Flexible License MechanismLocate this document in the navigation structure

Definition

The flexible license mechanism extends the previous license procedure in such a way that the license for a system is no longer connected to the hardware for a message server. This means that the license remains valid, even if you move the message server to another server. This is primarily important for high-availability environments and for Adaptive Computing, since systems and system components often have to be moved between servers in these situations.

The flexible license mechanism does not assess the hardware ID of the message server, but rather uses a separate ID generator, which is implemented in the SAPHostControl process. This generator calculates a unique ID for each message server based on the following data:

  • Hardware ID of the ID generator

  • Network parameters of the message server itself

  • Network connection between the message server and the ID generator

If you are using virutal IP addresses, you can move the network ID together with the message server to another host, and therefore retain the unique ID. The only thing you cannot move is the ID generator.

Figure 1: Architecture of the License Mechanism

The illustration shows the following process:

  • As soon as a user logs on, the license is checked. The AS ABAP application servers can be started with or without a valid license. The SAP* user can also log on to the system without a license check.

  • The applicaiton server (consisting of a dispatcher and work processes) searches in the database for a suitable, valid license.

  • The validity of the license depends, among other things, on the hardware ID provided by the message server.

  • If the flexible license mechanism is set up, the message server no longer uses its local hardware ID, but rather uses the SAPHostControl ID generator to determine a network ID that is used instead of the hardware ID.

The message server requests a network ID when starting and at periodic intervals. If you are using multiple ID generators, the first valid response is used. If the message server does not receive a valid response when starting, or during a 24 hour period of operation, it uses the local hardware ID. The message server then requests a valid network ID every five minutes.

Integration

Licenses based on network IDs are not a solution for scenarios for which licenses need to be independent of both the hardware and the network. This means that in a DHCP environment, you cannot move the message server to a different subnet (for which a different IP address is usually required).

Adaptive Computing and most high-availablity solutions do not use this approach. However, some HA solutions support this using dynamic DNS reconfiguration. These scenarios are not covered by the network ID approach. HA solutions can, however, use multiple (usually two) ID generators. In this case, each system requires two licenses, one for each ID generator.