Merged PR 1583: Add retry logic when getting the host IP addresses after failover.

Add retry logic when getting the host IP addresses after failover.

Author: yazeng

TestSuites/FileServer/src/ServerFailover/TestSuite/FileServerFailoverBasic.cs

@@ -355,10 +355,11 @@ private void FileServerFailoverTest(string server, FileServerType fsType, bool r
                 if (fsType == FileServerType.GeneralFileServer)
                 {
                     currentAccessIpAddr = null;
-                    this.sutController.FlushDNS();
-                    IPAddress[] accessIpList = Dns.GetHostEntry(server).AddressList;
+
                     DoUntilSucceed(() =>
                     {
+                        this.sutController.FlushDNS();
+                        IPAddress[] accessIpList = Dns.GetHostEntry(server).AddressList;
                         foreach (IPAddress ipAddress in accessIpList)
                         {
                             Smb2FunctionalClient pingClient = new Smb2FunctionalClient(TestConfig.FailoverTimeout, TestConfig, BaseTestSite);
@@ -382,34 +383,38 @@ private void FileServerFailoverTest(string server, FileServerType fsType, bool r
                 else
                 {
                     currentAccessIpAddr = null;
-                    this.sutController.FlushDNS();
-                    IPAddress[] accessIpList = Dns.GetHostEntry(server).AddressList;
-                    foreach (IPAddress ipAddress in accessIpList)
+                    DoUntilSucceed(() =>
                     {
-                        if (TestConfig.IsWindowsPlatform)
+                        this.sutController.FlushDNS();
+                        IPAddress[] accessIpList = Dns.GetHostEntry(server).AddressList;
+                        foreach (IPAddress ipAddress in accessIpList)
                         {
-                            // When setting failover mode to StopNodeService for Windows, SMB2 servers on two nodes can still be accessed by the client.
-                            // So the client needs to get the new node to access it after failover by comparing host name.
-                            if (!reconnectWithoutFailover && string.Compare(currentAccessNode, Dns.GetHostEntry(ipAddress).HostName, true) == 0)
+                            if (TestConfig.IsWindowsPlatform)
                             {
-                                continue;
+                                // When setting failover mode to StopNodeService for Windows, SMB2 servers on two nodes can still be accessed by the client.
+                                // So the client needs to get the new node to access it after failover by comparing host name.
+                                if (!reconnectWithoutFailover && string.Compare(currentAccessNode, Dns.GetHostEntry(ipAddress).HostName, true) == 0)
+                                {
+                                    continue;
+                                }
                             }
-                        }
-                        Smb2FunctionalClient pingClient = new Smb2FunctionalClient(TestConfig.FailoverTimeout, TestConfig, BaseTestSite);
+                            Smb2FunctionalClient pingClient = new Smb2FunctionalClient(TestConfig.FailoverTimeout, TestConfig, BaseTestSite);
 
-                        try
-                        {
-                            pingClient.ConnectToServerOverTCP(ipAddress);
-                            pingClient.Disconnect();
-                            pingClient = null;
+                            try
+                            {
+                                pingClient.ConnectToServerOverTCP(ipAddress);
+                                pingClient.Disconnect();
+                                pingClient = null;
 
-                            currentAccessIpAddr = ipAddress;
-                            break;
-                        }
-                        catch
-                        {
+                                currentAccessIpAddr = ipAddress;
+                                return true;
+                            }
+                            catch
+                            {
+                            }
                         }
-                    }
+                        return false;
+                    }, TestConfig.FailoverTimeout, "Retry to ping to server until succeed within timeout span");
                 }
             }
             else if (witnessType == WitnessType.SwnWitness)