Now we expected that the configurations are visible in the DSS or the System Settings but this is not the case.
prconfig.xml environment entries reside in the filesystem and are specific to a PRPC Node. Dynamic System Settings are instances of Data- which resides in the PRPC database and are applicable to all nodes in a PRPC cluster. During PRPC engine startup (by default) the prconfig entries that reside in the database table as DSS are merged with the ones in the filesystem (prconfig.xml) and a resultant configuration map is loaded into the server's heap memory. If the same entry resides both in database as DSS and in prconfig.xml then the values in prconfig.xml are taken into consideration. Or in other words env entries in prconfig.xml overrides the ones in DSS.
Is this expected behaviour?
Yes, the behavior you are observing is the expected behavior.
Is there any way to verify that these settings are actually used?
You can verify the prconfig entries from SMA. Navigate to -
I. Administration > Configuration Management > All details on the screen on right hand side shows the runtime configuration map.
II. Administration > Configuration Management > Click “Display prconfig” on bottom of screen > All details on the screen shows the the prconfig.xml entries that were read by the server during startup.
Could we set these settings in the DSS or System Settings directly? If yes, where?
Yes, Create new instances of Dynamic System Settings in the format below -