public override void execute(MetaDataServer md)
{
Console.WriteLine("#MDS: Registering DS " + DataServerId);
if ( md.DataServers.ContainsKey(DataServerId) )
{
md.DataServers.Remove(DataServerId);
}
ServerObjectWrapper remoteObjectWrapper = new ServerObjectWrapper(DataServerPort, DataServerId, DataServerHost);
md.DataServers.Add(DataServerId, remoteObjectWrapper);
md.addServerToUnbalancedFiles(DataServerId);
HeartbeatMessage heartbeat = new HeartbeatMessage(DataServerId, 0 , 0, 0, 0, new Dictionary<string,FileAccessCounter>());
md.receiveHeartbeat(heartbeat);
md.makeCheckpoint();
}
void sendHeartbeat(object source, ElapsedEventArgs e)
{
HeartbeatMessage heartbeat = new HeartbeatMessage(Id, Files.Count, ReadCounter, ReadVersionCounter, WriteCounter, AccessCounter);
Task[] tasks = new Task[MetaInformationReader.Instance.MetaDataServers.Count];
for (int md = 0; md < MetaInformationReader.Instance.MetaDataServers.Count; md++)
{
IMetaDataServer metadataServer = MetaInformationReader.Instance.MetaDataServers[md].getObject<IMetaDataServer>();
tasks[md] = Task.Factory.StartNew(() => { metadataServer.receiveHeartbeat(heartbeat); });
}
Task.WaitAll(tasks);
ReadCounter = 0;
ReadVersionCounter = 0;
WriteCounter = 0;
}
public void receiveHeartbeat(HeartbeatMessage heartbeat)
{
string serverID = heartbeat.ServerId;
if (!Heartbeats.ContainsKey(serverID))
{
Heartbeats.Add(serverID, new Queue<HeartbeatMessage>());
}
if (Heartbeats[serverID].Count == MAX_HEARTBEATS)
{
Heartbeats[serverID].Dequeue();
}
Heartbeats[serverID].Enqueue(heartbeat);
Dictionary<string, FileAccessCounter> heartbeatAccesses = heartbeat.AccessCounter;
foreach (KeyValuePair<string, FileAccessCounter> entry in heartbeatAccesses)
{
addAccesses(serverID, entry.Key, entry.Value);
if (entry.Value.WriteCounter > 0)
{
unregisterMigratingFile(entry.Value.FileName, serverID);
}
}
double avg = calculateAverageLoad();
double serverLoad = calculateServerLoad(serverID);
if ((serverLoad > 1) && (serverLoad > (avg * OVERLOAD_MULTIPLIER)))
{
//migration:
Console.WriteLine("#MDS: Server " + serverID + " in overloaded state!");
List<FileMetadata> closedFiles = getClosedFiles(serverID);
Console.WriteLine("\tFiles to move: " + closedFiles.Count);
List<ServerObjectWrapper> servers = getSortedServers(DataServers.Count);
string filename = getMostAccessedFile(closedFiles).FileName;
List<ServerObjectWrapper> cleanServers = getUnderLoadServersWithoutFile(servers, avg, filename);
Console.Write("\tServers available: " + cleanServers.Count + "\r\n\t[ ");
foreach (ServerObjectWrapper srv in cleanServers)
{
Console.WriteLine(srv.Id + " ");
}
Console.WriteLine("]");
if (cleanServers.Count != 0)
{
executeOperation(new MetaDataMigrateOperation(serverID, cleanServers[0].Id, filename));
}
}
}
