Windows Server 2003 : Using Network Load Balancing (part 2) - Deploying a Network Load Balancing Cluster & Monitoring Network Load Balancing

Deploying a Network Load Balancing Cluster

Once you have planned the network infrastructure for your NLB cluster and decided on the operational mode, you can plan the actual deployment process. The basic steps in deploying NLB for a cluster of Web servers on a perimeter network are as follows:

Monitoring Network Load Balancing

Once you have created and configured your Network Load Balancing cluster, several tools included in Windows Server 2003 can be used to monitor the cluster’s ongoing processes.

Using Network Load Balancing Manager

When you display the Network Load Balancing Manager application, the bottom pane of the window displays the most recent log entries generated by activities in the NLB Manager (see Figure 3). These entries detail any configuration changes and contain any error messages generated by improper configuration parameters on any host in the cluster.

Figure 3. The Network Load Balancing Manager’s log pane

By default, the log entries that Network Load Balancing Manager displays are not saved. To save a continuing log, you must enable logging by selecting Log Settings from the NLB Manager’s Options menu. In the Log Settings dialog box, select the Enable Logging check box, and then, in the Log Filename text box, specify the name you want to use for the log file. The NLB Manager creates the file in the Documents And Settings folder’s subfolder named for the account used to log on to the server.

Using Event Viewer

The Network Load Balancing Manager’s log pane and log file contain information only about the NLB Manager’s activities. To display log information about the Network Load Balancing service, you must look at the System log in the Event Viewer console, as shown in Figure 4. Entries concerning the Network Load Balancing service are labeled WLBS. (This stands for Windows Load Balancing Service, a holdover from the Windows NT name for the service.)

Figure 4. Windows Server 2003 Event Viewer

Using Nlb.exe

You can control many of an NLB cluster’s functions from the Windows Server 2003 command line using a utility called Nlb.exe. Some of the program’s most useful parameters are as follows:

• display Displays the configuration parameters stored in the registry for a specific cluster, plus the most recent cluster-related System log entries, the computer’s IP configuration, and the cluster’s current status.

• drain port Prevents a specified cluster from handling any new traffic conforming to the rule containing the port specified by the port variable.

• drainstop Disables all cluster traffic handling after completing the transactions currently in process.

• params Displays all the current configuration parameters for a specified cluster on the local host, as follows:

  WLBS Cluster Control Utility V2.4 (c) 1997-2003 Microsoft Corporation.
  Cluster 192.168.2.101
  Retrieving parameters
  Current time              = 3/19/2003 1:55:24 AM
  HostName                  = cz3net.int.adatum.com
  ParametersVersion         = 4
  CurrentVersion            = 00000204
  EffectiveVersion          = 00000201
  InstallDate               = 3E779B7C
  HostPriority              = 3
  ClusterIPAddress          = 192.168.2.101
  ClusterNetworkMask        = 255.255.255.0
  DedicatedIPAddress        = 192.168.2.3
  DedicatedNetworkMask      = 255.255.255.0
  McastIPAddress            = 0.0.0.0
  ClusterName               = www.int.adatum.com
  ClusterNetworkAddress     = 03-bf-c0-a8-02-65
  IPToMACEnable             = ENABLED
  MulticastSupportEnable    = ENABLED
  IGMPSupport               = DISABLED
  MulticastARPEnable        = ENABLED
  MaskSourceMAC             = ENABLED
  AliveMsgPeriod            = 1000
  AliveMsgTolerance         = 5
  NumActions                = 100
  NumPackets                = 200
  NumAliveMsgs              = 66
  DescriptorsPerAlloc       = 512
  MaxDescriptorAllocs       = 512
  TCPConnectionTimeout      = 60
  IPSecConnectionTimeout    = 86400
  FilterICMP                = DISABLED
  ClusterModeOnStart        = STARTED
  HostState                 = STARTED
  PersistedStates           = NONE
  ScaleSingleClient         = DISABLED
  NBTSupportEnable          = ENABLED
  NetmonAliveMsgs           = DISABLED
  IPChangeDelay             = 60000
  ConnectionCleanupDelay    = 300000
  RemoteControlEnabled      = ENABLED
  RemoteControlUDPPort      = 2504
  RemoteControlCode         = 00000000
  RemoteMaintenanceEnabled  = 00000000
  BDATeaming                = NO
  TeamID                    =
  Master                    = NO
  ReverseHash               = NO
  IdentityHeartbeatPeriod   = 10000
  IdentityHeartbeatEnabled  = ENABLED
  
  
  PortRules (1):
        VIP      Start  End   Prot   Mode   Pri Load Affinity
  --------------- ----- ----- ---- -------- --- ---- --------
  All               80    80  TCP  Multiple      Eql None
  Statistics:
  Number of active connections   = 0
  Number of descriptors allocated= 0
  
  
  					  

• query Displays the current state of all hosts in a specified cluster, as follows:

  WLBS Cluster Control Utility V2.4 (c) 1997-2003 Microsoft Corporation.
  Cluster 192.168.2.101
  Host 3 has entered a converging state 3 time(s) since joining the cluster
    and the last convergence completed at approximately: 3/19/2003 12:06:20 AM
  Host 3 converged with the following host(s) as part of the cluster:
  1, 3
  
  
  					  

• queryport port Displays the current status of the rule containing the port specified by the port variable, as follows:

  WLBS Cluster Control Utility V2.4 (c) 1997-2003 Microsoft Corporation.
  Cluster 192.168.2.101
  Retrieving state for port rule 80
  Rule is enabled
  Packets: Accepted=0, Dropped=17