.SnmpUserDataFactory interface. The userData allocated by this factory is a java.util.Map that serves as a request-contextual cache. When the MIB instrumentation needs to access a piece of data, it proceeds as follows.

• Firstly, it looks for it in the request-contextual cache, namely, in the userData.

• If the required data is not found,the MIB instrumentation computes its value, puts it in the request-contextual cache, and then returns it.

This mechanism ensures the coherency of the data returned in the response. Once a piece of data has been loaded into the request-contextual cache, it is consistently reused for the whole duration of the request. This makes sure that the same snapshot is always used during the request, even if the underlying managed object constantly changes its value.