If a license is not already registered for the cluster, when you install X-Pack and start the cluster, it generates a basic license.
If you want to try all of the X-Pack features, you can start a 30-day trial. At the end of the trial period, you can purchase a subscription to keep using the full functionality of the X-Pack components.
When your license expires, X-Pack operates in a degraded mode. For more information, see License Expiration.
You can initiate a trial license only if your cluster has not already activated a trial license for the current major X-Pack version. For example, if you have already activated a trial for v6.0, you cannot start a new trial until v7.0. To check whether you can initiate a trial in your cluster, use the get trial status API.
To start a trial, use the start trial API.
For more information, see X-Pack License Settings.
You can update your license at runtime without shutting down your nodes. License updates take effect immediately. The license is provided as a JSON file that you install with the update license API.
You can use the get license API to retrieve the currently installed license.