How SPLA Licensing Works in a Cluster

blog header clusterRecently, we received a lot of questions from licensing managers on cluster server licensing, specifically SQL Server.

Here is a brief summary of licensing Microsoft SQL clustering for failover/DR scenarios. SQL clustering can get confusing, especially when virtual machines are moving between hosts, SPLA reporting can quickly become troublesome.  One best practice is to label servers as “passive” in order to visualize it on your license usage reporting.


There are two ways for licensing managers to license SQL:

  • by SAL’s, which is an option if you perform a break-even cost analysis of users versus cores, but is only available for Standard versions. 
  • The other option is to license by Cores (the only option for SQL Enterprise and Web). For Cores you need to license an active instance with a minimum of 4 cores, you are then entitled to a passive SQL instance (also known as fail over rights) & or a DR SQL instance.  


In our experience, most SQL replication scenarios are categorized as “always-on” and therefore considered passive/failover, as DR is only permitted by Microsoft for temporary use.


Supporting SPLA licensing information/extracts:

Fail-Over Rights: 

Permits customers to run passive fail-over instances of the product in conjunction with software running on the licensed server, in anticipation of a fail-over event.

Passive fail-over instances may be running in either a separate OSE on the licensed server or on a different server dedicated to the customer’s use.

Failover rights apply only if the number of licenses that otherwise would be required to run the passive fail-over instances does not exceed the number of licenses required to run the corresponding production instances.


Disaster Recovery Rights: 

For each instance of eligible server software licensed in the Per Processor, Per Core (Applications), Per Core (OS), or Per Core (Management) licensing models that the customer runs in a physical OSE or virtual OSE on a licensed server, the customer may temporarily run a backup instance in a physical OSE or virtual OSE on a server dedicated to disaster recovery.

The license terms for the software and the following limitations apply to customers’ use of software on a disaster recovery server.

Permitted Periods of Use

The disaster recovery server can run only during the following exception periods:

  • For brief periods of disaster recovery testing within one week every 90 days.
  • During a disaster, while the production server being recovered is down.
  • Around the time of a disaster, for a brief period, to assist in the transfer between the primary production server and the disaster recovery server.

Thanks for reading,


Back to Blog