Critical fix: ReconfigureAsync was incorrectly spinning up new ServerEndPoint...

Critical fix: ReconfigureAsync was incorrectly spinning up new ServerEndPoint instances after disconnect

StackExchange.Redis/StackExchange/Redis/ConnectionMultiplexer.cs

@@ -1062,8 +1062,6 @@ public void GetStatus(TextWriter log)
         internal async Task<bool> ReconfigureAsync(bool first, bool reconfigureAll, TextWriter log, EndPoint blame, string cause, bool publishReconfigure = false, CommandFlags publishReconfigureFlags = CommandFlags.None)
         {
             if (isDisposed) throw new ObjectDisposedException(ToString());
-            //if connection failed treat it as first to honor retry logic.
-            first = cause.CompareTo("connection failed") == 0 ? true : first;
             bool showStats = true;
             if (log == null)
             {

StackExchange.Redis/StackExchange/Redis/PhysicalBridge.cs

@@ -414,6 +414,10 @@ internal void OnHeartbeat(bool ifConnectedOnly)
                         var tmp = physical;
                         if (tmp != null)
                         {
+                            if(state == (int)State.ConnectedEstablished)
+                            {
+                                tmp.Bridge.ServerEndPoint.ClearUnselectable(UnselectableFlags.DidNotRespond);
+                            }
                             tmp.OnHeartbeat();
                             int writeEverySeconds = serverEndPoint.WriteEverySeconds,
                                 checkConfigSeconds = multiplexer.RawConfig.ConfigCheckSeconds;

StackExchange.Redis/StackExchange/Redis/ServerEndPoint.cs

@@ -43,7 +43,7 @@ internal sealed partial class ServerEndPoint : IDisposable
 
         private bool slaveReadOnly, isSlave;
 
-        private volatile UnselectableFlags unselectableReasons;
+        internal volatile UnselectableFlags unselectableReasons;
 
         private Version version;