To setup Real User Monitoring please follow the monitoring setup guide and make sure 'Collect Performance' is flagged:
The data is kept for 14 days, this setting can not be changed at the moment.
There is no direct impact on the end-users.
For ABAP based systems a job is scheduled collecting every few minutes (depending on the entered collection period) for each use case the data. These collections are started via aRFC if enough work processes (WP) are free. The runtime depends an the amount of data to be collected.
In case you encounter problems configuring or using SAP Cloud Application Lifecycle Management, please report an incident using one of the following components: