Using ClusterCATS
Configuring Clusters

Load-balancing devices

You can configure ClusterCATS to work in conjunction with a third-party hardware load-balancing device or load-balancing software product to provide comprehensive load balancing and failover support for your server clusters.

This section describes the following:

• "Using Cisco LocalDirector"
• "Using third-party load-balancing devices in Windows"
• "Using third-party load-balancing devices in UNIX"

Using Cisco LocalDirector

Cisco LocalDirector is a network appliance with a secure, real-time, embedded operating system that intelligently load balances IP traffic across multiple servers. You can configure ClusterCATS to provide server availability and load information to LocalDirector using the Cisco Dynamic Feedback Protocol (DFP). LocalDirector then actively manages HTTP traffic across the cluster, based on the load information provided to it by ClusterCATS.

You can configure LocalDirector using the ClusterCATS Explorer on Windows only.

Note:   You must use Cisco LocalDirector Version 3.1.4 software or later.

Before configuring ClusterCATS with LocalDirector, you must configure LocalDirector to manage your web servers. For more information, see the Cisco documentation.

LocalDirector considerations

Be aware of the following issues when using ClusterCATS with Cisco LocalDirector:

• When load balancing with LocalDirector, ClusterCATS sets the state of each cluster member to passive mode. For more information, see "Changing active/passive settings".
• Do not use round-robin DNS.
• Turn off the ClusterCATS gradual redirection load threshold. For more information, see "Server load thresholds".
• Do not use ClusterCATS dynamic IP addressing feature. If ClusterCATS performs dynamic IP failover, the LocalDirector cannot recover the failed-over IP address. For more information, see "ClusterCATS Dynamic IP Addressing (Windows only)".
• If two or more web servers on a system are in clusters using LocalDirector load balancing, each cluster must have the same DFP Agent Listen Port number configured. The ClusterCATS DFP agent can listen only on one port.

LocalDirector dynamic-feedback command settings

Use the LocalDirector dynamic-feedback command options as described in this section to optimize your LocalDirector setup.

Note:   Do not use the dynamic-feedback-pw command. ClusterCATS does not support secure DFP hosts.

• dynamic-feedback -timeout - sets timeout to a value larger than the update frequency so LocalDirector does not prematurely terminate the connection with the cluster because of inactivity. We recommend that you set the value to at least twice the update frequency.
• dynamic-feedback -retry

  Use the dynamic-feedback -retry - sets the retry value to zero to ensure that LocalDirector continues connection attempts to the ClusterCATS DFP agent in the event of a lengthy period of system unavailability.

For more information, seeCisco's LocalDirector Command Reference.

To integrate ClusterCATS with the Cisco LocalDirector:

1. Review all considerations before continuing with this procedure.
2. Complete the LocalDirector basic hardware installation and configuration. Ensure that you have defined an IP address for LocalDirector, and that the LocalDirector network interfaces are configured correctly. You can use the ping utility to test network connectivity.
3. Create a virtual server (www.yourcompany.com) in LocalDirector that corresponds to the cluster.
4. In LocalDirector, bind explicit (real) servers participating in the cluster with the virtual server.
5. Use LocalDirector's dynamic-feedback command to specify the IP addresses of each explicit server (cluster member) and port number that each server will use to listen for DFP requests from LocalDirector. The port number must be the same as the DFP Agent Listen Port configured in step 9.

   For example:

   dynamic-feedback 192.168.64.22:9124 retry 0 attempts 30 timeout 60
   

   The DFP protocol will connect to server 192.168.64.22 at port 9124. If the connection between LocalDirector and the server is closed for any reason, LocalDirector will attempt to reconnect, every 30 seconds, indefinitely. LocalDirector will close the connection if it is inactive for 60 seconds.

   For more information, see "LocalDirector dynamic-feedback command settings".

6. Open the ClusterCATS Explorer and select a cluster.
7. Select Cluster > Properties or Configure > Administration. Both menu selections display the Cluster Properties dialog box, as the following figure shows:

   

8. Click the Load Balance tab and choose Cisco LocalDirector from the Load Balancing Product drop-down list.

   

9. Edit the cluster properties as described in the following table:

   Field	Description
   Website Alias	Enter the name of the virtual server (www.yourcompany.com) you created in step 3.
   LocalDirector IP Address	Enter the IP address of Cisco LocalDirector.
   DFP Agent Listen Port	Enter the port number on which the cluster's DFP agent should listen for incoming LocalDirector connection requests. This should be the same port specified in the LocalDirector dynamic-feedback as described in step 5.
   Update Frequency (sec)	Enter the frequency with which you want ClusterCATS to update the LocalDirector with availability data. This is typically between 5 and 30. You can enter up to 120. As you add web servers to the cluster, set a larger value. This minimizes the overhead of traffic to LocalDirector.
   HTTP Port	Enter the port number on which each cluster member listens for unsecured HTTP requests. Enter 0 if not applicable.
   HTTPS Port	Enter the port number on which each cluster member listens for secured HTTP requests. Enter 0 if not applicable.
   Bind ID	Enter the same Bind ID specified for the explicit (real) servers on the LocalDirector in step 4. For ClusterCATS/LocalDirector integration to work as intended, the server name, port number, and bind ID combination must be the same on this ClusterCATS Load Balance tab as on the LocalDirector box.

10. Click OK.

When configured, ClusterCATS automatically sets the state of each cluster member to Passive and provides the load-balancing and high availability data it acquires to LocalDirector. LocalDirector actively manages HTTP traffic across the cluster.

Using third-party load-balancing devices

Third-party load-balancing devices actively distribute load to the web servers based on packet flow while ClusterCATS monitors JRun and ColdFusion load and availability. If ClusterCATS detects that the server is becoming overloaded, it supersedes the load-balancing device and redirects traffic accordingly.

This section describes how to configure a third-party load-balancing device with ClusterCATS in the following sections:

• "Using third-party load-balancing devices in Windows"
• "Using third-party load-balancing devices in UNIX"

Using third-party load-balancing devices in Windows

To integrate ClusterCATS with a third-party load-balancing device:

1. Configure the load-balancing device or software product as recommended by the manufacturer.
2. Open the ClusterCATS Explorer and select a cluster.
3. Select Configure > Administration or right-click the cluster and select Configure > Configure. The Cluster Properties dialog box displays.
4. Click the Load Balance tab.

   

   The selection in the Load Balancing Product drop-down list indicates how ClusterCATS will actively load balance HTTP traffic across the cluster.

5. Enter the name of the website in the Website Alias field.
6. Click OK to apply your changes.

Using third-party load-balancing devices in UNIX

You cannot take advantage of ClusterCATS support of Cisco LocalDirector with ClusterCATS Web Explorer. This capability is available only in the Windows-based ClusterCATS Explorer. You can, however, configure Cisco LocalDirector as a third-party load-balancing device to work with ClusterCATS.

To integrate ClusterCATS with a third-party load-balancing device:

1. In ClusterCATS Web Explorer, click the Show Cluster link.
2. Enter the fully qualified host name of a server to integrate with another load-balancing product in the Web Server Name field.
3. Click OK.

   The Cluster Member List page appears.

4. Click the Administration link under Cluster Attributes.
5. In the Load Balancing Product field, enter the URL of the website for which the load-balancing product has been set up to manage HTTP traffic.
6. To apply your changes, click OK .

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