Changed EndPoint property of MongoServerInstance to a method because it sometimes does a DNS lookup and it is bad practice for properties to block.

Author: rstam

Driver/Core/MongoServerInstance.cs

@@ -46,7 +46,7 @@ public class MongoServerInstance
         private MongoServerBuildInfo _buildInfo;
         private Exception _connectException;
         private MongoConnectionPool _connectionPool;
-        private IPEndPoint _endPoint;
+        private IPEndPoint _ipEndPoint;
         private bool _isArbiter;
         private CommandResult _isMasterResult;
         private bool _isPassive;
@@ -116,24 +116,6 @@ public MongoConnectionPool ConnectionPool
             get { return _connectionPool; }
         }
 
-        /// <summary>
-        /// Gets the IP end point of this server instance.
-        /// </summary>
-        public IPEndPoint EndPoint
-        {
-            get {
-                // use a lock free algorithm because DNS lookups are rare and concurrent lookups are tolerable
-                // the intermediate variable is important to avoid race conditions
-                var endPoint = _endPoint;
-                if (endPoint == null)
-                {
-                    endPoint = _address.ToIPEndPoint(_server.Settings.AddressFamily);
-                    _endPoint = endPoint;
-                }
-                return endPoint;
-            }
-        }
-
         /// <summary>
         /// Gets whether this server instance is an arbiter instance.
         /// </summary>
@@ -215,6 +197,22 @@ public MongoServerState State
         }
 
         // public methods
+        /// <summary>
+        /// Gets the IP end point of this server instance.
+        /// </summary>
+        public IPEndPoint GetIPEndPoint()
+        {
+            // use a lock free algorithm because DNS lookups are rare and concurrent lookups are tolerable
+            // the intermediate variable is important to avoid race conditions
+            var ipEndPoint = _ipEndPoint;
+            if (ipEndPoint == null)
+            {
+                ipEndPoint = _address.ToIPEndPoint(_server.Settings.AddressFamily);
+                _ipEndPoint = ipEndPoint;
+            }
+            return ipEndPoint;
+        }
+
         /// <summary>
         /// Checks whether the server is alive (throws an exception if not).
         /// </summary>

Driver/Internal/MongoConnection.cs

@@ -354,12 +354,12 @@ internal void Open()
                 throw new InvalidOperationException("Open called more than once.");
             }
 
-            var endPoint = _serverInstance.EndPoint;
-            var tcpClient = new TcpClient(endPoint.AddressFamily);
+            var ipEndPoint = _serverInstance.GetIPEndPoint();
+            var tcpClient = new TcpClient(ipEndPoint.AddressFamily);
             tcpClient.NoDelay = true; // turn off Nagle
             tcpClient.ReceiveBufferSize = MongoDefaults.TcpReceiveBufferSize;
             tcpClient.SendBufferSize = MongoDefaults.TcpSendBufferSize;
-            tcpClient.Connect(endPoint);
+            tcpClient.Connect(ipEndPoint);
 
             _tcpClient = tcpClient;
             _state = MongoConnectionState.Open;