Add Agent server to cluster

A typical installation includes only one BEP Agent instance. You can add more instances and combine them into a cluster without configuring Control Tower additionally.

Meet prerequisites

Comply with the following prerequisites:

• The Master server is installed.

• The primary Agent server is installed.

• The new Agent server is prepared and configured exactly as the primary Agent.

• The new Agent's domain name is included in SAN or valid wildcard certificates. For that, use the command:

  openssl x509 -in server.crt -text -noout | grep -A4 'Subject Alternative Name'

• A new DNS alias is created for the new Agent servers.

• The existing /vds-data directory is mounted to the new Agent server.

Install and configure

The main idea is to add the BEP Agent Worker component by installing the full Agent component pointing to the existing Master server.

1. On the new Agent server, run the following commands to install the components:

   $ ./install.sh install agent -c local --limit <NEW_AGENT_HOST> #install
   $ ./install.sh check agent -c local --limit <NEW_AGENT_HOST> #check

2. Make sure that config.yml has not been changed since the initial installation.

3. If you've changed mesos-agent.ini (for example, its --resources part), update the configuration after the installation:

   1. Log in to the new Agent server via SSH.
   2. Manually add the same changes to INSTALL_DIR/supervisord/apps/mesos-agent.ini.
   3. Run wfmanager update mesos-agent to update the configuration.

Check installation

To verify that the installation of the new Agent is successful, follow the steps below:

1. Ensure that the Worker process is started without errors. For that, check INSTALL_DIR/logs/mesos-agent.log for the statuses of the connections to the MASTER nodes.
2. Check that the new Agent servers are visible in the Mesos administrator console.
3. Perform the out-of-the-box Business Process check to ensure that the new server takes requests and the processes run without errors.