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2196513 - ENSA threads with: "NiICreateHandle: no more free handles (XXXX)" or "maximum of sockets reached" errors


  • In SM50/SM66 some work processes are waiting for locks, showing STOP/ON HOLD status with reason ENQ and program SAPLSENA.

  • Error "Operating system call recv failed" and "ENQ ... Q47 connection errors have occurred in succession" might appear at the system log (transaction SM21)

  • Exception CONNECT_TO_ENQ_SERVER_FAILED is occurring in ST22 (RAISE_EXCEPTION shortdump)

  • The following (or similar) entries are observed at the "dev_enqio_<IO thread number>" or "dev_enqlisten" trace files:

    [Thr <number>] *** ERROR => NiCreateHandle: no more free handles (XXXX)
    [Thr <number>] *** ERROR => NiIAccept: NiCreateHandle (rc=-8)
    [Thr <number>] SiSelEPAdd: maximum of sockets reached (<connections>)
    [Thr <number>] *** ERROR => NiBufISelUpdate: set failed for hdl 5763 set1; maxSockets reached (<connections>)
  • System is hanging with poor performance and high response times.

  • The Standalone Enqueue server is slow, most enqueue requests were delayed.



  • SAP NetWeaver
  • Client/Server Technology - Standalone Enqueue Server (ENSA)
  • SAP Web Application Server for SAP S/4 HANA
  • ABAP PLATFORM - Application Server ABAP


ABAP platform all versions ; SAP NetWeaver all versions ; SAP Web Application Server for SAP S/4HANA all versions


ASCS, Standalone, Enqueue Server, ENSA, SCS, Stand alone, ENQ, no more free handles, maximum of sockets reached, enque/server/max_clients, enque/server/threadcount, enque/server/replication , KBA , BC-CST-EQ , Enqueue , Problem

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