SAP Message RT193 - Transactional RFC and queued RFC

Diagnosis
This monitoring tree in the CCMS alert monitor watches over activity inthe transactional RFC and queued TRFC facilities.
Transactional RFC (tRFC, Remote Function Calls) is a facility fortransferring data between SAP systems or between an SAP system and anexternal component. tRFC ensures the following:

  • that an RFC is carried out once and only once in a target system.

  • that all of the RFCs that are grouped into an LUW (Logical Unit of Work)
    • are carried out or that none of the functions is carried out.
    These features of tRFC let programmers transfer data between systemswith the same safety and reliability that normal transactions allowwithin a single SAP system.
    Relationship to ALE: ALE (Application Link Enabling), one of thebasic technologies of the SAP Business Framework Architecture, is one ofthe most important users of tRFC. ALE uses tRFC as one of its methodsfor echoing data changes from one system or component to another. tRFCcalls that carry the term 'IDOC' in the function name are ALE calls.
    ALE provides mechanisms for recovering from errors in transferring databetween systems. You should therefore always check with the ALEadministrator before running or deleting a tRFC "IDOC" call, one thatwas generated by ALE.
    Queued RFC (qRFC) is an enhancement of tRFC. In qRFC, tRFC callsare serialized by means of output and input queues. qRFC withoutput queues ensures that (tRFC) calls are executed at the targetdestination in exactly the order in which the calls were added to thequeue. Both qRFC output queue and normal tRFC calls are held in theARFCSSTATE table. Both types of calls are deleted from the ARFCSSTATEtable as soon as they have been executed. Calls in the ARFCSSTATE tableare therefore usually there because there was some problem in runningthem, such as a communication or execution error (status CPICERR orSYSFAIL) or a blocked qRFC output queue. qRFC input queue calls areheld in a separate table.
    qRFC with input queues ensures that calls coming in to a systemfor a particular queue are executed in the order in which they arrive.qRFC with input queues is used primarily as a load-control mechanism, toprevent an RFC server from being overloaded by calls arriving inparallel from different senders. qRFC with input queues calls are heldin table ARFCRSTATE. As with the ARFCSSTATE table, calls are usuallydeleted immediately when they have been executed.

    Procedure
    Monitoring tRFC activity: Normally, few or no tRFC calls should bewaiting in the ARFCSSTATE table. Further, none should show an errorcondition: CPI-C Error or System Fail or System Load. There shouldalso be no qRFC queues that are blocked because of calls with errors.You can check for problems using the ARFCSSTATE section of themonitoring tree. It shows only tRFC calls.
    The alert monitor's analysis methods give you access from this monitorto the tools for tRFC and qRFC display and trouble-shooting.
    Monitoring qRFC activity: The monitor reports on errors that stopprocessing in inbound or outbound qRFC queues. You can also monitor thetotal number of calls in the ARFCRSTATE table, in which inbound qRFCcalls for this system are held.
    You should respond to a queue error alert promptly if you have CRM, APO,BW, or other SAP New Dimensions components installed in your system. Ifthere is a lot of activity in a blocked queue, then the ARFCSSTATE andARFCRSTATE tables can quickly become large enough to cause spaceproblems in the database.