Configure High Availability for Micetro Central

Failover instances of Men&Mice Central can be configured to build a high availability cluster.

Note

To run Micetro in High Availability mode you must be using the MSSQL or PostgreSQL database backend for Micetro. High Availability mode is not available for other database types.

Note

When there are no HA members defined or if Micetro Central has not been configured for HA, a message will appear indicating further configuration is necessary. This documentation shows how to configure HA in the web UI for versions 10.2 and above. If you need to use the management console (thick client), please follow the documentation in [10.1](https://menandmice.com/docs/10.1/guides/implementation/central_ha)

Note

For fine-tuning the settings for the Central High Availability cluster, see Men&Mice Central HA tweaks.

Linux

  1. On the existing (or designated as primary) server running Central, edit the preferences file in /var/mmsuite/mmcentral/preferences.cfg, adding

<ClusterMemberName value="somename"/>

to the end of the file. somename is the unique name that will identify the Central instance in the high availability cluster. (E.g. “1”, “primary”, or “central1”)

  1. Restart the primary Central application:

systemctl restart mmcentral

  1. Login to the web UI as “administrator” and go to Admin then Configuration

  2. Select High Availability

  3. Type in the name of the first member server to match the name given earlier and set the priority to 10

  4. Click Add Member

../../../_images/ha-add-member.jpg

  1. Restart Central:

systemctl restart mmcentral

  1. Login to the web UI and verify that the current server is running with state “Active”

  2. Repeat steps 3-6 to add another member to the HA configuration, but now use a priority of 20 or higher

../../../_images/ha-cluster.png

  1. On the just added secondary server, install the Micetro Central application. If it’s already installed, make sure it’s stopped by using (as root):

systemctl stop mmcentral
systemctl status mmcentral

  1. Copy the /var/mmsuite/mmcentral/preferences.cfg file from the first server to the second, and change the ClusterMemberName value to match the one set up previously. Save the file and exit.

  2. Start Central on the secondary server:

systemctl start mmcentral

  1. Verify that you now have 2 servers, one primary, one secondary in the HA cluster

  2. Create a round robin DNS name for the high availability setup, i.e. two A records with the same name, but each with the IP address of the primary and secondary server respectively.

Note

Repeat these steps for each high availability failover you’d like to add. The priority for each failover member should be unique and higher than the primary.

Proceed to Server controllers.

Windows

  1. In the existing (or designated as primary) server running Central, edit the preferences file preferences.cfg, adding

<ClusterMemberName value="somename"/>

to the end of the file. somename is the unique name that will identify the Central instance in the high availability cluster. (E.g. “1”, “primary”, or “central1”)

  1. Restart the primary Central application from the command line:

mmcentral –stop
mmcentral –start

  1. Login to the web UI as “administrator” and go to Admin then Configuration

  2. Select High Availability

  3. Type in the name of the first member server to match the name given earlier and set the priority to 10

  4. Click Add Member

../../../_images/ha-add-member.jpg

  1. Restart the Central application from the command line:

mmcentral –stop
mmcentral –start

  1. Login to the web UI and verify that the current server is running with state “Active”

  2. Repeat steps 3-6 to add another member to the HA configuration, but now use a priority of 20 or higher

../../../_images/ha-cluster.png

  1. On the just added secondary server, install the Micetro Central application. If it’s already installed, make sure it’s stopped:

mmcentral –stop

  1. Copy the /var/mmsuite/mmcentral/preferences.cfg file from the first server to the second, and change the ClusterMemberName value to match the one set up previously. Save the file and exit.

  2. Start Central on the secondary server:

mmcentral –start

  1. Verify that you now have 2 servers, one primary, one secondary in Tools ‣ Manage High availability.

  2. Create a round robin DNS name for the high availability setup, i.e. two A records with the same name, but each with the IP address of the primary and secondary server respectively.

Note

Repeat these steps for each high availability failover you’d like to add. The priority for each failover member should be unique and higher than the primary.

Editing HA member options

  1. Log in to the web UI and go to Admin then Configuration

  2. Click on High Availability

  3. Hover over the server member and click on the ellipsis (or meatball) menu

  4. There are three options:

Edit Member

Change the name or priority of the server member in the HA cluster

Set Active

Set the server to be the Active member of the HA cluster manually

Remove Member

Remove the server member from the HA cluster

Proceed to Server controllers.

Updating Central in High Availability setup

Warning

The Automatic Update feature cannot be used when the Central service is in High Availability setup

The procedure for updating the Central servers in High Availability is as follows:

  1. Turn off the Central service on each secondary server

  2. Upgrade the primary server manually using an installer. An installer can be downloaded from https://download.menandmice.com/

  3. Upgrade each secondary server manually using an installer. After the upgrade finished successfully, the service will be started again.

  4. Now, both servers should be upgraded and again in High Availability mode.