internal CassandraConnection Connect(Query query, IEnumerator <Host> hostsIter, List <IPAddress> triedHosts, Dictionary <IPAddress, List <Exception> > innerExceptions, out int streamId)
{
CheckDisposed();
lock (_connectionPool)
{
List <CassandraConnection> toDel = null;
foreach (var conn in _trashcan)
{
if (conn.IsEmpty())
{
_logger.Info("Connection trashed");
conn.Dispose();
if (toDel == null)
{
toDel = new List <CassandraConnection>();
}
toDel.Add(conn);
}
}
if (toDel != null)
{
foreach (var d in toDel)
{
_trashcan.Remove(d);
}
}
while (true)
{
var currentHost = hostsIter.Current;
if (currentHost == null)
{
var ex = new NoHostAvailableException(innerExceptions);
_logger.Error("All hosts are not responding.", ex);
throw ex;
}
if (currentHost.IsConsiderablyUp)
{
triedHosts.Add(currentHost.Address);
var hostDistance = _policies.LoadBalancingPolicy.Distance(currentHost);
if (!_connectionPool.ContainsKey(currentHost.Address))
{
_connectionPool.Add(currentHost.Address, new List <CassandraConnection>());
}
var pool = _connectionPool[currentHost.Address];
var poolCpy = new List <CassandraConnection>(pool);
CassandraCounters.SetConnectionsCount(currentHost.Address, poolCpy.Count);
CassandraConnection toReturn = null;
foreach (var conn in poolCpy)
{
if (!conn.IsHealthy)
{
pool.Remove(conn);
conn.Dispose();
}
else
{
if (toReturn == null)
{
if (!conn.IsBusy(_poolingOptions.GetMaxSimultaneousRequestsPerConnectionTreshold(hostDistance)))
{
toReturn = conn;
}
}
else
{
if (pool.Count > _poolingOptions.GetCoreConnectionsPerHost(hostDistance))
{
if (conn.IsFree(_poolingOptions.GetMinSimultaneousRequestsPerConnectionTreshold(hostDistance)))
{
_trashcan.Add(conn);
pool.Remove(conn);
}
}
}
}
}
if (toReturn != null)
{
streamId = toReturn.AllocateStreamId();
return(toReturn);
}
if (pool.Count < _poolingOptions.GetMaxConnectionPerHost(hostDistance) - 1)
{
bool error = false;
CassandraConnection conn = null;
do
{
Exception outExc;
conn = AllocateConnection(currentHost.Address, out outExc);
if (conn != null)
{
if (_cluster.Metadata != null)
{
_cluster.Metadata.BringUpHost(currentHost.Address, this);
}
pool.Add(conn);
}
else
{
if (!innerExceptions.ContainsKey(currentHost.Address))
{
innerExceptions.Add(currentHost.Address, new List <Exception>());
}
innerExceptions[currentHost.Address].Add(outExc);
_logger.Info("New connection attempt failed - goto another host.");
error = true;
break;
}
}while (pool.Count < _poolingOptions.GetCoreConnectionsPerHost(hostDistance));
if (!error)
{
streamId = conn.AllocateStreamId();
return(conn);
}
}
}
_logger.Verbose(string.Format("Currently tried host: {0} have all of connections busy. Switching to the next host.", currentHost.Address));
if (!hostsIter.MoveNext())
{
var ex = new NoHostAvailableException(innerExceptions);
_logger.Error("Cannot connect to any host from pool.", ex);
throw ex;
}
}
}
}
CassandraConnection AllocateConnection(IPAddress endPoint, HostDistance hostDistance, out Exception outExc)
{
CassandraConnection nconn = null;
outExc = null;
try
{
int no = 1;
if (!_allocatedConnections.TryAdd(endPoint, new AtomicValue <int>(1)))
{
AtomicValue <int> val;
_allocatedConnections.TryGetValue(endPoint, out val);
no = Interlocked.Increment(ref val.RawValue);
if (no > _poolingOptions.GetMaxConnectionPerHost(hostDistance))
{
Interlocked.Decrement(ref val.RawValue);
outExc = new ToManyConnectionsPerHost();
return(null);
}
}
RETRY:
nconn = new CassandraConnection(this, endPoint, _protocolOptions, _socketOptions, _clientOptions, _authProvider, _authInfoProvider, _binaryProtocolVersion);
var streamId = nconn.AllocateStreamId();
try
{
var options = ProcessExecuteOptions(nconn.ExecuteOptions(streamId));
}
catch (CassandraConnectionBadProtocolVersionException)
{
if (_binaryProtocolVersion == 1)
{
throw;
}
else
{
_binaryProtocolVersion = 1;
goto RETRY;
}
}
if (!string.IsNullOrEmpty(_keyspace))
{
nconn.SetKeyspace(_keyspace);
}
}
catch (Exception ex)
{
if (nconn != null)
{
nconn.Dispose();
nconn = null;
}
AtomicValue <int> val;
_allocatedConnections.TryGetValue(endPoint, out val);
Interlocked.Decrement(ref val.RawValue);
if (CassandraConnection.IsStreamRelatedException(ex))
{
HostIsDown(endPoint);
outExc = ex;
return(null);
}
else
{
throw ex;
}
}
_logger.Info("Allocated new connection");
return(nconn);
}
