public NodeBalanceData(ArrayList hashMap, Hashtable bucketStatistics, ArrayList members)
{
_percentWeightPerNode = 100 / members.Count;
_members = members;
int memberCount = _members.Count;
_hashMapData = new ArrayList(memberCount);
_cacheDataSum = 1;
ArrayList _weightIdList = new ArrayList();
for (int i = 0; i < DistributionManager.TotalBuckets; i++)
{
HashMapBucket hmapBuck = (HashMapBucket)hashMap[i];
BucketStatistics buckStats = (BucketStatistics)bucketStatistics[i];
if (hmapBuck.Status != BucketStatus.UnderStateTxfr) //include only those buckets that are Functional
{
WeightIdPair listItem = new WeightIdPair(hmapBuck.BucketId, buckStats.DataSize, hmapBuck.PermanentAddress);
_weightIdList.Add(listItem);
}
_cacheDataSum += buckStats.DataSize; //Lets get the TOTAL weight of the cluster.
}
_weightPerNode = _cacheDataSum / memberCount;
_balanceDataListForNodes = new ArrayList(memberCount);
foreach (Address mbr in _members)
{
BalanceDataForNode balanceData = new BalanceDataForNode(_weightIdList, mbr, _cacheDataSum);
_balanceDataListForNodes.Add(balanceData);
}
}
public NodeBalanceData(ArrayList hashMap, Hashtable bucketStatistics, ArrayList members)
{
_percentWeightPerNode = 100/members.Count;
_members = members;
int memberCount = _members.Count;
_hashMapData = new ArrayList(memberCount);
_cacheDataSum = 1;
ArrayList _weightIdList = new ArrayList();
for (int i = 0; i < DistributionManager.TotalBuckets; i++)
{
HashMapBucket hmapBuck = (HashMapBucket)hashMap[i];
BucketStatistics buckStats = (BucketStatistics)bucketStatistics[i];
if (hmapBuck.Status != BucketStatus.UnderStateTxfr) //include only those buckets that are Functional
{
WeightIdPair listItem = new WeightIdPair(hmapBuck.BucketId, buckStats.DataSize, hmapBuck.PermanentAddress);
_weightIdList.Add(listItem);
}
_cacheDataSum += buckStats.DataSize; //Lets get the TOTAL weight of the cluster.
}
_weightPerNode = _cacheDataSum / memberCount;
_balanceDataListForNodes = new ArrayList(memberCount);
foreach (Address mbr in _members)
{
BalanceDataForNode balanceData = new BalanceDataForNode(_weightIdList, mbr,_cacheDataSum);
_balanceDataListForNodes.Add(balanceData);
}
}
private void ApplyChangesInHashMap(BalanceDataForNode secNode)
{
ArrayList weightIdPair = secNode.WeightIdList;
Address newAddr = secNode.NodeAddress;
HashMapBucket bucket = null;
foreach (WeightIdPair widPair in weightIdPair)
{
bucket = (HashMapBucket)_hashMap[widPair.BucketId];
if (!newAddr.Equals(bucket.TempAddress))
{
bucket.Status = BucketStatus.NeedTransfer;
}
bucket.TempAddress = newAddr;
}
}
//Need to check if the source node really needs any balancing?. If the weight is more then the Avg weight/Node then its true else false.
private bool SanityCheckForCandidateNode(Address sourceNode)
{
ArrayList dataListForNodes = _nodeBalData.BalanceDataListForNodes;
foreach (BalanceDataForNode balData in dataListForNodes)
{
if (balData.NodeAddress.Equals(sourceNode))
{
if (balData.PercentData > _nodeBalData.PercentWeightPerNode)
{
this._weightToMove = balData.TotalWeight - this._nodeBalData.WeightPerNode; //Weight to move is the one that is above the Avg. weight the node Should bear.
_primaryNode = balData;
return(true);
}
else
{
return(false);
}
}
} //end foreach loop
return(false); //nothing found.
}
public DistributionMaps BalanceNodes(DistributionInfoData distInfo, ArrayList hashMap, Hashtable bucketStats, ArrayList members)
{
_hashMap = hashMap;
_nodeBalData = new NodeBalanceData(hashMap, bucketStats, members);
//Check if any other state transfer is not in progress...
bool bAllFunctional = this.SanityCheckForAllFunctional(hashMap);
//Add some status saying that node balancing is not possible at the moment.
if (!bAllFunctional)
{
DistributionMaps result = new DistributionMaps(BalancingResult.AlreadyInBalancing);
return(result);
}
//Check if really the node needs some balancing or not.
bool bShouldBalance = this.SanityCheckForCandidateNode((Address)distInfo.AffectedNode.NodeAddress);
if (!bShouldBalance)
{
DistributionMaps result = new DistributionMaps(BalancingResult.NotRequired);
return(result);
}
ArrayList dataListForNodes = _nodeBalData.BalanceDataListForNodes;
ArrayList candidates = FilterCandidateNodes();
foreach (AddressWeightPair awPair in candidates)
{
BalanceDataForNode secNode = GetBalDataForNode(awPair.NodeAddress);
BalanceTwoNodes(_primaryNode, secNode, awPair.WeightShare);
ApplyChangesInHashMap(secNode);
}
ApplyChangesInHashMap(_primaryNode);
return(new DistributionMaps(_hashMap, null));
}
//data to be moved from Primary node to the secondary node.
//As a result priNode and secNode got updated WeightIdPairLists.
private static void BalanceTwoNodes(BalanceDataForNode priNode, BalanceDataForNode secNode, long dataToMove)
{
int priBucketCount = priNode.ItemsCount;
int secBucketCount = secNode.ItemsCount;
ArrayList priWIPairList = priNode.WeightIdList;
ArrayList secWIPairList = secNode.WeightIdList;
int cushionFactor = 10; // 10% cushion for balancing... +- 10%
long swapWeightGain = 0; // weight gain for this swap
long cushionWeight = Convert.ToInt64(((double)(dataToMove * cushionFactor) / (double)100));
bool bTargetAchieved = false; //loop-invariant, in case we need to exit the loop in middle.
long movedSoFar = 0;
ArrayList usedIndex = new ArrayList(); //this list would keep all those indicies related to Inner loop that are consumed/used in swap.
//Making pivot node to be the secondary one, the one that needs to gain weight.
//swapping or try to swap each element of secNode to all elements of priNode.
//primary is traversed in Descending order, and secondary is traversed in ascending order.
for (int i = 0; i < secBucketCount && !bTargetAchieved; i++)
{
WeightIdPair secWIPair = (WeightIdPair)secWIPairList[i];
for (int j = priBucketCount - 1; j >= 0; j--)
{
WeightIdPair priWIPair = (WeightIdPair)priWIPairList[j];
//only move when there is a gain.
if (priWIPair.Weight > secWIPair.Weight && !usedIndex.Contains(j))
{
swapWeightGain = priWIPair.Weight - secWIPair.Weight;
movedSoFar += swapWeightGain;
if (movedSoFar <= dataToMove)
{
if (dataToMove - movedSoFar <= cushionWeight)
{
//swap the buckets and exit
secWIPairList[i] = priWIPair;
priWIPairList[j] = secWIPair;
bTargetAchieved = true;
break;
}
else
{
secWIPairList[i] = priWIPair;
priWIPairList[j] = secWIPair;
usedIndex.Add(j);
break; //i need to move fwd now
}
} //end if
else
{
if (movedSoFar - dataToMove <= cushionWeight)
{
//swap the buckets an exit
secWIPairList[i] = priWIPair;
priWIPairList[j] = secWIPair;
bTargetAchieved = true;
break;
}
else
{
movedSoFar -= swapWeightGain;
}
} //end else
} //end if for priWeight > seWeight
} //end inner for loop
} //end outer for loop
//re-assign the WeightIdPairList to respective BalanceDataForNode
priNode.WeightIdList = priWIPairList;
priNode.WeightIdList.Sort();
secNode.WeightIdList = secWIPairList;
secNode.WeightIdList.Sort();
}
} //end func.
//data to be moved from Primary node to the secondary node.
//As a result priNode and secNode got updated WeightIdPairLists.
private static void BalanceTwoNodes(BalanceDataForNode priNode, BalanceDataForNode secNode, long dataToMove)
{
int priBucketCount = priNode.ItemsCount;
int secBucketCount = secNode.ItemsCount;
ArrayList priWIPairList = priNode.WeightIdList;
ArrayList secWIPairList = secNode.WeightIdList;
int cushionFactor = 10; // 10% cushion for balancing... +- 10%
long swapWeightGain = 0; // weight gain for this swap
long cushionWeight = Convert.ToInt64(((double)(dataToMove * cushionFactor) / (double)100));
bool bTargetAchieved = false; //loop-invariant, in case we need to exit the loop in middle.
long movedSoFar = 0;
ArrayList usedIndex = new ArrayList(); //this list would keep all those indicies related to Inner loop that are consumed/used in swap.
//Making pivot node to be the secondary one, the one that needs to gain weight.
//swapping or try to swap each element of secNode to all elements of priNode.
//primary is traversed in Descending order, and secondary is traversed in ascending order.
for (int i = 0; i < secBucketCount && !bTargetAchieved; i++)
{
WeightIdPair secWIPair = (WeightIdPair)secWIPairList[i];
for (int j = priBucketCount - 1; j >= 0; j--)
{
WeightIdPair priWIPair = (WeightIdPair) priWIPairList[j];
//only move when there is a gain.
if (priWIPair.Weight > secWIPair.Weight && !usedIndex.Contains(j))
{
swapWeightGain = priWIPair.Weight - secWIPair.Weight;
movedSoFar+= swapWeightGain;
if (movedSoFar <= dataToMove)
{
if (dataToMove - movedSoFar <= cushionWeight)
{
//swap the buckets and exit
secWIPairList[i] = priWIPair;
priWIPairList[j] = secWIPair;
bTargetAchieved = true;
break;
}
else
{
secWIPairList[i] = priWIPair;
priWIPairList[j] = secWIPair;
usedIndex.Add(j);
break; //i need to move fwd now
}
} //end if
else
{
if (movedSoFar - dataToMove <= cushionWeight)
{
//swap the buckets an exit
secWIPairList[i] = priWIPair;
priWIPairList[j] = secWIPair;
bTargetAchieved = true;
break;
}
else
{
movedSoFar-=swapWeightGain;
}
} //end else
}//end if for priWeight > seWeight
}//end inner for loop
}//end outer for loop
//re-assign the WeightIdPairList to respective BalanceDataForNode
priNode.WeightIdList = priWIPairList;
priNode.WeightIdList.Sort();
secNode.WeightIdList = secWIPairList;
secNode.WeightIdList.Sort();
}
private void ApplyChangesInHashMap(BalanceDataForNode secNode)
{
ArrayList weightIdPair = secNode.WeightIdList;
Address newAddr = secNode.NodeAddress;
HashMapBucket bucket = null;
foreach (WeightIdPair widPair in weightIdPair)
{
bucket = (HashMapBucket)_hashMap[widPair.BucketId];
if (!newAddr.Equals(bucket.TempAddress))
bucket.Status = BucketStatus.NeedTransfer;
bucket.TempAddress = newAddr;
}
}
//Need to check if the source node really needs any balancing?. If the weight is more then the Avg weight/Node then its true else false.
private bool SanityCheckForCandidateNode(Address sourceNode)
{
ArrayList dataListForNodes = _nodeBalData.BalanceDataListForNodes;
foreach (BalanceDataForNode balData in dataListForNodes)
{
if (balData.NodeAddress.Equals(sourceNode))
{
if (balData.PercentData > _nodeBalData.PercentWeightPerNode)
{
this._weightToMove = balData.TotalWeight - this._nodeBalData.WeightPerNode; //Weight to move is the one that is above the Avg. weight the node Should bear.
_primaryNode = balData;
return true;
}
else
return false;
}
} //end foreach loop
return false; //nothing found.
}
