RFC

Deleting unwanted entries from RFC tables (ARFCSSTATE, ARFCSDATA etc.) - https://help.sap.com/docs/SUPPORT_CONTENT/abapconn/3354079553.html

2542374 - Troubleshooting delays seen in RFC calls

2548815 - Performance issue with RFC processing with a large amount of entries in ARFC Table

2418936 - High RFC time: Performance troubleshooting