Using ClusterCATS
Maintaining Cluster Members

Using maintenance mode (Windows only)

Putting a ClusterCATS Server in maintenance mode lets you remove a server from an active cluster gracefully, so you can perform necessary updates or maintenance tasks without disrupting your users. Using the instructions in this section, you can take a server offline while allowing users to finish their current sessions.

Once the server is in maintenance mode, you can perform the following tasks that would normally disrupt users' experiences:

• Upgrading server software or applications
• Change content on the website
• Troubleshooting problems

When a server is in maintenance mode, inbound HTTP traffic for the affected server is redirected to the most available server in the cluster. After you complete your maintenance tasks and take the server out of maintenance mode, the servers that temporarily assumed the restricted server's IP address and HTTP traffic return the IP address to the affected server so it can receive and process HTTP requests.

Note:   Macromedia recommends that you set up your clusters with ClusterCATS dynamic IP addressing for using maintenance mode. For more information, see "Using Server Failover".

When it is enabled, maintenance performs the following:

• The Clustered Web Server on the system is set to a busy state for a user-specified period of time. New traffic to the website is redirected to another server in the cluster.
• If you are running session-aware load balancing, users who have begun sessions can continue until the ClusterCATS service is shut down.
• When the timeout period has expired, the ClusterCATS service will be shut down.
• If ClusterCATS dynamic addressing is active, the IP addresses associated with cluster members for this server will be failed over to another server, thus allowing the site to continue to function while maintenance is performed.

To put a cluster member in maintenance mode:

1. In ClusterCATS Explorer, select a cluster member to update.
2. Select Configure > Load or right-click a cluster member and select Configure > Load.

   The Properties dialog box appears for the selected cluster member with the Load tab active:

   

3. Change the peak load threshold to 0% so any additional HTTP requests will be redirected to other servers in the cluster.
4. Click OK.
5. Physically go to the server you selected in step 1 and open the ClusterCATS Server Administrator on it, by selecting Start > Programs > Macromedia > ClusterCATS Server Administrator.

   The ClusterCATS Server Administrator appears.

6. Click the BT Service Status button to display the Manage ClusterCATS Services dialog box:

   

7. Select the Stopped option to stop the ClusterCATS service, and enter a value, in minutes, in the Drain Down Period field. This option allows current users to conclude their sessions within the time indicated.
8. Click OK.

   When the drain-down period expires, the server fails over to another server in the cluster.

To take a cluster member out of maintenance mode:

1. Physically go to the server and open the ClusterCATS Server Administrator by selecting Start > Programs > Macromedia > ClusterCATS Server Administrator.

   The ClusterCATS Server Administrator appears.

2. Click the BT Service Status button to display the Manage ClusterCATS Services dialog box.
3. Select the Running option.
4. Click OK.
5. Open the ClusterCATS Explorer and select a cluster member to take out of maintenance mode.
6. Select Configure > Load or right-click a cluster member and select Configure > Load.

   The Properties dialog box appears for the selected cluster member with the Load tab active.

7. Change the peak load threshold from 0 percent to an appropriate value.
8. Click OK.

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