Licensing on License Server Cluster (A/P)
A LICENSE-SVR license must be installed on at least one node in the cluster that will work in a cluster node fail-over scenario.
If any node in the cluster has a LICENSE-SVR license, the entire cluster shifts to LICENSE-SVR mode.
The active node should be able to lease all of the licenses installed on both nodes.
Let us say, if node-1 has LICENSE-SVR license and node-2 does not. If node-1 goes down, then node-2 gets to lease all the licenses, till the 20-day grace period. After 20-days, node-2 can lease only the licenses installed on it.
Cluster Splits | | | | | | | | |
|---|---|---|---|---|---|---|---|---|
Server License Installed on | Both Nodes | | | | Only Node A | | | |
| Within Grace Period | | Beyond Grace Period | | Within Grace Period | | Beyond Grace Period | |
Features | User Traffic | License Leasing | User Traffic | License Leasing | User Traffic | License Leasing | User Traffic | License Leasing |
Behavior for Node A | No | Yes | No | Yes | No | Yes | No | Yes |
Behavior for Node B | No | Yes | No | Yes | No | Yes | No | Yes |
Key Points About Licenses in a Cluster
- Within a cluster, user licenses are shared among all nodes.
- Licenses are additive in cluster. The total user count would be sum of all nodes in the cluster.
- Install licenses equally on each node in the cluster.
- Careful consideration should be taken when removing a node from a cluster. Removing a node will impact the total number of users.
Reason for Installing Licenses Equally in a Cluster
The reason is to prevent loss of user count during node failure. A node can only borrow up to two times (2x) the total number of licenses installed on the device locally for a 10-day grace period. After 10-day period, the user count will revert to the total number of licenses installed locally.
If the licenses are evenly distributed in the cluster, the user count will remain the same regardless which node fails. If the licenses are unevenly distributed in the cluster, the user count will be different depending on which node fails (Refer to Scenario A and B for examples).
For example:
- Node_108 = 35 user license
- Node_109 = 100 user license
When clustered, the total number of users is 135 (35 + 100 = 135).
Scenario A:
If Node_109 goes down, the total number of licenses would be 70 users. ( 35 X 2 = 70).
The maximum number of users will be 70 for the 10-day grace period. After the grace period expires, the user count will drop to 35 users.
Scenario B:
If Node_108 goes down, the total number of licenses would be 135 users (100 + 35 = 135).
The maximum number of users will be 135 user for the 10-day grace period. After the grace period expires, the user count will drop to 100 users.
Why is the calculation different?
In this scenario, the device can only borrow up to the total number of user licenses in the cluster. This means instead of (100 x 2 = 200), it will only (100 + 35 = 135).
How license count is impacted when removing a node from a cluster?
If a node is removed from an existing cluster, this will decrease the total user count. For example:
- Node A = 100
- Node B = 100
The total user count would be 200 (100 + 100). If Node B is removed from the cluster, this will drop the total number to 100 as Node B is no longer part of the cluster.