Product Documentation

Expected behaviors when issues arise

May 24, 2018

Following are the expected behaviors of the license servers and NetScaler instances when they experience the issues described:

License Server stops responding

Warning message (syslog): The license Server is not responding. NetScaler will continue to operate with the current capacity for 30 days. After 30 days, if the connectivity to the license server is not restored, the NetScaler will loses its current capacity and stops processing traffic.

If the license server stops responding, the NetScaler instance enters the Grace Period until connectivity is restored.

NetScaler pooled-capacity enabled instance stops responding

If the NetScaler pooled-capacity enabled instance stops responding and the license server is in a healthy state, the license server checks in all the NetScaler instance’s licenses after 10 minutes. When the instance reboots, it sends a request to check-out all the licenses from the licensing server.

Both license server and NetScaler pooled-capacity enabled instance stop responding

If both the license server and the NetScaler pooled-capacity enabled instance restarts and reestablishes the connection, the license server checks-in all its licenses after 10 minutes, and the NetScaler pooled capacity enabled instances automatically check-out the licenses after the reboot is completed.

The NetScaler pooled-capacity enabled instance shuts down gracefully

During a graceful shutdown, you can choose to check the licenses in or keep the licenses that were allocated before the graceful shutdown. If you choose to check the licenses in, the NetScaler pooled-capacity enabled instance is unlicensed after the it restarts. If you choose to keep the licenses, they are checked in to the licensing server when the instance shuts down. After the instance restarts, it reestablishes the connection with the licensing server and checks out the licenses as specified in the saved configuration.


If system reboots and the check-out fails due no capacity available in the pool, the NetScaler will check the inventory of NetScaler MAS pool licenses and will check-out any available capacity. An SNMP alarm is raised to notify this condition to the user if NetScaler is not running with full capacity as per configuration. If no capacity is available in the bandwidth pool, the pool capacity enabled instance will become unlicensed.

Network loses connectivity

Error message (syslog): License Server is not responding.

If the license server and NetScaler pooled-capacity enabled instances are in healthy states but network connectivity is lost, the instances continue to operate with their current capacity for 30 days. After 30 days, if the connectivity to the license server is not restored, the instances lose their capacity and stop processing traffic, and the license server checks-in all its licenses. After the license server reestablishes connectivity with the NetScaler instances, the instances check the licenses out again.