We are in an air-gapped environment connection to Dynatrace Mission Control is ONLY open during patching or software upgrade.
Due to whatever reasons. Security folks is going to limit the timing to the connection to Dynatrace Mission Control.
Correct me if I am wrong. Assuming we are on a n-1 version. Security folks open the connection at UTC 00:00
At about 00:15 . We would get the new email product update for "Dynatrace Managed Cluster 1.2XX" ?
Assuming we have 5 node cluster and each node takes 30 mins to upgrade.
So the new email update will be 00:15 + 2hr 30mins + 15 mins?
Approximately 03:00 . We would get the next email product update for the installer of the rest of the components?
With that we should be able to close out the connection?
Or is there an option for us to trigger the 2nd email for the installer of the rest of the components?
From experience with my customers who use the Managed version, I know that those estimated download and update times for the cluster you indicated do not always match reality. The download time and the update process itself are affected by many aspects (DT server load, network, size of the update, etc). I have experienced such slowdowns on my client environments - quite regularly.
I would recommend creating a service window with network access for a minimum of 3h-4h).
There is also a version of the Dynatrace Manage Offline licence that allows you to completely disconnect your DT cluster from the external network and then you get links to update packages that you download and decide when to upload them. Unfortunately, it has other caveats such as cyclical verification of licence utilisation by those authorised by Dynatrace.