The Software Update Manager is equipped with a procedure to split off the ASCS from the primary application server instance, which creates a new ASCS instance that runs on the primary application server. The split is optional on systems with a single instance setup, and it is mandatory for systems with a multi-instance setup.

Since the stand-alone enqueue server is the future, we strongly recommend using the stand-alone enqueue server as the better solution. It offers better performance and better scalability for large systems (two or more additional application server instances). In addition, it is already the standard for all new installations and mandatory for high availability setups. In future releases, it becomes mandatory for all systems.

As of SAP NetWeaver 7.50, the enqueue work process used within multi-instance systems is not supported anymore for the following scenarios:

• Conversion of SAP systems to S/4HANA

• Upgrade or Update to SAP Business Suite 7 Innovation 2016 based on SAP NetWeaver 7.5 or a higher SAP NetWeaver version

For more information about the desupport of the enqueue work process, see SAP Note 2146940 .

If the Software Update Manager detects in the Checks roadmap step that you are using a system with a multi-instance setup (one primary application server instance and several additional application server instances), the ASCS instance split is mandatory and performed automatically. You are informed in the CHECKS.LOG file that the ASCS instance split takes place.

If you are using a system with a single instance setup (classical primary application server instance), the Software Update Manager prompts you in a dialog (phase ASCS_ASK of the Checks roadmap step) to select one of the following options:

• Perform the ASCS instance split

• Keep the current system setup

The ASCS split is optionally possible for updates with target release SAP NetWeaver 7.4 or higher, or if you carry out an update including the database migration option (DMO) of the Software Update Manager.

Note that the usage of the enqueue work process is still possible for systems with single instance setup. However, we strongly recommend to perform the ASCS split and to migrate to a setup with a stand-alone enqueue server.