Method: Synapse::ServiceWatcher::BaseWatcher#backends

Defined in:
lib/synapse/service_watcher/base.rb

#backends ⇒ Object 



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# File 'lib/synapse/service_watcher/base.rb', line 82

def backends
  filtered = backends_filtered_by_labels

  if @leader_election
    failure_warning = nil
    if filtered.empty?
      failure_warning = "synapse: service #{@name}: leader election failed: no backends to choose from"
    end

    all_backends_have_ids = filtered.all?{|b| b.key?('id') && b['id']}
    unless all_backends_have_ids
      failure_warning = "synapse: service #{@name}: leader election failed; not all backends include an id"
    end

    # no problems encountered, lets do the leader election
    if failure_warning.nil?
      smallest = filtered.sort_by{ |b| b['id']}.first
      log.debug "synapse: leader election chose one of #{filtered.count} backends " \
        "(#{smallest['host']}:#{smallest['port']} with id #{smallest['id']})"

      return [smallest]

    # we had some sort of problem, lets log about it
    elsif (Time.now - @leader_last_warn) > LEADER_WARN_INTERVAL
      @leader_last_warn = Time.now
      log.warn failure_warning
      return []
    end
  end

  return filtered
end