3737602 - Content Server Repository access fails with Communication link failure;-10709 Connection failed (RTE:[1] database connect, protocol error)

• Attempting to create a content repository or accessing an SAP Content Server an error occurs. The complete description of the error is visible in the Content Server URL:

            "SQLConnect failed: [SAP AG][LIBSDBOD SO][SAP MaxDB] Communication link failure;-10709 Connection failed (RTE:[1] database connect, protocol error)

• The error from application side is too generic, it requires to check MaxDB log files for further details. This documents shows following possible reason and solution.
  
  MaxDB KnlMsg：
  

  ERR IPC        11311:  idfile: '/usr/spool/sql/ipc/db:<SID>//-m1966128' open error, Too many open files
  ERR IPC        11285:  create_shm: creating id file failed
  ERR RTEIPC        27:  A dynamic communication segment for task 110 could not be created,UNIX_PERMISSIONS=0600,BYTE_SIZE=524472,_FILE=RTECKC_KernelLegacyCommunicationSegmentUNIX+noPIC.cpp,_LINE=142

• SAP Content Server

• 10709, communication link failure, protocol error, maxdb, database connect, sqlconnect failed, too many open files, open files limit, ulimit, ipc, create_shm, idfile open error, RTEIPC 27, content server, connection failed