fix(event-loop): get values from libuv

lib/providers/apmMetrics/index.js

@@ -1,6 +1,6 @@
 var os = require('os')
-var blocked = require('blocked')
-var gc = (require('gc-stats'))()
+var gc = require('gc-stats')()
+var eventLoopStats = require('event-loop-stats')
 
 var BYTES_TO_MEGABYTES = 1024 * 1024
 
@@ -15,8 +15,6 @@ function ApmMetrics (eventBus) {
     scavenge: 0,
     marksweep: 0
   }
-  this.eventLoopLag = {}
-  this.eventLoopLag[this.lagId] = []
 
   var _this = this
 
@@ -41,10 +39,6 @@ function ApmMetrics (eventBus) {
         break
     }
   })
-
-  blocked(function (ms) {
-    _this.eventLoopLag[_this.lagId].push(ms)
-  })
 }
 
 ApmMetrics.prototype.getMetrics = function () {
@@ -83,17 +77,8 @@ ApmMetrics.prototype._bytesToMegaBytes = function (bytes) {
 }
 
 ApmMetrics.prototype.getEventLoop = function () {
-  this.eventLoopLag[++this.lagId] = []
-  if (this.eventLoopLag[this.lagId - 2]) {
-    delete this.eventLoopLag[this.lagId - 2]
-  }
-
-  var eventLoopLag = this.eventLoopLag[this.lagId - 1].reduce(function (total, curr) {
-    return total + curr
-  }, 0)
-
   return {
-    lag: eventLoopLag,
+    stats: eventLoopStats.sense(),
     requests: process._getActiveRequests().length,
     handlers: process._getActiveHandles().length
   }
@@ -105,12 +90,6 @@ ApmMetrics.prototype.reset = function () {
     scavenge: 0,
     marksweep: 0
   }
-
-  this.eventloop = {
-    lag: 0,
-    requests: 0,
-    handlers: 0
-  }
 }
 
 function create (eventBus) {

lib/providers/apmMetrics/index.spec.js

@@ -1,5 +1,6 @@
 var expect = require('chai').expect
 var os = require('os')
+var eventLoopStats = require('event-loop-stats')
 
 var ApmMetrics = require('./')
 
@@ -21,6 +22,13 @@ describe('The ApmMetrics module', function () {
     var memoryTotal = 12000000
     var memoryRss = 15000000
 
+    var _eventLoopStats = {
+      max: 10,
+      min: 0,
+      sum: 100,
+      num: 32
+    }
+
     var event = {
       emit: function (name, data) {
         expect(name).to.eql('apm')
@@ -33,7 +41,7 @@ describe('The ApmMetrics module', function () {
           eventloop: {
             handlers: activeHandlers,
             requests: activeRequests,
-            lag: 30
+            stats: _eventLoopStats
           },
           cpu: {
             utilization: Math.floor(loadAvg)
@@ -53,8 +61,10 @@ describe('The ApmMetrics module', function () {
     var apmMetrics = ApmMetrics.create(event)
 
     apmMetrics.lagId = 1
-    apmMetrics.eventLoopLag[1] = [10, 20]
 
+    this.sandbox.stub(eventLoopStats, 'sense', function () {
+      return _eventLoopStats
+    })
     this.sandbox.stub(process, '_getActiveRequests', function () {
       return new Array(activeRequests)
     })

package.json

@@ -35,9 +35,9 @@
   },
   "dependencies": {
     "bl": "1.0.1",
-    "blocked": "1.1.0",
     "continuation-local-storage": "3.1.6",
     "debug": "2.2.0",
+    "event-loop-stats": "1.0.0",
     "gc-stats": "1.0.0",
     "lodash.defaults": "4.0.1",
     "microtime": "2.0.0",