diff --git a/lib/vmpooler/metrics.rb b/lib/vmpooler/metrics.rb
index 241dc18..98c17f9 100644
--- a/lib/vmpooler/metrics.rb
+++ b/lib/vmpooler/metrics.rb
@@ -1,24 +1,24 @@
 # frozen_string_literal: true
 
+require 'vmpooler/metrics/statsd'
+require 'vmpooler/metrics/graphite'
+require 'vmpooler/metrics/promstats'
+require 'vmpooler/metrics/dummy_statsd'
+
 module Vmpooler
   class Metrics
     # static class instantiate appropriate metrics object.
     def self.init(logger, params)
       if params[:statsd]
-        metrics = Vmpooler::Statsd.new(logger, params[:statsd])
+        metrics = Vmpooler::Metrics::Statsd.new(logger, params[:statsd])
       elsif params[:graphite]
-        metrics = Vmpooler::Graphite.new(logger, params[:graphite])
+        metrics = Vmpooler::Metrics::Graphite.new(logger, params[:graphite])
       elsif params[:prometheus]
-        metrics = Vmpooler::Promstats.new(logger, params[:prometheus])
+        metrics = Vmpooler::Metrics::Promstats.new(logger, params[:prometheus])
       else
-        metrics = Vmpooler::DummyStatsd.new
+        metrics = Vmpooler::Metrics::DummyStatsd.new
       end
       metrics
     end
   end
 end
-
-require 'vmpooler/metrics/statsd'
-require 'vmpooler/metrics/dummy_statsd'
-require 'vmpooler/metrics/graphite'
-require 'vmpooler/metrics/promstats'
diff --git a/lib/vmpooler/metrics/dummy_statsd.rb b/lib/vmpooler/metrics/dummy_statsd.rb
index 2cc4ac6..96f2eaa 100644
--- a/lib/vmpooler/metrics/dummy_statsd.rb
+++ b/lib/vmpooler/metrics/dummy_statsd.rb
@@ -1,22 +1,24 @@
 # frozen_string_literal: true
 
 module Vmpooler
-  class DummyStatsd < Metrics
-    attr_reader :server, :port, :prefix
+  class Metrics
+    class DummyStatsd < Metrics
+      attr_reader :server, :port, :prefix
 
-    def initialize(*)
-    end
+      def initialize(*)
+      end
 
-    def increment(*)
-      true
-    end
+      def increment(*)
+        true
+      end
 
-    def gauge(*)
-      true
-    end
+      def gauge(*)
+        true
+      end
 
-    def timing(*)
-      true
+      def timing(*)
+        true
+      end
     end
   end
 end
diff --git a/lib/vmpooler/metrics/graphite.rb b/lib/vmpooler/metrics/graphite.rb
index e94e77a..128805d 100644
--- a/lib/vmpooler/metrics/graphite.rb
+++ b/lib/vmpooler/metrics/graphite.rb
@@ -3,43 +3,45 @@
 require 'rubygems' unless defined?(Gem)
 
 module Vmpooler
-  class Graphite < Metrics
-    attr_reader :server, :port, :prefix
+  class Metrics
+    class Graphite < Metrics
+      attr_reader :server, :port, :prefix
 
-    def initialize(logger, params = {})
-      raise ArgumentError, "Graphite server is required. Config: #{params.inspect}" if params['server'].nil? || params['server'].empty?
+      def initialize(logger, params = {})
+        raise ArgumentError, "Graphite server is required. Config: #{params.inspect}" if params['server'].nil? || params['server'].empty?
 
-      @server = params['server']
-      @port   = params['port'] || 2003
-      @prefix = params['prefix'] || 'vmpooler'
-      @logger = logger
-    end
-
-    def increment(label)
-      log label, 1
-    end
-
-    def gauge(label, value)
-      log label, value
-    end
-
-    def timing(label, duration)
-      log label, duration
-    end
-
-    def log(path, value)
-      Thread.new do
-        socket = TCPSocket.new(server, port)
-        begin
-          socket.puts "#{prefix}.#{path} #{value} #{Time.now.to_i}"
-        ensure
-          socket.close
-        end
+        @server = params['server']
+        @port   = params['port'] || 2003
+        @prefix = params['prefix'] || 'vmpooler'
+        @logger = logger
+      end
+
+      def increment(label)
+        log label, 1
+      end
+
+      def gauge(label, value)
+        log label, value
+      end
+
+      def timing(label, duration)
+        log label, duration
+      end
+
+      def log(path, value)
+        Thread.new do
+          socket = TCPSocket.new(server, port)
+          begin
+            socket.puts "#{prefix}.#{path} #{value} #{Time.now.to_i}"
+          ensure
+            socket.close
+          end
+        end
+      rescue Errno::EADDRNOTAVAIL => e
+        warn "Could not assign address to graphite server #{server}: #{e}"
+      rescue StandardError => e
+        @logger.log('s', "[!] Failure logging #{path} to graphite server [#{server}:#{port}]: #{e}")
       end
-    rescue Errno::EADDRNOTAVAIL => e
-      warn "Could not assign address to graphite server #{server}: #{e}"
-    rescue StandardError => e
-      @logger.log('s', "[!] Failure logging #{path} to graphite server [#{server}:#{port}]: #{e}")
     end
   end
 end
diff --git a/lib/vmpooler/metrics/promstats.rb b/lib/vmpooler/metrics/promstats.rb
index 9a9e7a6..e385d17 100644
--- a/lib/vmpooler/metrics/promstats.rb
+++ b/lib/vmpooler/metrics/promstats.rb
@@ -3,304 +3,319 @@
 require 'prometheus/client'
 
 module Vmpooler
-  class Promstats < Metrics
-    attr_reader :prefix, :endpoint, :metrics_prefix
+  class Metrics
+    class Promstats < Metrics
+      attr_reader :prefix, :endpoint, :metrics_prefix
 
-    # Constants for Metric Types
-    M_COUNTER   = 1
-    M_GAUGE     = 2
-    M_SUMMARY   = 3
-    M_HISTOGRAM = 4
+      # Constants for Metric Types
+      M_COUNTER   = 1
+      M_GAUGE     = 2
+      M_SUMMARY   = 3
+      M_HISTOGRAM = 4
 
-    # Customised Bucket set to use for the Pooler clone times set to more appropriate intervals.
-    POOLER_TIME_BUCKETS = [1.0, 2.5, 5.0, 10.0, 20.0, 50.0, 100.0, 200.0, 500.0, 1000.0, 2000.0].freeze
-    # Same for Redis connection times - this is the same as the current Prometheus Default.
-    # https://github.com/prometheus/client_ruby/blob/master/lib/prometheus/client/histogram.rb#L14
-    REDIS_CONNECT_BUCKETS = [0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10].freeze
+      # Customised Bucket set to use for the Pooler clone times set to more appropriate intervals.
+      POOLER_TIME_BUCKETS = [1.0, 2.5, 5.0, 10.0, 20.0, 50.0, 100.0, 200.0, 500.0, 1000.0, 2000.0].freeze
+      # Same for redis connection times - this is the same as the current Prometheus Default.
+      # https://github.com/prometheus/client_ruby/blob/master/lib/prometheus/client/histogram.rb#L14
+      REDIS_CONNECT_BUCKETS = [0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10].freeze
 
-    @p_metrics = {}
+      @p_metrics = {}
 
-    def initialize(logger, params = {})
-      @prefix = params['prefix'] || 'vmpooler'
-      @metrics_prefix = params['metrics_prefix'] || 'vmpooler'
-      @endpoint = params['endpoint'] || '/prometheus'
-      @logger = logger
+      def initialize(logger, params = {})
+        @prefix = params['prefix'] || 'vmpooler'
+        @metrics_prefix = params['metrics_prefix'] || 'vmpooler'
+        @endpoint = params['endpoint'] || '/prometheus'
+        @logger = logger
 
-      # Setup up prometheus registry and data structures
-      @prometheus = Prometheus::Client.registry
-    end
+        # Setup up prometheus registry and data structures
+        @prometheus = Prometheus::Client.registry
+      end
 
-    # Metrics structure used to register the metrics and also translate/interpret the incoming metrics.
-    def vmpooler_metrics_table
-      {
-        errors: {
-          mtype: M_COUNTER,
-          docstring: 'Count of Errors for pool',
-          prom_metric_prefix: "#{@metrics_prefix}_errors",
-          metric_suffixes: {
-            markedasfailed: 'Timeout waiting for instance to initialise',
-            duplicatehostname: 'Unable to create instance due to duplicate hostname'
+      # Metrics structure used to register the metrics and also translate/interpret the incoming metrics.
+      def vmpooler_metrics_table
+        {
+          errors: {
+            mtype: M_COUNTER,
+            docstring: 'Count of errors for pool',
+            prom_metric_prefix: "#{@metrics_prefix}_errors",
+            metric_suffixes: {
+              markedasfailed: 'timeout waiting for instance to initialise',
+              duplicatehostname: 'unable to create instance due to duplicate hostname',
+              staledns: 'unable to create instance due to duplicate DNS record'
+            },
+            param_labels: %i[template_name]
           },
-          param_labels: %i[template_name]
-        },
-        user: {
-          mtype: M_COUNTER,
-          docstring: 'Number of Pool Instances this user created created',
-          prom_metric_prefix: "#{@metrics_prefix}_user",
-          param_labels: %i[user poolname]
-        },
-        usage_jenkins_instance: {
-          mtype: M_COUNTER,
-          docstring: 'Pools by Jenkins Instance usage',
-          prom_metric_prefix: "#{@metrics_prefix}_usage_jenkins_instance",
-          param_labels: %i[jenkins_instance value_stream poolname]
-        },
-        usage_branch_project: {
-          mtype: M_COUNTER,
-          docstring: 'Pools by branch/project usage',
-          prom_metric_prefix: "#{@metrics_prefix}_usage_branch_project",
-          param_labels: %i[branch project poolname]
-        },
-        usage_job_component: {
-          mtype: M_COUNTER,
-          docstring: 'Pools by job/component usage',
-          prom_metric_prefix: "#{@metrics_prefix}_usage_job_component",
-          param_labels: %i[job_name component_to_test poolname]
-        },
-        checkout: {
-          mtype: M_COUNTER,
-          docstring: 'Pool Checkout counts',
-          prom_metric_prefix: "#{@metrics_prefix}_checkout",
-          metric_suffixes: {
-            nonresponsive: 'Checkout Failed - Non Responsive Machine',
-            empty: 'Checkout Failed - no machine',
-            success: 'Successful Checkout',
-            invalid: 'Checkout Failed - Invalid Template'
+          user: {
+            mtype: M_COUNTER,
+            docstring: 'Number of pool instances this user created created',
+            prom_metric_prefix: "#{@metrics_prefix}_user",
+            param_labels: %i[user poolname]
           },
-          param_labels: %i[poolname]
-        },
-        config: {
-          mtype: M_COUNTER,
-          docstring: 'vmpooler Pool Configuration Request',
-          prom_metric_prefix: "#{@metrics_prefix}_config",
-          metric_suffixes: { invalid: 'Invalid' },
-          param_labels: %i[poolname]
-        },
-        poolreset: {
-          mtype: M_COUNTER,
-          docstring: 'Pool Reset Counter',
-          prom_metric_prefix: "#{@metrics_prefix}_poolreset",
-          metric_suffixes: { invalid: 'Invalid Pool' },
-          param_labels: %i[poolname]
-        },
-        connect: {
-          mtype: M_COUNTER,
-          docstring: 'vmpooler Connect (to vSphere)',
-          prom_metric_prefix: "#{@metrics_prefix}_connect",
-          metric_suffixes: {
-            open: 'Connect Succeeded',
-            fail: 'Connect Failed'
+          usage_litmus: {
+            mtype: M_COUNTER,
+            docstring: 'Pools by Litmus job usage',
+            prom_metric_prefix: "#{@metrics_prefix}_usage_litmus",
+            param_labels: %i[user poolname]
           },
-          param_labels: []
-        },
-        migrate_from: {
-          mtype: M_COUNTER,
-          docstring: 'vmpooler Machine Migrated from',
-          prom_metric_prefix: "#{@metrics_prefix}_migrate_from",
-          param_labels: %i[host_name]
-        },
-        migrate_to: {
-          mtype: M_COUNTER,
-          docstring: 'vmpooler Machine Migrated to',
-          prom_metric_prefix: "#{@metrics_prefix}_migrate_to",
-          param_labels: %i[host_name]
-        },
-        ready: {
-          mtype: M_GAUGE,
-          docstring: 'vmpooler Number of Machines in Ready State',
-          prom_metric_prefix: "#{@metrics_prefix}_ready",
-          param_labels: %i[poolname]
-        },
-        running: {
-          mtype: M_GAUGE,
-          docstring: 'vmpooler Number of Machines Running',
-          prom_metric_prefix: "#{@metrics_prefix}_running",
-          param_labels: %i[poolname]
-        },
-        connection_available: {
-          mtype: M_GAUGE,
-          docstring: 'vmpooler Redis Connections Available',
-          prom_metric_prefix: "#{@metrics_prefix}_connection_available",
-          param_labels: %i[type provider]
-        },
-        time_to_ready_state: {
-          mtype: M_HISTOGRAM,
-          buckets: POOLER_TIME_BUCKETS,
-          docstring: 'Time taken for machine to read ready state for pool',
-          prom_metric_prefix: "#{@metrics_prefix}_time_to_ready_state",
-          param_labels: %i[poolname]
-        },
-        migrate: {
-          mtype: M_HISTOGRAM,
-          buckets: POOLER_TIME_BUCKETS,
-          docstring: 'vmpooler Time taken to migrate machine for pool',
-          prom_metric_prefix: "#{@metrics_prefix}_migrate",
-          param_labels: %i[poolname]
-        },
-        clone: {
-          mtype: M_HISTOGRAM,
-          buckets: POOLER_TIME_BUCKETS,
-          docstring: 'vmpooler Time taken to Clone Machine',
-          prom_metric_prefix: "#{@metrics_prefix}_clone",
-          param_labels: %i[poolname]
-        },
-        destroy: {
-          mtype: M_HISTOGRAM,
-          buckets: POOLER_TIME_BUCKETS,
-          docstring: 'vmpooler Time taken to Destroy Machine',
-          prom_metric_prefix: "#{@metrics_prefix}_destroy",
-          param_labels: %i[poolname]
-        },
-        connection_waited: {
-          mtype: M_HISTOGRAM,
-          buckets: REDIS_CONNECT_BUCKETS,
-          docstring: 'vmpooler Redis Connection Wait Time',
-          prom_metric_prefix: "#{@metrics_prefix}_connection_waited",
-          param_labels: %i[type provider]
+          usage_jenkins_instance: {
+            mtype: M_COUNTER,
+            docstring: 'Pools by Jenkins instance usage',
+            prom_metric_prefix: "#{@metrics_prefix}_usage_jenkins_instance",
+            param_labels: %i[jenkins_instance value_stream poolname]
+          },
+          usage_branch_project: {
+            mtype: M_COUNTER,
+            docstring: 'Pools by branch/project usage',
+            prom_metric_prefix: "#{@metrics_prefix}_usage_branch_project",
+            param_labels: %i[branch project poolname]
+          },
+          usage_job_component: {
+            mtype: M_COUNTER,
+            docstring: 'Pools by job/component usage',
+            prom_metric_prefix: "#{@metrics_prefix}_usage_job_component",
+            param_labels: %i[job_name component_to_test poolname]
+          },
+          checkout: {
+            mtype: M_COUNTER,
+            docstring: 'Pool checkout counts',
+            prom_metric_prefix: "#{@metrics_prefix}_checkout",
+            metric_suffixes: {
+              nonresponsive: 'checkout failed - non responsive machine',
+              empty: 'checkout failed - no machine',
+              success: 'successful checkout',
+              invalid: 'checkout failed - invalid template'
+            },
+            param_labels: %i[poolname]
+          },
+          config: {
+            mtype: M_COUNTER,
+            docstring: 'vmpooler pool configuration request',
+            prom_metric_prefix: "#{@metrics_prefix}_config",
+            metric_suffixes: { invalid: 'Invalid' },
+            param_labels: %i[poolname]
+          },
+          poolreset: {
+            mtype: M_COUNTER,
+            docstring: 'Pool reset counter',
+            prom_metric_prefix: "#{@metrics_prefix}_poolreset",
+            metric_suffixes: { invalid: 'Invalid Pool' },
+            param_labels: %i[poolname]
+          },
+          connect: {
+            mtype: M_COUNTER,
+            docstring: 'vmpooler connect (to vSphere)',
+            prom_metric_prefix: "#{@metrics_prefix}_connect",
+            metric_suffixes: {
+              open: 'Connect Succeeded',
+              fail: 'Connect Failed'
+            },
+            param_labels: []
+          },
+          migrate_from: {
+            mtype: M_COUNTER,
+            docstring: 'vmpooler machine migrated from',
+            prom_metric_prefix: "#{@metrics_prefix}_migrate_from",
+            param_labels: %i[host_name]
+          },
+          migrate_to: {
+            mtype: M_COUNTER,
+            docstring: 'vmpooler machine migrated to',
+            prom_metric_prefix: "#{@metrics_prefix}_migrate_to",
+            param_labels: %i[host_name]
+          },
+          api_vm: {
+            mtype: M_COUNTER,
+            docstring: 'Total number of HTTP request/sub-operations handled by the Rack application under the /vm endpoint',
+            prom_metric_prefix: "#{@metrics_prefix}_http_requests_vm_total",
+            param_labels: %i[method subpath operation]
+          },
+          ready: {
+            mtype: M_GAUGE,
+            docstring: 'vmpooler number of machines in ready State',
+            prom_metric_prefix: "#{@metrics_prefix}_ready",
+            param_labels: %i[poolname]
+          },
+          running: {
+            mtype: M_GAUGE,
+            docstring: 'vmpooler number of machines running',
+            prom_metric_prefix: "#{@metrics_prefix}_running",
+            param_labels: %i[poolname]
+          },
+          connection_available: {
+            mtype: M_GAUGE,
+            docstring: 'vmpooler redis connections available',
+            prom_metric_prefix: "#{@metrics_prefix}_connection_available",
+            param_labels: %i[type provider]
+          },
+          time_to_ready_state: {
+            mtype: M_HISTOGRAM,
+            buckets: POOLER_TIME_BUCKETS,
+            docstring: 'Time taken for machine to read ready state for pool',
+            prom_metric_prefix: "#{@metrics_prefix}_time_to_ready_state",
+            param_labels: %i[poolname]
+          },
+          migrate: {
+            mtype: M_HISTOGRAM,
+            buckets: POOLER_TIME_BUCKETS,
+            docstring: 'vmpooler time taken to migrate machine for pool',
+            prom_metric_prefix: "#{@metrics_prefix}_migrate",
+            param_labels: %i[poolname]
+          },
+          clone: {
+            mtype: M_HISTOGRAM,
+            buckets: POOLER_TIME_BUCKETS,
+            docstring: 'vmpooler time taken to clone machine',
+            prom_metric_prefix: "#{@metrics_prefix}_clone",
+            param_labels: %i[poolname]
+          },
+          destroy: {
+            mtype: M_HISTOGRAM,
+            buckets: POOLER_TIME_BUCKETS,
+            docstring: 'vmpooler time taken to destroy machine',
+            prom_metric_prefix: "#{@metrics_prefix}_destroy",
+            param_labels: %i[poolname]
+          },
+          connection_waited: {
+            mtype: M_HISTOGRAM,
+            buckets: REDIS_CONNECT_BUCKETS,
+            docstring: 'vmpooler redis connection wait time',
+            prom_metric_prefix: "#{@metrics_prefix}_connection_waited",
+            param_labels: %i[type provider]
+          }
         }
-      }
-    end
-
-    # Helper to add individual prom metric.
-    # Allow Histograms to specify the bucket size.
-    def add_prometheus_metric(metric_spec, name, docstring)
-      case metric_spec[:mtype]
-      when M_COUNTER
-        metric_class = Prometheus::Client::Counter
-      when M_GAUGE
-        metric_class = Prometheus::Client::Gauge
-      when M_SUMMARY
-        metric_class = Prometheus::Client::Summary
-      when M_HISTOGRAM
-        metric_class = Prometheus::Client::Histogram
-      else
-        raise("Unable to register metric #{name} with metric type #{metric_spec[:mtype]}")
       end
 
-      if (metric_spec[:mtype] == M_HISTOGRAM) && (metric_spec.key? :buckets)
-        prom_metric = metric_class.new(
-          name.to_sym,
-          docstring: docstring,
-          labels: metric_spec[:param_labels] + [:vmpooler_instance],
-          buckets: metric_spec[:buckets],
-          preset_labels: { vmpooler_instance: @prefix }
-        )
-      else
-        prom_metric = metric_class.new(
-          name.to_sym,
-          docstring: docstring,
-          labels: metric_spec[:param_labels] + [:vmpooler_instance],
-          preset_labels: { vmpooler_instance: @prefix }
-        )
-      end
-      @prometheus.register(prom_metric)
-    end
-
-    # Top level method to register all the prometheus metrics.
-
-    def setup_prometheus_metrics
-      @p_metrics = vmpooler_metrics_table
-      @p_metrics.each do |_name, metric_spec|
-        if metric_spec.key? :metric_suffixes
-          # Iterate thru the suffixes if provided to register multiple counters here.
-          metric_spec[:metric_suffixes].each do |metric_suffix|
-            add_prometheus_metric(
-              metric_spec,
-              "#{metric_spec[:prom_metric_prefix]}_#{metric_suffix[0]}",
-              "#{metric_spec[:docstring]} #{metric_suffix[1]}"
-            )
-          end
+      # Helper to add individual prom metric.
+      # Allow Histograms to specify the bucket size.
+      def add_prometheus_metric(metric_spec, name, docstring)
+        case metric_spec[:mtype]
+        when M_COUNTER
+          metric_class = Prometheus::Client::Counter
+        when M_GAUGE
+          metric_class = Prometheus::Client::Gauge
+        when M_SUMMARY
+          metric_class = Prometheus::Client::Summary
+        when M_HISTOGRAM
+          metric_class = Prometheus::Client::Histogram
         else
-          # No Additional counter suffixes so register this as metric.
-          add_prometheus_metric(
-            metric_spec,
-            metric_spec[:prom_metric_prefix],
-            metric_spec[:docstring]
+          raise("Unable to register metric #{name} with metric type #{metric_spec[:mtype]}")
+        end
+
+        if (metric_spec[:mtype] == M_HISTOGRAM) && (metric_spec.key? :buckets)
+          prom_metric = metric_class.new(
+            name.to_sym,
+            docstring: docstring,
+            labels: metric_spec[:param_labels] + [:vmpooler_instance],
+            buckets: metric_spec[:buckets],
+            preset_labels: { vmpooler_instance: @prefix }
+          )
+        else
+          prom_metric = metric_class.new(
+            name.to_sym,
+            docstring: docstring,
+            labels: metric_spec[:param_labels] + [:vmpooler_instance],
+            preset_labels: { vmpooler_instance: @prefix }
           )
         end
-      end
-    end
-
-    # locate a metric and check/interpet the sub-fields.
-    def find_metric(label)
-      sublabels = label.split('.')
-      metric_key = sublabels.shift.to_sym
-      raise("Invalid Metric #{metric_key} for #{label}") unless @p_metrics.key? metric_key
-
-      metric = @p_metrics[metric_key].clone
-
-      if metric.key? :metric_suffixes
-        metric_subkey = sublabels.shift.to_sym
-        raise("Invalid Metric #{metric_key}_#{metric_subkey} for #{label}") unless metric[:metric_suffixes].key? metric_subkey.to_sym
-
-        metric[:metric_name] = "#{metric[:prom_metric_prefix]}_#{metric_subkey}"
-      else
-        metric[:metric_name] = metric[:prom_metric_prefix]
+        @prometheus.register(prom_metric)
       end
 
-      # Check if we are looking for a parameter value at last element.
-      if metric.key? :param_labels
-        metric[:labels] = {}
-        # Special case processing here - if there is only one parameter label then make sure
-        # we append all of the remaining contents of the metric with "." separators to ensure
-        # we get full nodenames (e.g. for Migration to node operations)
-        if metric[:param_labels].length == 1
-          metric[:labels][metric[:param_labels].first] = sublabels.join('.')
-        else
-          metric[:param_labels].reverse_each do |param_label|
-            metric[:labels][param_label] = sublabels.pop(1).first
+      # Top level method to register all the prometheus metrics.
+
+      def setup_prometheus_metrics
+        @p_metrics = vmpooler_metrics_table
+        @p_metrics.each do |_name, metric_spec|
+          if metric_spec.key? :metric_suffixes
+            # Iterate thru the suffixes if provided to register multiple counters here.
+            metric_spec[:metric_suffixes].each do |metric_suffix|
+              add_prometheus_metric(
+                metric_spec,
+                "#{metric_spec[:prom_metric_prefix]}_#{metric_suffix[0]}",
+                "#{metric_spec[:docstring]} #{metric_suffix[1]}"
+              )
+            end
+          else
+            # No Additional counter suffixes so register this as metric.
+            add_prometheus_metric(
+              metric_spec,
+              metric_spec[:prom_metric_prefix],
+              metric_spec[:docstring]
+            )
           end
         end
       end
-      metric
-    end
 
-    # Helper to get lab metrics.
-    def get(label)
-      metric = find_metric(label)
-      [metric, @prometheus.get(metric[:metric_name])]
-    end
+      # locate a metric and check/interpet the sub-fields.
+      def find_metric(label)
+        sublabels = label.split('.')
+        metric_key = sublabels.shift.to_sym
+        raise("Invalid Metric #{metric_key} for #{label}") unless @p_metrics.key? metric_key
 
-    # Note - Catch and log metrics failures so they can be noted, but don't interrupt vmpooler operation.
-    def increment(label)
-      begin
-        counter_metric, c = get(label)
-        c.increment(labels: counter_metric[:labels])
-      rescue StandardError => e
-        @logger.log('s', "[!] prometheus error logging metric #{label} increment : #{e}")
-      end
-    end
+        metric = @p_metrics[metric_key].clone
 
-    def gauge(label, value)
-      begin
-        unless value.nil?
-          gauge_metric, g = get(label)
-          g.set(value.to_i, labels: gauge_metric[:labels])
+        if metric.key? :metric_suffixes
+          metric_subkey = sublabels.shift.to_sym
+          raise("Invalid Metric #{metric_key}_#{metric_subkey} for #{label}") unless metric[:metric_suffixes].key? metric_subkey.to_sym
+
+          metric[:metric_name] = "#{metric[:prom_metric_prefix]}_#{metric_subkey}"
+        else
+          metric[:metric_name] = metric[:prom_metric_prefix]
         end
-      rescue StandardError => e
-        @logger.log('s', "[!] prometheus error logging gauge #{label}, value #{value}: #{e}")
-      end
-    end
 
-    def timing(label, duration)
-      begin
-        # https://prometheus.io/docs/practices/histograms/
-        unless duration.nil?
-          histogram_metric, hm = get(label)
-          hm.observe(duration.to_f, labels: histogram_metric[:labels])
+        # Check if we are looking for a parameter value at last element.
+        if metric.key? :param_labels
+          metric[:labels] = {}
+          # Special case processing here - if there is only one parameter label then make sure
+          # we append all of the remaining contents of the metric with "." separators to ensure
+          # we get full nodenames (e.g. for Migration to node operations)
+          if metric[:param_labels].length == 1
+            metric[:labels][metric[:param_labels].first] = sublabels.join('.')
+          else
+            metric[:param_labels].reverse_each do |param_label|
+              metric[:labels][param_label] = sublabels.pop(1).first
+            end
+          end
+        end
+        metric
+      end
+
+      # Helper to get lab metrics.
+      def get(label)
+        metric = find_metric(label)
+        [metric, @prometheus.get(metric[:metric_name])]
+      end
+
+      # Note - Catch and log metrics failures so they can be noted, but don't interrupt vmpooler operation.
+      def increment(label)
+        begin
+          counter_metric, c = get(label)
+          c.increment(labels: counter_metric[:labels])
+        rescue StandardError => e
+          @logger.log('s', "[!] prometheus error logging metric #{label} increment : #{e}")
+        end
+      end
+
+      def gauge(label, value)
+        begin
+          unless value.nil?
+            gauge_metric, g = get(label)
+            g.set(value.to_i, labels: gauge_metric[:labels])
+          end
+        rescue StandardError => e
+          @logger.log('s', "[!] prometheus error logging gauge #{label}, value #{value}: #{e}")
+        end
+      end
+
+      def timing(label, duration)
+        begin
+          # https://prometheus.io/docs/practices/histograms/
+          unless duration.nil?
+            histogram_metric, hm = get(label)
+            hm.observe(duration.to_f, labels: histogram_metric[:labels])
+          end
+        rescue StandardError => e
+          @logger.log('s', "[!] prometheus error logging timing event label #{label}, duration #{duration}: #{e}")
         end
-      rescue StandardError => e
-        @logger.log('s', "[!] prometheus error logging timing event label #{label}, duration #{duration}: #{e}")
       end
     end
   end
diff --git a/lib/vmpooler/metrics/statsd.rb b/lib/vmpooler/metrics/statsd.rb
index def7b58..85b705d 100644
--- a/lib/vmpooler/metrics/statsd.rb
+++ b/lib/vmpooler/metrics/statsd.rb
@@ -4,35 +4,37 @@ require 'rubygems' unless defined?(Gem)
 require 'statsd'
 
 module Vmpooler
-  class Statsd < Metrics
-    attr_reader :server, :port, :prefix
+  class Metrics
+    class Statsd < Metrics
+      attr_reader :server, :port, :prefix
 
-    def initialize(logger, params = {})
-      raise ArgumentError, "Statsd server is required. Config: #{params.inspect}" if params['server'].nil? || params['server'].empty?
+      def initialize(logger, params = {})
+        raise ArgumentError, "Statsd server is required. Config: #{params.inspect}" if params['server'].nil? || params['server'].empty?
 
-      host    = params['server']
-      @port   = params['port'] || 8125
-      @prefix = params['prefix'] || 'vmpooler'
-      @server = ::Statsd.new(host, @port)
-      @logger = logger
-    end
+        host    = params['server']
+        @port   = params['port'] || 8125
+        @prefix = params['prefix'] || 'vmpooler'
+        @server = ::Statsd.new(host, @port)
+        @logger = logger
+      end
 
-    def increment(label)
-      server.increment(prefix + '.' + label)
-    rescue StandardError => e
-      @logger.log('s', "[!] Failure incrementing #{prefix}.#{label} on statsd server [#{server}:#{port}]: #{e}")
-    end
+      def increment(label)
+        server.increment(prefix + '.' + label)
+      rescue StandardError => e
+        @logger.log('s', "[!] Failure incrementing #{prefix}.#{label} on statsd server [#{server}:#{port}]: #{e}")
+      end
 
-    def gauge(label, value)
-      server.gauge(prefix + '.' + label, value)
-    rescue StandardError => e
-      @logger.log('s', "[!] Failure updating gauge #{prefix}.#{label} on statsd server [#{server}:#{port}]: #{e}")
-    end
+      def gauge(label, value)
+        server.gauge(prefix + '.' + label, value)
+      rescue StandardError => e
+        @logger.log('s', "[!] Failure updating gauge #{prefix}.#{label} on statsd server [#{server}:#{port}]: #{e}")
+      end
 
-    def timing(label, duration)
-      server.timing(prefix + '.' + label, duration)
-    rescue StandardError => e
-      @logger.log('s', "[!] Failure updating timing #{prefix}.#{label} on statsd server [#{server}:#{port}]: #{e}")
+      def timing(label, duration)
+        server.timing(prefix + '.' + label, duration)
+      rescue StandardError => e
+        @logger.log('s', "[!] Failure updating timing #{prefix}.#{label} on statsd server [#{server}:#{port}]: #{e}")
+      end
     end
   end
 end
diff --git a/spec/integration/api/v1/config_spec.rb b/spec/integration/api/v1/config_spec.rb
index 7462307..655a2cc 100644
--- a/spec/integration/api/v1/config_spec.rb
+++ b/spec/integration/api/v1/config_spec.rb
@@ -34,7 +34,7 @@ describe Vmpooler::API::V1 do
 
   describe '/config/pooltemplate' do
     let(:prefix) { '/api/v1' }
-    let(:metrics) { Vmpooler::DummyStatsd.new }
+    let(:metrics) { Vmpooler::Metrics::DummyStatsd.new }
 
     let(:current_time) { Time.now }
 
diff --git a/spec/integration/api/v1/ondemandvm_spec.rb b/spec/integration/api/v1/ondemandvm_spec.rb
index f9b31b2..6ab0076 100644
--- a/spec/integration/api/v1/ondemandvm_spec.rb
+++ b/spec/integration/api/v1/ondemandvm_spec.rb
@@ -16,7 +16,7 @@ describe Vmpooler::API::V1 do
 
   describe '/ondemandvm' do
     let(:prefix) { '/api/v1' }
-    let(:metrics) { Vmpooler::DummyStatsd.new }
+    let(:metrics) { Vmpooler::Metrics::DummyStatsd.new }
     let(:config) {
       {
         config: {
diff --git a/spec/integration/api/v1/poolreset.rb b/spec/integration/api/v1/poolreset.rb
index 043989e..35e2ba4 100644
--- a/spec/integration/api/v1/poolreset.rb
+++ b/spec/integration/api/v1/poolreset.rb
@@ -31,7 +31,7 @@ describe Vmpooler::API::V1 do
 
   describe '/poolreset' do
     let(:prefix) { '/api/v1' }
-    let(:metrics) { Vmpooler::DummyStatsd.new }
+    let(:metrics) { Vmpooler::Metrics::DummyStatsd.new }
 
     let(:current_time) { Time.now }
 
diff --git a/spec/integration/api/v1/vm_hostname_spec.rb b/spec/integration/api/v1/vm_hostname_spec.rb
index 18fcec3..25201a8 100644
--- a/spec/integration/api/v1/vm_hostname_spec.rb
+++ b/spec/integration/api/v1/vm_hostname_spec.rb
@@ -21,7 +21,7 @@ describe Vmpooler::API::V1 do
 
   describe '/vm/:hostname' do
     let(:prefix) { '/api/v1' }
-    let(:metrics) { Vmpooler::DummyStatsd.new }
+    let(:metrics) { Vmpooler::Metrics::DummyStatsd.new }
 
     let(:config) {
       {
diff --git a/spec/integration/api/v1/vm_spec.rb b/spec/integration/api/v1/vm_spec.rb
index 7f5c29a..15b6074 100644
--- a/spec/integration/api/v1/vm_spec.rb
+++ b/spec/integration/api/v1/vm_spec.rb
@@ -17,7 +17,7 @@ describe Vmpooler::API::V1 do
 
   describe '/vm' do
     let(:prefix) { '/api/v1' }
-    let(:metrics) { Vmpooler::DummyStatsd.new }
+    let(:metrics) { Vmpooler::Metrics::DummyStatsd.new }
     let(:config) {
       {
         config: {
diff --git a/spec/integration/api/v1/vm_template_spec.rb b/spec/integration/api/v1/vm_template_spec.rb
index da83116..839b427 100644
--- a/spec/integration/api/v1/vm_template_spec.rb
+++ b/spec/integration/api/v1/vm_template_spec.rb
@@ -17,7 +17,7 @@ describe Vmpooler::API::V1 do
 
   describe '/vm/:template' do
     let(:prefix) { '/api/v1' }
-    let(:metrics) { Vmpooler::DummyStatsd.new }
+    let(:metrics) { Vmpooler::Metrics::DummyStatsd.new }
     let(:config) {
       {
         config: {
diff --git a/spec/unit/pool_manager_spec.rb b/spec/unit/pool_manager_spec.rb
index ed7d0ae..446d1ba 100644
--- a/spec/unit/pool_manager_spec.rb
+++ b/spec/unit/pool_manager_spec.rb
@@ -10,7 +10,7 @@ RSpec::Matchers.define :a_pool_with_name_of do |value|
 end
 describe 'Pool Manager' do
   let(:logger) { MockLogger.new }
-  let(:metrics) { Vmpooler::DummyStatsd.new }
+  let(:metrics) { Vmpooler::Metrics::DummyStatsd.new }
   let(:pool) { 'pool1' }
   let(:vm) { 'vm1' }
   let(:timeout) { 5 }
diff --git a/spec/unit/promstats_spec.rb b/spec/unit/promstats_spec.rb
index d721cce..62c8f4a 100644
--- a/spec/unit/promstats_spec.rb
+++ b/spec/unit/promstats_spec.rb
@@ -5,12 +5,12 @@ require 'spec_helper'
 describe 'prometheus' do
   logger = MockLogger.new
   params = { 'prefix': 'test', 'metrics_prefix': 'mtest', 'endpoint': 'eptest' }
-  subject = Vmpooler::Promstats.new(logger, params)
+  subject = Vmpooler::Metrics::Promstats.new(logger, params)
   let(:logger) { MockLogger.new }
 
   describe '#initialise' do
     it 'returns a Metrics object' do
-      expect(Vmpooler::Promstats.new(logger)).to be_a(Vmpooler::Metrics)
+      expect(Vmpooler::Metrics::Promstats.new(logger)).to be_a(Vmpooler::Metrics)
     end
   end
 
@@ -142,6 +142,13 @@ describe 'prometheus' do
           po.get(labels: metric[:labels])
         }.by(1)
       end
+      it 'Increments errors.staledns.#{pool_name}' do
+        pool_name = 'test-pool'
+        expect { subject.increment("errors.staledns.#{pool_name}") }.to change {
+          metric, po = subject.get("errors.staledns.#{pool_name}")
+          po.get(labels: metric[:labels])
+        }.by(1)
+      end
       it 'Increments user.#{user}.#{poolname}' do
         user = 'myuser'
         poolname = 'test-pool'
@@ -150,6 +157,14 @@ describe 'prometheus' do
           po.get(labels: metric[:labels])
         }.by(1)
       end
+      it 'Increments usage_litmus.#{user}.#{poolname}' do
+        user = 'myuser'
+        poolname = 'test-pool'
+        expect { subject.increment("usage_litmus.#{user}.#{poolname}") }.to change {
+          metric, po = subject.get("usage_litmus.#{user}.#{poolname}")
+          po.get(labels: metric[:labels])
+        }.by(1)
+      end
       it 'Increments label usage_jenkins_instance.#{jenkins_instance}.#{value_stream}.#{poolname}' do
         jenkins_instance = 'jenkins_test_instance'
         value_stream = 'notional_value'
@@ -177,7 +192,6 @@ describe 'prometheus' do
           po.get(labels: metric[:labels])
         }.by(1)
       end
-
       it 'Increments connect.open' do
         expect { subject.increment('connect.open') }.to change {
           metric, po = subject.get('connect.open')
@@ -204,6 +218,16 @@ describe 'prometheus' do
           po.get(labels: metric[:labels])
         }.by(1)
       end
+      it 'Increments label api_vm.#{method}.#{subpath}.#{operation}' do
+        method = 'get'
+        subpath = 'template'
+        operation = 'something'
+        expect { subject.increment("api_vm.#{method}.#{subpath}.#{operation}") }.to change {
+          metric, po = subject.get("api_vm.#{method}.#{subpath}.#{operation}")
+          po.get(labels: metric[:labels])
+        }.by(1)
+      end
+
     end
 
     describe '#gauge' do
diff --git a/spec/unit/providers/base_spec.rb b/spec/unit/providers/base_spec.rb
index 27b3d94..1cc2090 100644
--- a/spec/unit/providers/base_spec.rb
+++ b/spec/unit/providers/base_spec.rb
@@ -6,7 +6,7 @@ require 'vmpooler/providers/base'
 
 describe 'Vmpooler::PoolManager::Provider::Base' do
   let(:logger) { MockLogger.new }
-  let(:metrics) { Vmpooler::DummyStatsd.new }
+  let(:metrics) { Vmpooler::Metrics::DummyStatsd.new }
   let(:config) { {} }
   let(:provider_name) { 'base' }
   let(:provider_options) { { 'param' => 'value' } }
diff --git a/spec/unit/providers/dummy_spec.rb b/spec/unit/providers/dummy_spec.rb
index a22d2e6..f4e4849 100644
--- a/spec/unit/providers/dummy_spec.rb
+++ b/spec/unit/providers/dummy_spec.rb
@@ -3,7 +3,7 @@ require 'vmpooler/providers/dummy'
 
 describe 'Vmpooler::PoolManager::Provider::Dummy' do
   let(:logger) { MockLogger.new }
-  let(:metrics) { Vmpooler::DummyStatsd.new }
+  let(:metrics) { Vmpooler::Metrics::DummyStatsd.new }
   let(:pool_name) { 'pool1' }
   let(:other_pool_name) { 'pool2' }
   let(:vm_name) { 'vm1' }
diff --git a/spec/unit/providers/vsphere_spec.rb b/spec/unit/providers/vsphere_spec.rb
index 90146b9..a2970ac 100644
--- a/spec/unit/providers/vsphere_spec.rb
+++ b/spec/unit/providers/vsphere_spec.rb
@@ -41,7 +41,7 @@ end
 
 describe 'Vmpooler::PoolManager::Provider::VSphere' do
   let(:logger) { MockLogger.new }
-  let(:metrics) { Vmpooler::DummyStatsd.new }
+  let(:metrics) { Vmpooler::Metrics::DummyStatsd.new }
   let(:poolname) { 'pool1'}
   let(:provider_options) { { 'param' => 'value' } }
   let(:datacenter_name) { 'MockDC' }