ndb - bug#25286

  - add some sanity check to marker/hash code to see that element isnt inserted twice into hashtable
    (if defined VM_TRACE or ERROR_INSERT)

  - allow REMOVE_MARKER_ORD to fail(dont find record) in release


storage/ndb/src/kernel/blocks/dblqh/DblqhMain.cpp:
  add a bunch of sanity check ifdef#vmtrace of #error_insert
storage/ndb/src/kernel/blocks/dbtc/DbtcMain.cpp:
  add a bunch of sanity check ifdef#vmtrace of #error_insert

storage/ndb/src/kernel/blocks/dblqh/DblqhMain.cpp

@@ -2480,8 +2480,16 @@ Dblqh::execREMOVE_MARKER_ORD(Signal* signal)
   
   CommitAckMarkerPtr removedPtr;
   m_commitAckMarkerHash.remove(removedPtr, key);
+#if defined VM_TRACE || defined ERROR_INSERT
   ndbrequire(removedPtr.i != RNIL);
   m_commitAckMarkerPool.release(removedPtr);
+#else
+  if (removedPtr.i != RNIL)
+  {
+    jam();
+    m_commitAckMarkerPool.release(removedPtr);
+  }
+#endif
 #ifdef MARKER_TRACE
   ndbout_c("Rem marker[%.8x %.8x]", key.transid1, key.transid2);
 #endif
@@ -3406,7 +3414,7 @@ void Dblqh::execLQHKEYREQ(Signal* signal)
     markerPtr.p->tcNodeId = tcNodeId;
     
     CommitAckMarkerPtr tmp;
-#ifdef VM_TRACE
+#if defined VM_TRACE || defined ERROR_INSERT
 #ifdef MARKER_TRACE
     ndbout_c("Add marker[%.8x %.8x]", markerPtr.p->transid1, markerPtr.p->transid2);
 #endif
@@ -9630,7 +9638,7 @@ Uint32 Dblqh::initScanrec(const ScanFragReq* scanFragReq)
   active.add(scanptr);
   if(scanptr.p->scanKeyinfoFlag){
     jam();
-#ifdef VM_TRACE
+#if defined VM_TRACE || defined ERROR_INSERT
     ScanRecordPtr tmp;
     ndbrequire(!c_scanTakeOverHash.find(tmp, * scanptr.p));
 #endif
@@ -9754,7 +9762,7 @@ void Dblqh::finishScanrec(Signal* signal)
   scans.add(restart);
   if(restart.p->scanKeyinfoFlag){
     jam();
-#ifdef VM_TRACE
+#if defined VM_TRACE || defined ERROR_INSERT
     ScanRecordPtr tmp;
     ndbrequire(!c_scanTakeOverHash.find(tmp, * restart.p));
 #endif

storage/ndb/src/kernel/blocks/dbtc/DbtcMain.cpp

@@ -2825,6 +2825,12 @@ void Dbtc::execTCKEYREQ(Signal* signal)
         tmp.p->apiNodeId     = refToNode(regApiPtr->ndbapiBlockref);
         tmp.p->apiConnectPtr = TapiIndex;
         tmp.p->noOfLqhs      = 0;
+#if defined VM_TRACE || defined ERROR_INSERT
+	{
+	  CommitAckMarkerPtr check;
+	  ndbrequire(!m_commitAckMarkerHash.find(check, *tmp.p));
+	}
+#endif
         m_commitAckMarkerHash.add(tmp);
       }
     }
@@ -8115,6 +8121,13 @@ void Dbtc::initApiConnectFail(Signal* signal)
     tmp.p->noOfLqhs      = 1;
     tmp.p->lqhNodeId[0]  = tnodeid;
     tmp.p->apiConnectPtr = apiConnectptr.i;
+
+#if defined VM_TRACE || defined ERROR_INSERT
+    {
+      CommitAckMarkerPtr check;
+      ndbrequire(!m_commitAckMarkerHash.find(check, *tmp.p));
+    }
+#endif
     m_commitAckMarkerHash.add(tmp);
   } 
 }//Dbtc::initApiConnectFail()
@@ -8271,6 +8284,12 @@ void Dbtc::updateApiStateFail(Signal* signal)
       tmp.p->noOfLqhs      = 1;
       tmp.p->lqhNodeId[0]  = tnodeid;
       tmp.p->apiConnectPtr = apiConnectptr.i;
+#if defined VM_TRACE || defined ERROR_INSERT
+      {
+	CommitAckMarkerPtr check;
+	ndbrequire(!m_commitAckMarkerHash.find(check, *tmp.p));
+      }
+#endif
       m_commitAckMarkerHash.add(tmp);
     } else {
       jam();