Sometimes there is a need to forcibly close the RFC connection after calling some RFC module. There can be many reasons, but more importantly, how to do it?
The functional module RFC_CONNECTION_CLOSE will help us with this. Below I will give an example of calling this FM for greater clarity:

  CALL FUNCTION 'RFC_CONNECTION_CLOSE' 
    EXPORTING 
      destination = lv_rfc 
    EXCEPTIONS 
      OTHERS      = 0.  

We simply call this FM and the RFС closes the connection.
Where lv_rfs is the connection we previously opened, for example using destination lv_rfs.

Close RFC connection example ABAP

I will also give a more complete example with a call to FM through the RFС and the subsequent closing of this connection in SAP system in ABAP program.

  SELECT SINGLE rfcdest
    INTO @DATA(lv_rfc)
    FROM smof_erpsh
    WHERE sitetypeid = 'ERP_SYST'.

  CALL FUNCTION 'Z_GET_DATA' DESTINATION lv_rfc
    EXPORTING
      i_rezerv = 'X'
      iv_vbeln = lv_vbeln
    IMPORTING
      et_data    = lt_data.

  CALL FUNCTION 'RFC_CONNECTION_CLOSE' 
    EXPORTING 
      destination = lv_rfc 
    EXCEPTIONS 
      OTHERS      = 0.