Hello Henk,
Just to add to what Srinivas has already mention, if there are too many logs getting generated and you want to keep a control over what logs & traces should be generated by PI, please refer to the link https://help.sap.com/saphelp_nw73/helpdata/en/48/aeb18c5bb5356be10000000a421937/content.htm
Go to component based on AS Java and follow the instruction to increase severity of the logs/traces to be recorded for locations (PI related components and their locations are also mentioned in the above link).
Regards,
Ankit