MDaemon Clustering - Deployment Requirements and How to Configure Nodes - Knowledgebase (2023)

MDaemon's clustering service is designed to share its configuration between two or more MDaemon servers on your network.

Clustering allows you to use load balancing hardware or software to distribute your email load across multiple MDaemon servers, which can improve speed and efficiency by reducing network congestion and overhead and maximizing your email resources. mail. It also helps ensure redundancy in your email systems if one of your servers suffers a hardware or software failure.

MDaemon version 20.0.0 includes support for configuring MDaemon on clusters of nodes. MDaemon versions 19.5 and later do not support grouping.

1. An MDaemon cluster will have a primary node and a secondary node. One MDaemon server will be set as Primary and all others will be Secondary.
   1. The primary node is the only node that can be used to make configuration changes. If you make configuration changes on secondary servers, they will be overwritten. Most of the UI on secondary servers has been disabled.
   2. The XML API on child nodes is read-only.
   3. Email changes that occur on child nodes are sent to the master node, and the master node notifies all other nodes of the change.
2. Each node in the cluster requires its own unique MDaemon key.
3. MDaemon does not handle the routing of any traffic. A third-party load balancer is recommended to manage traffic routing.
   • This is very important for Webmail and Remote Administration (MDRA) traffic as they are cluster aware. Session information for Webmail and MDRA is not passed between nodes. When you connect to Webmail or MDRA on a specific server, all traffic for that session must be routed to that server.
   • Persistent sessions must be enabled on the load balancer so that all traffic from the same IP is routed to the same host.
4. All HTTP and XMPP traffic must be routed to the master node. This is the easiest and least confusing method. There are many reasons for this. If you are not using the items listed below, you can configure them however you like. Fixed sessions are still required.
   • The XMPP server is not cluster aware. If you use chat features, all XMPP traffic must go to the same server.
   • MDRA is not cluster aware. If the MDRA is routed to a secondary server, the changes will be logged. MDRA traffic must be routed to the primary node.
   • Webmail traffic must be routed to the same server as XMPP traffic, otherwise the Webmail IM feature will not work.
5. Mailboxes must be stored on a shared path accessible from all cluster nodes. If you use a UNC path, the MDaemon service must run as a user who has access to the network location.
   
   • It is a manual process to move mailbox contents and update mailbox paths in MDaemon.
   • The new account template will be updated with the mailbox path provided in the grouping settings
6. Public folders must be stored in a shared path accessible from all cluster nodes.
   • It is a manual process to move the data to the shared location.
   • The Cluster service will update the MDaemon.ini file with the public folder path provided in the Clustering settings.
7. Every node in the cluster must be on the same network. We do not recommend using this to aggregate servers located in different locations.
8. Each node in the cluster must be running the same version of MDaemon.
9. Dynamic classification sends all requests to the primary server and data from the primary server is replicated to the secondary servers.
   • If the primary is offline, the secondary servers use their own dynamic display settings, which must be identical to the primary's configuration at the time it was taken offline. When the primary comes back online, all DS changes made by the secondary servers will be logged.
   • If the principal fails, there may be problems trying to unfreeze an email account that was frozen while the principal was offline.
10. Each node is expected to have the correct certificates installed. Certificates must be manually moved to each node in the cluster.
    • LetsEncrypt has not been updated to handle child nodes at this time.
11. The Lockfiles directory must be a shared location. The Clustering Service can do this automatically. For manual configuration, edit the path to the LockFiles= key in the [Directories] section of the \MDaemon\App\MDaemon.ini file.
12. The \MDaemon\PEM directory must be a shared location. Edit the PEM key in the [Directories] section of the \MDaemon\App\MDaemon.ini file. Copy the MDaemon\PEM\ folder to the new shared location and restart MDaemon.
13. Attachment connection cannot be used on a cluster. If enabled, all attachments exported from secondary servers will be inaccessible and orphaned.
14. All nodes in a cluster must be configured to use the same time zone and the times must be the same. If the time zone is not the same or if the times are off by more than 1 second, a warning will be logged in the cluster log.

Configuring the Cluster Service

Follow these steps to configure the Cluster service:

1. Be sure to update all mailbox paths and adjust public folder paths. The master server must be using a network storage location for this data and must be able to access the data without any problems before proceeding.
2. All appropriate certificates must be installed on each node.
3. Install MDaemon on a secondary node using a unique key.
4. On the master node, go to Configuration > Cluster Service.
5. Select Enable Cluster Service
6. Right-click the Registered Servers list and click Add New MDaemon Server to Cluster
   - This can be slow because it searches the network for available servers.
7. In Server Name, enter the NETBIOS name, IP address or DNS name of the secondary node where MDaemon is installed or select the server from the drop-down list — there may be a delay while it searches the network for available servers.
8. Click OK.
9. Check the Plugins/Cluster log to make sure the two servers have connected and replication is happening.
10. Go to Configuration > Cluster Service on the secondary node to confirm that it now also lists the primary and secondary nodes under Registered Servers.
11. Configure the load balancer hardware or software to route traffic to the cluster as discussed above.