class Puma::Cluster

def stats

@!attribute [r] stats
the master process.
Inside of a child process, this will return all zeroes, as @workers is only populated in 
def stats
  old_worker_count = @workers.count { |w| w.phase != @phase }
  worker_status = @workers.map do |w|
    {
      started_at: utc_iso8601(w.started_at),
      pid: w.pid,
      index: w.index,
      phase: w.phase,
      booted: w.booted?,
      last_checkin: utc_iso8601(w.last_checkin),
      last_status: w.last_status,
    }
  end
  {
    started_at: utc_iso8601(@started_at),
    workers: @workers.size,
    phase: @phase,
    booted_workers: worker_status.count { |w| w[:booted] },
    old_workers: old_worker_count,
    worker_status: worker_status,
  }.merge(super)
end