HTTP Monitoring Service (HTTPMon) is a resource kit utility that is included in Microsoft Windows NT 4.0 and Microsoft Windows 2000 resource kits. HTTPMon can be configured to monitor Web sites. It can also be configured to remove a node from a Network Load Balancing (NLB) or Windows Load Balancing Service (WLBS) cluster, or rejoin the node to the cluster, depending on the availability of the Web site.
NOTE: This KB article is based on HTTPMON version 3.08b from the Windows 2000 Resource Kit.
This walkthrough gives an example of how to use HTTPMon Configuration Manager. This example assumes that the NLB or WLBS cluster is configured and functioning properly, remote control is enabled, and the remote control password is configured. For this example, use the following values:
Cluster name= NLB_ClusterNOTE
Server Name= Server1, Server2
Relative Path= /
: The relative path in this case points to the default Web site.
The ports used for remote control communications are:
HTTPMon controls the WLBS NLB cluster using the remote control port and password configured in the cluster configuration. The following is the remote command that stops or starts a WLBS NLB cluster:
wlbs stop <cluster IP>:<host IP>wlbs start <cluster IP>:<host IP>
Using HTTPMon to Remove or Add a WLBS NLB Cluster
To configure HTTPMon to remove or add a WLBS NLB cluster node (based on Web site availability), follow these steps:
- Install HTTPMon on a computer that is not a member of the NLB WLBS cluster.
- On the Start menu, point to Programs, and then click HTTPMon Configuration Manager.
: HTTPMon should not be installed on a cluster node. If the computer with both the cluster node and HTTPMon becomes unavailable, you are not able to monitor using HTTPMon. Also, if you are using a single network card configuration in Unicast mode, communication between nodes is disabled. In this case, you are not able to monitor using HTTPMon, even if the Web site is available.
Monitoring a Cluster
To enable HTTPMon to monitor a cluster, follow these steps:
- Right-click Global Settings, and then click Properties.
- Under Source Server Computername, type NLB_Cluster.
- Under EnableSingleIP, click TRUE, verify that other configuration options are set to default, and then click OK.
Adding a Cluster
To enable HTTPMon to add a cluster, follow these steps:
- Right-click Web Clusters, click Add cluster..., and then click the Cluster tab.
- Under Cluster name, type NLB_Cluster.
- In the Single IP Settings section, enter the following values, and then click OK:
Virtual IP: Virtual IP
Waterlevel: leave this field blank
Adding Servers to the Cluster
To add servers to the cluster, follow these steps:
- On the Web Clusters dialog box, right-click NLB_Cluster, click Add Server..., and then click the Server tab.
- For Server name, type Server1, and then under Accessed by, enter the following values, and then click OK:
IP Address: Server1's Dedicated Network cardNOTE: The Host Name field relies on name resolution. If DNS is not in place, a Hosts file on the computer running HTTPMon may be required.
Host Name: Server1's host name.
- Repeat the preceding steps for each server in the NLB cluster.
Adding a Cluster URL
To add a cluster URL, follow these steps:
- Right-click the NLB_Cluster subfolder under Web Clusters, and then click Add URL....
- Under Friendly Name, type NLB_Cluster, and then under Relative Path, type /.
- Click Add to Cluster and Remove from Cluster to enable these features.
- On the Start menu, point to Programs, point to Administrative Tools, and then click Services.
- Click HTTP Monitoring Service to restart the service. (Restarting the service saves configuration changes.)
To verify that HTTPMon is functioning, stop either the World Wide Web Publishing service, or the Web site that is indicated in the configuration of HTTPMon on one of the NLB cluster nodes. It takes several minutes for HTTPMon to log errors in the client's event log. By default, HTTPMon tests the Web sites every 300 seconds and retries several times. For testing purposes, you may want to change configuration options to fit a particular situation.
HTTPMon logs events in the event log of the client running HTTPMon. A description of these events are included with HTTPMon documentation included in the resource kit. Event 3000 messages are listed when a cluster node is removed. Event 2000 messages are listed when a cluster node is added.