Setting Hostnames

March 26, 2020 Contributors

You must set up system hostnames in a manner that is consistent with Momentum; however, this can be difficult to do in an Amazon Web Services (AWS) environment.

Momentum’s installation requires that each node is able to resolve its own hostname (e.g., the value of $HOSTNAME), as well as the hostnames of all nodes in the cluster. We recommend you use fully qualified domain names (FQDNs) for these hostnames.

Warning

Failure to use consistent and well-resolved hostnames will result in various installation problems and errors.

Run the following commands if your current hostnames are not FQDNs and do not resolve cleanly.

Note

The following solution is run using basic tools, but you may want to use advanced solutions such as Puppet and cloud-config.

  1. Change the output of hostname.

    hostname hostname -f

  2. Manually edit the /etc/sysconfig/network file so its HOSTNAME field matches the output of hostname -f.

    NETWORKING=yes
    HOSTNAME='mymta1.localnet.example.com'
    
  3. Reboot the system. You may also choose to do this:

    source /etc/sysconfig/network

  4. Confirm your new hostname resolves successfully.

    dig +short $HOSTNAME

  5. Either edit the /etc/hosts file on all systems in the cluster to match this convention or configure your Domain Name Server accordingly.