In a Replication environment what Hardware Key to use to generate a License key for SAP HANA Database

I would like to highlight some important information regarding the license and hardware keys for SAP HANA Database if it is involved in replication/DR.

Let’s start with the license keys:

We all know we can check the license and hardware keys in few places.

• Using HANA Studio, by doing the following:
  1. Login to HANA DB
  2. Right click the server name and select properties
  3. Then select License
  4. Under System License:

1. We see the Hardware key
2. And the license key

• 1. Now there is another tab there it is called All Licenses. In there you will see the history of all licenses involved. The question is how to fetch this information from the Database? We all know we can execute this query SELECT * FROM M_LICENSE and that will give us the same details that we have in the License Tab in HANA Studio. To get all the licenses, please check this KBA 2775168 – How to Check SAP HANA Hardware License Key
• Next question is, why there are different Hardware Keys on the same machine when accessing M_LICENSE and M_LICENCES?
  1. This is expected behavior because
     1. If SAP HANA was re-installed
     2. If SAP HANA was restored/recovery
  2. The main view to fetch the correct information is either the SYSTEM LICENSE or M_LICENSE

• The other question now if I need to license replication/stand by nodes, which system I should use to fetch the Hardware Key

In a replication, stand by node, what is matter is the Hardware key for the primary node because, it will be replicated to all other nodes. The Hardware key will be stored in a global directory which is common for all nodes. That’s why we do not need to license the standby node(s). For more information check KBA 2112327 – HANA: Where is the Hardware Key stored?

• Now that we know all that, comes the third question which is when the other node(s) take over, which Hardware key should be used? Is it the original primary or the new primary?

This is a very good question. In this case, it will always be the original primary because once replication is defined, the stand by node its Hardware key will not be used. It will always be the Hardware Key of the original primary node.

In Summary:

• When it comes to license and Hardware key, use either SAP HANA Cockpit,  HANA Studio or M_LICENSE
• When it comes to generating a license for replication environment, always use the Hardware key of the primary