Add uptime millis stats

Fixes #6236

logstash-core/lib/logstash/api/commands/stats.rb

@@ -8,6 +8,8 @@ module LogStash
     module Commands
       class Stats < Commands::Base
         def jvm
+          require "pry"
+          binding.pry
           {
             :threads => extract_metrics(
               [:jvm, :threads],
@@ -15,7 +17,8 @@ module LogStash
               :peak_count
             ),
             :mem => memory,
-            :gc => gc
+            :gc => gc,
+            :uptime_in_millis => service.get_shallow(:jvm, :uptime_in_millis)
           }
         end
 

logstash-core/lib/logstash/instrument/periodic_poller/jvm.rb

@@ -7,6 +7,7 @@ require "set"
 java_import 'java.lang.management.ManagementFactory'
 java_import 'java.lang.management.OperatingSystemMXBean'
 java_import 'java.lang.management.GarbageCollectorMXBean'
+java_import 'java.lang.management.RuntimeMXBean'
 java_import 'com.sun.management.UnixOperatingSystemMXBean'
 java_import 'javax.management.MBeanServer'
 java_import 'javax.management.ObjectName'
@@ -41,12 +42,11 @@ module LogStash module Instrument module PeriodicPoller
 
     def collect
       raw = JRMonitor.memory.generate
-      collect_heap_metrics(raw)
-      collect_non_heap_metrics(raw)
+      collect_jvm_metrics(raw)      
       collect_pools_metrics(raw)
       collect_threads_metrics
       collect_process_metrics
-      collect_gc_stats
+      collect_gc_stats      
     end
 
     private
@@ -98,9 +98,16 @@ module LogStash module Instrument module PeriodicPoller
 
       metric.gauge(path + [:mem], :total_virtual_in_bytes, process_metrics["mem"]["total_virtual_in_bytes"])
     end
+    
+    def collect_jvm_metrics(data)
+      runtime_mx_bean = ManagementFactory.getRuntimeMXBean()
+      metric.gauge(:jvm, :uptime_in_millis, runtime_mx_bean.getUptime())
+      collect_heap_metrics(data)
+      collect_non_heap_metrics(data)
+    end  
 
     def collect_heap_metrics(data)
-      heap = aggregate_information_for(data["heap"].values)
+      heap = aggregate_information_for(data["heap"].values)      
       heap[:used_percent] = (heap[:used_in_bytes] / heap[:max_in_bytes].to_f)*100.0
 
       heap.each_pair do |key, value|