Installing the enqueue replication server as an ERS instance

Virtual host name for the ERS instance

A stand-alone ERS instance requires a virtual host name, which was not used in older SAP installations and therefore was often chosen to be the same as the virtual host name of its associated central services instance. The *SAPSRV add-on policy requires that you install ERS with its own virtual host name. Therefore, you must use a different additional virtual host name, the ERS virtual host name. The advantages of defining the ERS instance with its own virtual host name are:

• It is more consistent to have a separate set of virtual host names for each ERS and its associated SCS or ASCS.
• A separate virtual host name for the ERS instance allows easier monitoring of the ERS or identification of the host on which it is running. Its VIPA is active on the host on which the ERS instance is running.

The VIPA / virtual host name is not used by the ERS itself because the ERS itself does not listen for client connect requests. But the VIPA must be active on the ERS LPAR such that the ERS sapstartsrv process can be reached from a remote host to start, stop, and monitor the ERS instance.