The VoltDB Enterprise Edition is licensed software. Once the license expires, you will not be able to restart your database cluster without a new license. So it is a good idea to update the license before it expires to avoid any interruption to your service.
You can use the voltadmin show license command to see information about your current license, including the expiration date. You can then use the voltadmin license command to replace the current license with a new license file.
$ voltadmin license INFO: The license is updated successfully. . . .
When you issue the show license command, VoltDB verifies that the license file is valid and the terms of the license are sufficient to support the current database configuration. Once verified, the license is applied to all nodes of the cluster and information about the new license is displayed.
If a node fails to get updated (for example, if a node fails during the license update), you will need to update that node independently when bringing it back into the cluster. You can do this by including the new license file on the command line when you restart the node. For example:
$ voltdb start -D ~/mydb --license license.xml Initializing VoltDB...