diff --git a/logstash-core/lib/logstash/agent.rb b/logstash-core/lib/logstash/agent.rb
index 4db2fada7..21fa2196e 100644
--- a/logstash-core/lib/logstash/agent.rb
+++ b/logstash-core/lib/logstash/agent.rb
@@ -113,13 +113,13 @@ class LogStash::Agent
     ((Time.now.to_f - STARTED_AT.to_f) * 1000.0).to_i
   end
 
-  def stop_collecting_metric
+  def stop_collecting_metrics
     @collector.stop
     @periodic_pollers.stop
   end
 
   def shutdown
-    stop_collecting_metric
+    stop_collecting_metrics
     stop_webserver
     shutdown_pipelines
   end
@@ -164,7 +164,7 @@ class LogStash::Agent
   end
 
   def reset_metrics_collectors
-    stop_collecting_metric
+    stop_collecting_metrics
     configure_metrics_collectors
   end
 
@@ -266,8 +266,6 @@ class LogStash::Agent
   def upgrade_pipeline(pipeline_id, new_pipeline)
     stop_pipeline(pipeline_id)
     @pipelines[pipeline_id] = new_pipeline
-
-    new_pipeline = metric
     start_pipeline(pipeline_id)
   end
 
diff --git a/logstash-core/lib/logstash/api/rack_app.rb b/logstash-core/lib/logstash/api/rack_app.rb
index a7d326bb1..6c551b327 100644
--- a/logstash-core/lib/logstash/api/rack_app.rb
+++ b/logstash-core/lib/logstash/api/rack_app.rb
@@ -104,7 +104,7 @@ module LogStash
           "/_node" => LogStash::Api::Modules::Node,
           "/_stats" => LogStash::Api::Modules::Stats,
           "/_node/stats" => LogStash::Api::Modules::NodeStats,
-          "/_plugins" => LogStash::Api::Modules::Plugins,
+          "/_plugins" => LogStash::Api::Modules::Plugins
         }
       end
     end
diff --git a/logstash-core/lib/logstash/api/service.rb b/logstash-core/lib/logstash/api/service.rb
index 183451c8e..d286f8f0c 100644
--- a/logstash-core/lib/logstash/api/service.rb
+++ b/logstash-core/lib/logstash/api/service.rb
@@ -35,12 +35,6 @@ module LogStash
         end
         LogStash::Json.dump(data)
       end
-
-      private
-
-      def has_counters?
-        true
-      end
     end
   end
 end
diff --git a/logstash-core/lib/logstash/pipeline.rb b/logstash-core/lib/logstash/pipeline.rb
index 46c3e4318..8c6a6cf22 100644
--- a/logstash-core/lib/logstash/pipeline.rb
+++ b/logstash-core/lib/logstash/pipeline.rb
@@ -41,7 +41,7 @@ module LogStash; class Pipeline
     "LogStash::Inputs::Stdin"
   ]
 
-  def initialize(config_str, settings = LogStash::SETTINGS, provided_metric = nil)
+  def initialize(config_str, settings = LogStash::SETTINGS, namespaced_metric = nil)
     @config_str = config_str
     @logger = Cabin::Channel.get(LogStash)
     @settings = settings
@@ -56,7 +56,7 @@ module LogStash; class Pipeline
 
     # This needs to be configured before we evaluate the code to make
     # sure the metric instance is correctly send to the plugins to make the namespace scoping work
-    @metric = provided_metric.nil? ? LogStash::Instrument::NullMetric.new : provided_metric
+    @metric = namespaced_metric.nil? ? LogStash::Instrument::NullMetric.new : namespaced_metric
 
     grammar = LogStashConfigParser.new
     @config = grammar.parse(config_str)
diff --git a/logstash-core/spec/logstash/agent_spec.rb b/logstash-core/spec/logstash/agent_spec.rb
index 3bc59233b..64aa3ee3c 100644
--- a/logstash-core/spec/logstash/agent_spec.rb
+++ b/logstash-core/spec/logstash/agent_spec.rb
@@ -381,10 +381,13 @@ describe LogStash::Agent do
     end
 
     after :each do
-      subject.shutdown
-      Stud.stop!(@t)
-      @t.join
-      Thread.abort_on_exception = @abort_on_exception
+      begin
+        subject.shutdown
+        Stud.stop!(@t)
+        @t.join
+      ensure
+        Thread.abort_on_exception = @abort_on_exception
+      end
     end
 
     it "resets the metric collector" do