The system ID or system name is stored in a System data instance (Data-Admin-System class) record. You choose a system name during installation. A PRPC 'system' in this context is all PRPC instances (nodes) that share a single database and the same system name.
You can change the system name at any time from the value you choose during installation. Use the System Name tab on the System Settings landing page ( > System > Settings > System Name) to change the current system name of a PRPC system and all associated Data instances, including the node name of all other nodes in the system that use the current system name.
As a best practice, choose a distinct system name for each of the systems (such as development, test, quality-assurance, or production) in your organization. All nodes in one system have a common system name. The system names prpc and IWM are reserved. Do not use this name.
When you create, or update a rule or a data instance, the current system name is added to the History tab. When you import a ZIP archive containing a rule or data instance, the system name on the History tab (which may be the source system on which the ZIP archive was created).
The current system name is identified on the System Name landing page and on the clipboard Process page by the property pxProcess.pxAdminSystem.pxSystemName. (Your system may contain multiple Data-Admin-System data instances. You can't determine which one of these is current from the data instances themselves.)
Do not confuse system with node. One PRPC system can consist of multiple server nodes in a cluster. Also, one server computer can host simultaneous operation of two or more distinct, unrelated PRPC systems, subject performance and capacity limitations. Both the system ID and the node ID (or node Short Description) appear by default on the login form.