License master is used for the purpose of indexing the right amount of data effectively. It helps to limit the environment to use only a limited amount of storage as per the purchased volume via license throughout the time period in a balanced way.  License master helps to control all its associated license slaves. It provides its slaves access to Splunk Enterprises license. After configuring a License master instance and adding license slaves to it, license slaves make a connection with the license master every minute.  Due to any reason, if the license master is not reachable or not available then a 72 hours timer is started by the license slave. If the license master is still not able to connect with the license slave after completion of 72 hours, then the search is blocked on the license slave, but the indexing process still continues which means that the Splunk deployment receives data and is also indexed. Users will not be able to search data in license slaves until the connection is built again between license slave and license master. When the indexing limit is reached then the user will get a warning to reduce the data intake. Users can upgrade their storage licenses to increase volume capacity.