FglAM does not shut down due to "Could not obtain a deployment lock" error during upgrade (4227225)

When a monitored database host is shut down, the upgrade of the Agent Manager may hang. Error messages similar to the following may be repeated in the FglAM log

VERBOSE [Quartz[0]-6] com.quest.glue.core.deployment.PackageChangeMonitor - Could not obtain a deployment lock. Will try again in 30,000 ms.
VERBOSE [Quartz[0]-6] com.quest.glue.core.deployment.PackageChangeMonitor - Could not obtain a deployment lock. Will try again in 30,000 ms.
VERBOSE [Quartz[0]-6] com.quest.glue.core.deployment.PackageChangeMonitor - Could not obtain a deployment lock. Will try again in 30,000 ms.
VERBOSE [Quartz[0]-6] com.quest.glue.core.deployment.PackageChangeMonitor - Could not obtain a deployment lock. Will try again in 30,000 ms.
VERBOSE [Quartz[0]-6] com.quest.glue.core.deployment.PackageChangeMonitor - Could not obtain a deployment lock. Will try again in 30,000 ms.
VERBOSE [Quartz[0]-6] com.quest.glue.core.deployment.PackageChangeMonitor - Could not obtain a deployment lock. Will try again in 30,000 ms.
VERBOSE [Quartz[0]-6] com.quest.glue.core.deployment.PackageChangeMonitor - Could not obtain a deployment lock. Will try again in 30,000 ms.

Oracle JDK bug

https://bugs.java.com/view_bug.do?bug_id=8172578

WORKAROUND 1

Fix the disconnection to let the upgrade process after stopping the agent normally.

WORKAROUND 2

This Delete the corresponding Agent that lost the connection from the Agent Status page. The agent can then be added back to the FglAM and the FglAM restarted.