To optimize performance, an SNMP agent caches the credential maps that correlate WebLogic Server users with SNMP credentials. To make sure that the cache contains the latest set of SNMP credentials, an agent periodically invalidates its cache. (For information about the option that configures the frequency with which an agent invalidates its cache, see the Credential Cache Invalidation Interval option in Configuration Options.) After the cache is invalidated, the next time the agent requests credentials, it regenerates its cache.
Note that making a change to the credential map does not automatically update the cache for SNMP agents. Instead, the cache is updated only after it has been invalidated. For example, if you update a privacy password in an existing entry in the SNMP credential map, SNMP agents are not aware of the new password until their caches are invalidated and regenerated. An SNMP user with the old security password can still use the agents to access WebLogic Server data until the cache is invalidated.
After you modify a credential map, you can either wait for each SNMP agent to invalidate its cache, or you can invalidate it immediately.