ndb - bug#20895

  Fix occational LCP hang!!!
  Make sure only to consider alive nodes in startNextChkpt


ndb/src/kernel/blocks/dbdih/DbdihMain.cpp:
  Make sure only to consider alive nodes in startNextChkpt

ndb/src/kernel/blocks/dbdih/DbdihMain.cpp

@@ -9561,15 +9561,19 @@ void Dbdih::startNextChkpt(Signal* signal)
       nodePtr.i = replicaPtr.p->procNode;
       ptrCheckGuard(nodePtr, MAX_NDB_NODES, nodeRecord);
       
+      if (c_lcpState.m_participatingLQH.get(nodePtr.i))
+      {
 	if (replicaPtr.p->lcpOngoingFlag &&
-          replicaPtr.p->lcpIdStarted < lcpId) {
+	    replicaPtr.p->lcpIdStarted < lcpId) 
+	{
 	  jam();
 	  //-------------------------------------------------------------------
 	  // We have found a replica on a node that performs local checkpoint
 	  // that is alive and that have not yet been started.
 	  //-------------------------------------------------------------------
 	  
-        if (nodePtr.p->noOfStartedChkpt < 2) {
+	  if (nodePtr.p->noOfStartedChkpt < 2) 
+	  {
 	    jam();
 	    /**
 	     * Send LCP_FRAG_ORD to LQH
@@ -9587,7 +9591,9 @@ void Dbdih::startNextChkpt(Signal* signal)
 	    nodePtr.p->noOfStartedChkpt = i + 1;
 	    
 	    sendLCP_FRAG_ORD(signal, nodePtr.p->startedChkpt[i]);
-        } else if (nodePtr.p->noOfQueuedChkpt < 2) {
+	  } 
+	  else if (nodePtr.p->noOfQueuedChkpt < 2) 
+	  {
 	    jam();
 	    /**
 	     * Put LCP_FRAG_ORD "in queue"
@@ -9603,10 +9609,13 @@ void Dbdih::startNextChkpt(Signal* signal)
 	    nodePtr.p->queuedChkpt[i].fragId = curr.fragmentId;
 	    nodePtr.p->queuedChkpt[i].replicaPtr = replicaPtr.i;
 	    nodePtr.p->noOfQueuedChkpt = i + 1;
-        } else {
+	  } 
+	  else 
+	  {
 	    jam();
 	    
-	  if(save){
+	    if(save)
+	    {
 	      /**
 	       * Stop increasing value on first that was "full"
 	       */
@@ -9615,7 +9624,8 @@ void Dbdih::startNextChkpt(Signal* signal)
 	    }
 	    
 	    busyNodes.set(nodePtr.i);
-	  if(busyNodes.count() == lcpNodes){
+	    if(busyNodes.count() == lcpNodes)
+	    {
 	      /**
 	       * There were no possibility to start the local checkpoint 
 	       * and it was not possible to queue it up. In this case we 
@@ -9628,6 +9638,7 @@ void Dbdih::startNextChkpt(Signal* signal)
 	  }//if
 	}
       }//while
+    }
     curr.fragmentId++;
     if (curr.fragmentId >= tabPtr.p->totalfragments) {
       jam();