2726119 - SAP IQ secondary node aborts with 'blockmap userlocked during flush' message from ev_begintxn event session

SAP IQ secondary node aborts with 'blockmap userlocked during flush' message from ev_begintxn event session.

--.iqmsg & stacktrace

Collation 936ZHO, Case Respect, Blank Padding On, Comparisons are Conditioned
Txn 321054019 0 321054134
Connect:  SA connHandle: 1004754404  SA connID: 9  IQ connID: 0007794776  User: dbo
ev_begintxn started
...
TxnWt 321054147 0 321054157
blockmap userlocked during flush; _blockmap @ 0x4449a3b8
Blockmap Member Variables for 0x4449a3b8
From dblib/db_table.cxx:3154
  _nextPartitionForHelperFlush = 0
                  IsEBufNoWait = 0
               IsProxyFreelist = 0
                _OrigRootBlock = 1514635339
                          _Bio = 0x1ee2d88
                    _tempSpace = 0
                       _Bufman = 0x2aa5008 main Bufman
            _allocFromLastLink = 1
                       _isMeta = 1
                  _m_dbspaceID = 16387
                    _dbspaceID = 16387
                  _rangePIDmap = 0
                _useGlobalLBNs = 0
           _isDistributedOwner = 0
                    _LBNOffset = 1
                      _LBNBase = 1
                _nextGlobalLBN = 1
                     _RWAccess = 1
                  _gotIdentity = 0
     _gotIdentityWithNoEntries = 0
          _allocationPrivilege = 0
                     _pageInfo = 0x4c600a08
                 _perConnStats = 0x4ad58828
              _tmp_rangePIDmap = 0
              _nPhysicalWrites = 0
               _nPhysicalReads = 8
                 _LockRefCount = 1
             _PrefetchRefCount = 0
             _ScanModeRefCount = 0
                    _DirtyList = 0x1707ac48
              #DirtyReferences = 0
                   #DirtyLinks = 0
                        _pnext = 0x4a781558
                        _pprev = 0x5d03e618
                    _cacheSize = 0
                        _cache = 0
                        _nBlks = 0
              _leaderCxtCursor = 0
                  _allowToFree = 0
                       _psuAll = 0
[s_blockmap_identity]
_UniqueId: 604409
_RootBlockId: 1514635339
_NEntries: 18
_LastWriterTxnId: 321054147
_LastWriterSavePoint: 3
_FanOutAndFlags2: 0x8
_Flags: 0xcd
_Version: 1
_NLinks: 1
_EntriesPerLink: 19959
_FirstAvailLink: 0
_MaxLink: 1
_ModNum: 4080
_RootModNum: 4079
[end s_blockmap_identity]

**************************************************
***   SAP IQ Abort:
***      From:  slib/s_bufman.cxx:5764
***      PID: 22151
***      Message: blockmap userlocked during flush
***      Thread: 139922170234624  (TID: 30)
**************************************************

    **  Error from IQ connection:  SA connHandle: 1004754404  SA connID: 9  IQ connID: 0007794776  User: dbo
    **  Time of error:  2018-11-21 22:10:40
    **  IQ Version:  SAP IQ/16.0.110/10940/P/sp11.19
    **  OS info:  IQ built on: Enterprise Linux64 - x86_64 - 2.6.18-194.el5,  Executed on: Linux/HOSTNAME/2.6.32-696.3.1.el6.x86_64/#1 SMP Thu Apr 20 11:30:02 EDT 2017/x86_64
    **  Command status when error occured:  COMMAND ACTIVE
    **  Command text:
Statement text unavailable
Dump all thread stacks at slib/s_bufman.cxx:5764 for PID: 22151
===== Thread Number  139922170234624  (IQ connID: 0007794776) =====
pcstkwalk
ucstkgentrace
DumpAllThreads
hos_ABORT
s_bufman::PrivateFlush
s_bufman::FlushToDisk
st_txncb::FlushCoalesce
st_txncb::FlushForCommit
st_txnMgr::FlushForCommit
st_command::DoCmdThroughResourceGate
st_iqtxn::FlushForCommit
UIQTxn_FlushForCommit+0x15
st_SAIQInterfaceInfo::callFunction
st_SAIQInterface::RunIQFunc
st_SAIQInterface::Execute
saint_iqthresholdtxn::FlushForCommit
ri_commit
Connection::commit_work
_ri_auto_commit
drop_table_or_view
DoExecuteStmt
exec_procedure_stmt
run_procedure
call_procedure
dbi_stmt_batch
DoExecuteStmt
db__execute_str
Connection::ExecMpxRPC
sp_iqmpxddlrunas2_internal
RunInternalProcedure
process_ext_int_remote_call
process_call
exec_procedure_stmt
run_procedure
dbi_call_user_function
dfe_FactoryUserFunction::PreBuildValAndArgs
dfe_Builder::DoBuildPrepExprValue
dfe_Builder::BuildPrepExprValueDom
dbi_assignvar
process_assign
exec_procedure_stmt
run_procedure
call_procedure
DB_Exec_event_handler
EventHandler::do_request
Worker::spawn
RQInternalBaseItem::do_work
RequestQueue::worker_body
request_task
run_task_body+0x2d
******************* End of STACKTRACE ******************

• SAP IQ 16.0 SP11.19
• Multiplex Secondary node

"blockmap userlocked during flush"; "ev_begintxn"; "s_bufman::PrivateFlush"; "s_bufman::FlushToDisk"; "st_txncb::FlushCoalesce"; "st_txncb::FlushForCommit"; "st_txnMgr::FlushForCommit"; , KBA , BC-SYB-IQ , Sybase IQ , BW-SYS-DB-IQ , BW on HANA with Sybase IQ Near-line Storage , Problem