fix(errorCount): limit error count to 20 per payload

Author: gergelyke

lib/agent/index.js

@@ -11,6 +11,7 @@ var consts = require('../consts')
 
 var REQUEST_ID = 'request-id'
 var SPAN_ID = 'span-id'
+var MUST_COLLECT_LIMIT = 20
 
 function Agent (options) {
   debug('Agent is initializing...')
@@ -24,6 +25,7 @@ function Agent (options) {
   this.sampleSize = this.config.sampleSize
 
   this.totalRequestCount = 0
+  this.mustCollectCount = 0
 
   // init required variables
   this.partials = {}
@@ -131,7 +133,11 @@ Agent.prototype.serverSend = function (data) {
   span.isSampled = (1 / this.sampleRate) > Math.random()
   span.isForceSampled = span.isForceSampled || data.mustCollect === consts.MUST_COLLECT.ERROR
 
-  if (span.isForceSampled || span.isSampled) {
+  if (span.isForceSampled) {
+    this.mustCollectCount += 1
+  }
+
+  if ((span.isForceSampled || span.isSampled) && this.mustCollectCount <= MUST_COLLECT_LIMIT) {
     this.spans.push(span)
   }
 
@@ -395,6 +401,7 @@ Agent.prototype._send = function (options) {
     this.totalRequestCount = 0
 
     this.spans = []
+    this.mustCollectCount = 0
     this.collectorApi.sendSamples(dataBag, options && options.isSync)
   }
 }

lib/agent/index.spec.js

@@ -331,4 +331,28 @@ describe('The Trace agent', function () {
       spans: [1, 2, 3]
     })
   })
+
+  it('limits must-collect count to 20', function () {
+    var statusCode = 200
+    agent.mustCollectCount = 20
+    agent.serverReceive({
+      id: transactionId,
+      spanId: spanId,
+      parentId: parentId,
+      url: url,
+      host: host,
+      method: 'GET'
+    })
+
+    agent.serverSend({
+      id: transactionId,
+      spanId: spanId,
+      responseTime: responseTime,
+      statusCode: statusCode,
+      mustCollect: '1'
+    })
+
+    expect(agent.spans).to.eql([])
+    expect(agent.mustCollectCount).to.eql(21)
+  })
 })