Auto-scaling Gitaly and Praefect

Team,

A customer has reached out to us asking the following about auto-scaling and it was suggested I open an issue here to discuss. As I understand it, auto-scaling is not supported at the moment but I was hoping the team could answer this customers questions and provide us with a better idea of when this capability will be available.

We are configuring Praefect in our gitlab cluster and based on the documentation provided on https://docs.gitlab.com/ee/administration/gitaly/praefect.htm the following configuration block should specify Gitaly backend s to use on praefect:

praefect[‘virtual_storages’] = {
  ‘default’ => {
    ‘gitaly-1’ => {
      ‘address’ => ‘tcp://GITALY_HOST:8075’,
      ‘token’   => ‘PRAEFECT_INTERNAL_TOKEN’,
      ‘primary’ => true
    },
    ‘gitaly-2’ => {
      ‘address’ => ‘tcp://GITALY_HOST:8075’,
      ‘token’   => ‘PRAEFECT_INTERNAL_TOKEN’
    },
    ‘gitaly-3’ => {
      ‘address’ => ‘tcp://GITALY_HOST:8075’,
      ‘token’   => ‘PRAEFECT_INTERNAL_TOKEN’
    }
  }
}

We have an auto scaling group for Gitaly nodes, so I was wondering how is the configuration updated in case a node goes down and aws starts a new node? If another node is started does it needs to be synchronized when the node starts, since any new node would by out of sync with the primary. Is there a rake task that would provide us the node that is configured as primary using sql consensus?

Any help you can give is appreciated.