In an effort to maintain a healthy operating environment, one thing to be cognizant of is shutting down agents that are no longer being used in your environment. In the errors.txt file of you Workload Automation DE Manager, you will see messages indicating "Key not available for node...." The full context of this message will be provided in the Background section of this document.
Customer's may see messages similar to:
20170426 09:30:59.355 [essential] [ERROR] DM.InputProcessor_1: Exception: Key not available for node LNXWASUPPORT.
com.cybermation.espresso.library.crypto.CryptoException: Key not available for node LNXWASUPPORT.
This message is indicative of an agent spoofing the Scheduling Manager. That is to say that the Agent is still aware of the Manager and is trying to establish a connection with it. However, the Manager does not have a valid agent definition any longer for the agent because someone either removed it or it was never defined.
To resolve this issue, you will need to do one of two things: