Load balancer in ManageEngine ADManager Plus

Load balancer in ADManager Plus enables you to distribute requests to instances running on other servers to optimize and provide a better AD management experience.

Things to remember

• Load balancer is only available in ADManager Plus' Professional edition.
• All the configured nodes (server) must run the same version of ADManager Plus.
• The connection between the two nodes should not be hindered by any restrictions from firewall or antivirus programs.
• One instance of ADManager Plus will act as a primary node, while all other configured nodes will be considered as secondary nodes. The secondary nodes will use the database configured in the primary node.
• Modifications to the load balancing configuration can only be made from the primary node.
• SSL certificate and session expiration time should be configured individually for each ADManager Plus node involved in the load balancing configuration.
• If you want to enable HTTPS for ADManager Plus while load balancing is enabled, make sure you enable HTTPS in all the ADManager Plus nodes involved in the load balancing configuration.
• Nodes are considered identical, so the configured nodes must be made as identical as possible. This can be done by ensuring that:
  • All the nodes have the same permissions and access to all the domains or domain controllers configured, or to be configured, in the product.
  • The time and time zone of all nodes should be the same.
  • Install the MSOnline PowerShell module if you have a Microsoft 365 account configured in ADManager Plus.
• The following features will be disabled when load balancing is enabled:
  • High availability
  • Smart card authentication

Steps to configure load balancer in ADManager Plus

1. Log in to ADManager Plus and navigate to the Admin tab.
2. In the left pane, under Enterprise Essentials, click Load Balancer.
3. In the Load Balancer With Failover page, click the Click to Configure button.
4. The Primary Server URL is auto-populated.
5. In the Secondary Server(s) section, enter the host name or IP address of the ADManager Plus instance that you would like to configure as a secondary node in the Secondary Server URL field.
6. Enter the credentials of a user account with super admin privileges in the Admin Username and Admin Password fields.
7. In the Access Mode section,
   • If you wish to configure the primary and secondary servers on different subnets:
     • Enter a virtual IP address and hostname in the Virtual IP and Virtual Hostname fields.
     • Enter a valid port number in the Load Balancer Port field and click Configure.
     • Leave the Primary and Secondary Servers are on Different Subnets checkbox unchecked.
   • If you wish to configure the servers in the same subnet:
     • Check the Primary and Secondary Servers are on Different Subnets checkbox.
     • Create a virtual host and provide the hostname in the Virtual Hostname field.
     • Enter a valid port number in the Load Balancer Port field and click Configure.
8. Click +Add New Node and repeat steps 5 and 6 to configure more secondary nodes.

Upon saving the configuration, the primary node will be automatically restarted, followed by the secondary node(s).

Note: If the primary node goes down, traffic is automatically redirected to the secondary node. When the primary node is restored, users can manually promote it back to its primary role by restarting the secondary node.

Steps to modify load balancer configuration

As mentioned earlier, modifications to the load balancing configuration must be made only from the instance configured as the primary node.

To modify a server,

1. Log in to ADManager Plus' primary node.
2. Navigate to the Admin tab, and under Enterprise Essentials, click Load Balancer.
3. In the Load Balancer With Failover window, click the Edit button to modify configurations like host name, port number, etc.
4. Click the x icon to remove a node from the setup.
5. Click Save.

Note: You can delete the entire load balancing setup by clicking the Remove button in the Load Balancer With Failover window.

Steps to manage scheduled jobs

Scheduled jobs such as automation, report generation, database backup, etc., are run from the primary node by default. However, you can also run them from a secondary node and reduce the load on the primary node using the Manage Scheduled Jobs option.

To achieve this,

1. Log in to ADManager Plus' primary node.
2. Navigate to the Admin tab, and under Enterprise Essentials, click Load Balancer.
3. In the Load Balancer With Failover window, click the Manager Scheduled Jobs option at the top-right corner.
4. In the Run Scheduled Jobs On drop-down, select the preferred node to handle scheduled jobs.
5. In the Failover for Scheduled Jobs drop-down, choose the failover node where scheduled job s should run when the primary node goes down.
6. Click Save and restart the server.

Troubleshooting tips

1. Build number is different from the primary node.

Cause: This error will occur when the build number of the ADManager Plus instance configured as the secondary node is different from the build number of the primary node in the Load Balancing Configuration.

Solution: Make sure you update all the ADManager Plus instances configured as secondary nodes to match the build number of the ADManager Plus instance configured as the primary node. Refer to the Service Pack page to learn how to update ADManager Plus.

2. Scheduled jobs are not running. Please restart this server.

Cause: Once you modify the Manage Scheduled Jobs setting and choose a new server to run the scheduled jobs, you must restart the selected node. If the node is not restarted, this error will occur.

Solution: Restart the node to run the scheduled jobs.

3. Protocol mismatch found. Make sure all the nodes involved in load balancing use the same protocol.

Cause: This error will occur if a secondary server uses a different protocol than the one used in the primary node.

Solution: All secondary nodes involved in the load balancing configuration must use the same protocol used by the primary node. For example, if HTTPS is enabled in the primary node, you must enable HTTPS in all secondary nodes as well.

4. Communication issue. Make sure the port 7800 is not blocked by the firewall in both the primary and secondary nodes. If the problem persists, click here to troubleshoot.

Cause:

• There might be a network connection issue between the primary and secondary nodes.
• The load balancer service in the primary node will run on a port that is different from the port used by ADManager Plus. By default, the load balancer service is assigned to port 7800. If port 7800 is already in use, port 7801 will be assigned. If it is unavailable, port 7802 will be assigned, and so on. This error will occur if the default port assigned to the load balancer service is blocked by the firewall.

Solution:

• Try to ping the secondary node from the primary node and check if there is a connection issue.
• Check if the port 7800 is open and available in both primary and secondary nodes. If it is available, make sure the port is not blocked by the firewall in both the primary and secondary servers. If port 7800 is not available, try port 7801, then port 7802, and so on.

5. A node is unreachable.

Cause: This error could occur due to any of the following reasons:

• The node is down.
• There is a change in the IP address of the node.
• There is a communication error between the primary node and the problematic node.

Solution: Restart the node and check whether the issue is resolved. Also, ensure that the primary and the problematic node can communicate with each other without any hassle.

6. Error in starting the secondary node after removing it from the load balancing configuration.

Cause: This error could error occur if the node was removed when it was down or unreachable.

Solution: Navigate to <Installation Directory>\ADManager Plus\bin folder in the secondary node that you had removed from the cluster, and execute the RemoveClusterSetup.bat before starting the node.