//
public void SwapPrimaryReplica(String oldPrimaryUrl, String newReplicaUrl)
{
ServerPair pair = GetRowGivenPrimary(oldPrimaryUrl).GetServerPair();
pair.SetPrimary(pair.GetReplica());
pair.SetReplica(newReplicaUrl);
}
//Get endpoints
public string GetPrimaryEndpoint(int uid)
{
ServerPair pair = lookupTable.GetServerPair(uid);
if (pair == null)
{
return(null);
}
return(pair.GetPrimary());
}
public TableRow GetRowGivenReplica(String replicaUrl)
{
foreach (TableRow row in lookupTable)
{
ServerPair pair = row.GetServerPair();
if (replicaUrl.Equals(pair.GetReplica()))
{
return(row); //DEVIAMOS LANCAR EXCEPCAO CASO NAO EXISTA O MAIN SERVER.
}
}
return(null);
}
//Check if given string correspond to replica(false) or main server(true)
public bool IsPrimary(String url)
{
foreach (TableRow row in lookupTable)
{
ServerPair pair = row.GetServerPair();
if (url.Equals(pair.GetPrimary()))
{
return(true);
}
//else if (url.Equals(pair.GetReplica()))
// return false;
}
//DEVERIA SER LANCADA UMA EXCEPCAO POR NAO EXISTIR!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
return(false);
}
public TableRow(ServerPair servers, UIDRange uidRange)
{
this.servers = servers;
this.uidRange = uidRange;
}
public bool AddServer(string URL)
{
//Console.WriteLine("AddServer called");
int index = getIndex();
String primary_url = URL;
String replica_url = String.Empty;
UIDRange newUIDRange = null;
if (lookupTable.Size() == 0)
{
//Primeiro servidor
newUIDRange = lookupTable.DefaultUIDRange;
}
else
{
TableRow temp = lookupTable.GetRow(index);
string oldPrimaryUrl = temp.GetServerPair().GetPrimary();
newUIDRange = temp.GetUIDRange().Split();
replica_url = serverReplicasTable.getReplica();
IServer oldPrimaryServer = (IServer)Activator.GetObject(typeof(IServer), oldPrimaryUrl);
ulong oldPrimaryTid = oldPrimaryServer.GetMaxTID();
oldPrimaryServer.AddTIDToPendingTable(primary_url, oldPrimaryTid, newUIDRange.GetRangeStart(), newUIDRange.GetRangeEnd());
IServer newPrimaryServer = (IServer)Activator.GetObject(typeof(IServer), primary_url);
newPrimaryServer.Init(oldPrimaryTid, replica_url);
//A tabela so temos o servidor 1 e entrou um novo srvidor
//como agora temos 2 servidores, o novo servidor pode
//ser replica do servidor 1
if (lookupTable.Size() == 1)
{
//Como era o unico servidor no sistema nao tinha replica
//adiciona-mos a replica agora que entrou um segundo
//servidor, e este o que entrou (primary_url) e a replica
//do anterior
//outlink
ServerPair sp = new ServerPair(temp.GetServerPair().GetPrimary(), primary_url);
lookupTable.ReplaceRow(index, new TableRow(sp, temp.GetUIDRange()));
//inlink
serverReplicasTable.addReplicaToServer(primary_url, temp.GetServerPair().GetPrimary());
oldPrimaryServer.SetReplica(primary_url);
}
}
//outlinks
ServerPair newServerPair = new ServerPair(primary_url, replica_url);
TableRow newTableRow = new TableRow(newServerPair, newUIDRange);
lookupTable.InsertRow(index, newTableRow);
//inlinks
//primary_url e adicionado como candidato para
//ser escolhido como replica de qualquer outro
//servidor
serverReplicasTable.addPrimary(primary_url);
//Se existir replica disponivel
//replica_url e responsavel por primary_url
if (!replica_url.Equals(String.Empty))
serverReplicasTable.addReplicaToServer(replica_url, primary_url);
return true;
}
public bool AddServer(string URL)
{
//Console.WriteLine("AddServer called");
int index = getIndex();
String primary_url = URL;
String replica_url = String.Empty;
UIDRange newUIDRange = null;
if (lookupTable.Size() == 0)
{
//Primeiro servidor
newUIDRange = lookupTable.DefaultUIDRange;
}
else
{
TableRow temp = lookupTable.GetRow(index);
string oldPrimaryUrl = temp.GetServerPair().GetPrimary();
newUIDRange = temp.GetUIDRange().Split();
replica_url = serverReplicasTable.getReplica();
IServer oldPrimaryServer = (IServer)Activator.GetObject(typeof(IServer), oldPrimaryUrl);
ulong oldPrimaryTid = oldPrimaryServer.GetMaxTID();
oldPrimaryServer.AddTIDToPendingTable(primary_url, oldPrimaryTid, newUIDRange.GetRangeStart(), newUIDRange.GetRangeEnd());
IServer newPrimaryServer = (IServer)Activator.GetObject(typeof(IServer), primary_url);
newPrimaryServer.Init(oldPrimaryTid, replica_url);
//A tabela so temos o servidor 1 e entrou um novo srvidor
//como agora temos 2 servidores, o novo servidor pode
//ser replica do servidor 1
if (lookupTable.Size() == 1)
{
//Como era o unico servidor no sistema nao tinha replica
//adiciona-mos a replica agora que entrou um segundo
//servidor, e este o que entrou (primary_url) e a replica
//do anterior
//outlink
ServerPair sp = new ServerPair(temp.GetServerPair().GetPrimary(), primary_url);
lookupTable.ReplaceRow(index, new TableRow(sp, temp.GetUIDRange()));
//inlink
serverReplicasTable.addReplicaToServer(primary_url, temp.GetServerPair().GetPrimary());
oldPrimaryServer.SetReplica(primary_url);
}
}
//outlinks
ServerPair newServerPair = new ServerPair(primary_url, replica_url);
TableRow newTableRow = new TableRow(newServerPair, newUIDRange);
lookupTable.InsertRow(index, newTableRow);
//inlinks
//primary_url e adicionado como candidato para
//ser escolhido como replica de qualquer outro
//servidor
serverReplicasTable.addPrimary(primary_url);
//Se existir replica disponivel
//replica_url e responsavel por primary_url
if (!replica_url.Equals(String.Empty))
{
serverReplicasTable.addReplicaToServer(replica_url, primary_url);
}
return(true);
}
public string GetReplicaEndpoint(int uid)
{
ServerPair pair = lookupTable.GetServerPair(uid);
return(pair == null ? null : pair.GetReplica());
}
public bool RemoveServer(string url)
{
Console.WriteLine("RemoveServer");
bool isPrimary = lookupTable.IsPrimary(url);
Console.WriteLine("isPrimary: " + isPrimary);
////Falhou deve remover server e replica
//List<String> replicatedServers = serverReplicasTable.getReplicasFromServer(url);
//if (replicatedServers.Count != 0)
//{
// //NOTIFICAR DA ALTERACAO
// foreach (String replicatedServer in replicatedServers)
// {
// IServer server = (IServer)Activator.GetObject(typeof(IServer), replicatedServer);
// //AddTIDToPendingTable(string url, ulong tid, int startRange, int endRange)
// AddTIDToPendingTableAsyncDelegate remoteDel = new AddTIDToPendingTableAsyncDelegate(server.AddTIDToPendingTable);
// UIDRange primaryRange = lookupTable.GetRowGivenPrimary(replicatedServer).GetUIDRange();
// remoteDel.BeginInvoke(newReplica, server.GetMaxTID(), primaryRange.GetRangeStart(), primaryRange.GetRangeEnd(), null, null);
// }
//}
//IServer newPrimaryServer = (IServer)Activator.GetObject(typeof(IServer), newPrimary);
//AddTIDToPendingTableAsyncDelegate primaryServerDel = new AddTIDToPendingTableAsyncDelegate(newPrimaryServer.AddTIDToPendingTable);
//UIDRange newPrimaryRange = lookupTable.GetRowGivenPrimary(newPrimary).GetUIDRange();
//primaryServerDel.BeginInvoke(newReplica, newPrimaryServer.GetMaxTID(), newPrimaryRange.GetRangeStart(), newPrimaryRange.GetRangeEnd(), null, null);
//Console.WriteLine("Removeu! ");
serverReplicasTable.removeServerAndReplicas(url);
String newReplica = serverReplicasTable.getReplica();
Console.WriteLine("newReplica: " + newReplica);
String newPrimary = null;
//if the failed server is a primary server we request another replica and set replica as primary
if (isPrimary)
{
lookupTable.SwapPrimaryReplica(url, newReplica);
Console.WriteLine("swap.");
newPrimary = lookupTable.GetRowGivenReplica(newReplica).GetServerPair().GetReplica();
Console.WriteLine("newPrimary");
//if the failed server is a replica we get a new replica
}
else
{
lookupTable.SetNewReplica(url, newReplica);
//Console.WriteLine("setNewReplica.");
TableRow r = lookupTable.GetRowGivenReplica(newReplica);
Console.WriteLine(r.ToString());
ServerPair sp = r.GetServerPair();
newPrimary = sp.GetPrimary();
Console.WriteLine("newPrimary");
//LANCAR EXCEPCAO CASO HAJA FALHA
}
return(true);
//throw new NotImplementedException();
}
public TableRow(ServerPair servers, UIDRange uidRange)
{
this.servers = servers;
this.uidRange = uidRange;
}
