One of the new features in the 2.4.0 release is a new presence implementation.
Presence is what determines whether or not agents are shown as lost or down in juju status.
In the 2.4.0 release, the new presence implementation runs in parallel with the old implementation and there is a runtime controller feature flag for turning on and off the new behaviour.
To enable the new presence code path, run the following:
juju controller-config features=[new-presence]
To disable the new presence and go back to the default way, run the following:
juju controller-config features=[]
The primary user facing difference between the old way and the new way is the immediacy of reporting. Presence is determined by an agent having an active API connection to the controller.
There is a theoretical potential speed improvement to juju status, but I have not been able to confirm this on small models. As we get larger models upgraded to 2.4.0 Iād like to get some timing differences.