public void PerformShutdownMove()
{
//targetnode is the one which comes next in the circle, effectively returned by GetObjectLocation
Node targetNode = _nodeResolver.GetObjectLocation(TcpHelper.SelfIPAddress.ToString());
//is targetnode self? (am I the only node in the circle?)
if (targetNode.EndPoint.ToString().CompareTo(TcpHelper.SelfIPAddress.ToString()) == 0)
{
return;
}
string endPoint = string.Format("net.tcp://{0}:{1}/HoCCacheService", targetNode.EndPoint.ToString(), targetNode.ServicePort);
CacheServiceReference.CacheServiceClient nodeService = new CacheServiceReference.CacheServiceClient(new NetTcpBinding(SecurityMode.None), new EndpointAddress(endPoint));
Node self = new Node()
{
EndPoint = TcpHelper.SelfIPAddress, NodeState = NodeState.Active
};
//move the objects to the nearest node async
Parallel.ForEach <KeyValuePair <string, ServerCacheItem> >(_cache, valuePair =>
{
nodeService.DoInterNodeObjectTransfer(self, valuePair.Key, valuePair.Value);
valuePair.Value.ItemState = CacheItemState.Moved;
valuePair.Value.RelocatedTo = targetNode;
});
}
public void MoveObjectCallBack(object state)
{
Node targetNode = (Node)state;
string nodeKeyHash = Hasher.GetHash(targetNode.EndPoint.ToString());
string previousNodeHash = Hasher.GetHash(_nodeResolver.GetPreviousItemInCircle(targetNode.EndPoint.ToString()));
//if self is B, typical scenarios -> A-newnode-MID-B, MID-A-newnode-B-C
//A being the previous node, B being the current node and newnode being the new node.
string lowerBound = previousNodeHash;
string upperBound = nodeKeyHash;
IEnumerable <KeyValuePair <string, ServerCacheItem> > candidateList = _cache.Where <KeyValuePair <string, ServerCacheItem> >(x =>
((x.Value.Hash.CompareTo(upperBound) < 0) &&
(x.Value.Hash.CompareTo(lowerBound) > 0)));
//special case: A-MID-newnode-B
if (lowerBound.CompareTo(upperBound) > 0)
{
candidateList = _cache.Where <KeyValuePair <string, ServerCacheItem> >(x =>
((x.Value.Hash.CompareTo(upperBound) < 0) ||
(x.Value.Hash.CompareTo(lowerBound) > 0)));
}
if (candidateList.Count() == 0)
{
return;
}
Node self = new Node()
{
EndPoint = TcpHelper.SelfIPAddress, NodeState = NodeState.Active
};
//prepare the connection
string endPoint = string.Format("net.tcp://{0}:{1}/HoCCacheService", targetNode.EndPoint.ToString(), targetNode.ServicePort);
CacheServiceReference.CacheServiceClient nodeService = new CacheServiceReference.CacheServiceClient(new NetTcpBinding(SecurityMode.None), new EndpointAddress(endPoint));
try
{
//move each of the object to the other node async
foreach (KeyValuePair <string, ServerCacheItem> valuePair in candidateList)
{
nodeService.DoInterNodeObjectTransfer(self, valuePair.Key, valuePair.Value);
valuePair.Value.ItemState = CacheItemState.Moved;
valuePair.Value.RelocatedTo = targetNode;
}
;
nodeService.EndInterNodeObjectTransfer(self);
Thread.Sleep(2000);//wait the current thread - note that this is not the main thread
RemoveOrResetMovedItems(targetNode);
//note that any object update that happens during this time is handled by the CacheService.
//basically it copies the update to the new node too.
}
catch
{
ResetMovedObjectState(); //in case of any issues revert back to normal state.
}
}
public void StoreCacheItem(string key, ClientCacheItem value)
{
ServerCacheItem cacheItemWrapped;
if (!_localCache.TryGetValue(key, out cacheItemWrapped))
{
cacheItemWrapped = new ServerCacheItem()
{
ItemState = CacheItemState.None
}
}
;
cacheItemWrapped.Hash = Hasher.GetHash(key);
cacheItemWrapped.Value = value;
Func <string, ServerCacheItem, ServerCacheItem> updateValueFactory = ((x, y) => (cacheItemWrapped));
_localCache.AddOrUpdate(key, cacheItemWrapped, updateValueFactory);
//has the item been moved to another node?
if (cacheItemWrapped.ItemState == CacheItemState.Moved)
{
Debug.Assert(cacheItemWrapped.RelocatedTo != null);
Node self = new Node()
{
EndPoint = TcpHelper.SelfIPAddress, NodeState = NodeState.Active
};
//prepare the connection
string endPoint = string.Format("net.tcp://{0}:{1}/HoCCacheService", cacheItemWrapped.RelocatedTo.EndPoint.ToString(), cacheItemWrapped.RelocatedTo.ServicePort);
CacheServiceReference.CacheServiceClient nodeService = new CacheServiceReference.CacheServiceClient(new NetTcpBinding(SecurityMode.None), new EndpointAddress(endPoint));
//update to the target node.
nodeService.StoreCacheItem(key, value);
}
}
