feat(ignore): requests can be ignored based on status codes

Author: gergelyke

README.md

@@ -56,6 +56,10 @@ module.exports = {
   },
   ignorePaths: [
     '/healthcheck'
+  ],
+  ignoreStatusCodes: [
+    401,
+    404
   ]
 }
 ```

example/config/trace.config.js

@@ -10,5 +10,9 @@
    },
    ignorePaths: [
      '/healtcheck'
+   ],
+   ignoreStatusCodes: [
+     401,
+     403
    ]
  }

lib/agent/index.js

@@ -137,8 +137,6 @@ Agent.prototype.serverSend = function (data) {
     this.reservoirSampler.addReturnsSuccess(span)
   }
 
-  this.rpmMetrics.addResponseTime(data.responseTime)
-  this.rpmMetrics.addStatusCode(data.statusCode)
   delete this.partials[data.id]
 }
 
@@ -362,6 +360,10 @@ Agent.prototype.getSpanId = function () {
   return this.cls.get(SPAN_ID)
 }
 
+Agent.prototype.clearTransaction = function (requestId) {
+  delete this.partials[requestId]
+}
+
 Agent.prototype.bind = function (fn) {
   return this.cls.bind(fn)
 }

lib/agent/index.spec.js

@@ -147,8 +147,6 @@ describe('The Trace agent', function () {
       mustCollect: '1'
     })
 
-    expect(rpmMetrics.addResponseTime).to.have.been.calledWith(responseTime)
-    expect(rpmMetrics.addStatusCode).to.have.been.calledWith(statusCode)
     expect(agent.totalRequestCount).to.eql(1)
     expect(agent.partials).to.eql({})
     expect(agent.reservoirSampler.getItems()).to.eql([{
@@ -310,6 +308,15 @@ describe('The Trace agent', function () {
     })
   })
 
+  it('clears a transaction', function () {
+    agent.partials[transactionId] = {
+      data: 'something'
+    }
+
+    agent.clearTransaction(transactionId)
+    expect(agent.partials).to.eql({})
+  })
+
   it('passes sample and span data to the API client', function () {
     agent.reservoirSampler.addReturnsSuccess(1)
     agent.totalRequestCount = 6

lib/instrumentations/core/http/server.js

@@ -19,10 +19,25 @@ function isPathIgnored (ignorePaths, currentPath) {
   return false
 }
 
+function isStatusCodeIgnored (ignoreStatusCodes, statusCode) {
+  if (!ignoreStatusCodes || !ignoreStatusCodes.length) {
+    return false
+  }
+
+  for (var i = 0; i < ignoreStatusCodes.length; i++) {
+    if (statusCode === ignoreStatusCodes[i]) {
+      return true
+    }
+  }
+
+  return false
+}
+
 function wrapListener (listener, agent, mustCollectStore) {
   var config = agent.getConfig()
   var ignoreHeaders = config.ignoreHeaders
   var ignorePaths = config.ignorePaths
+  var ignoreStatusCodes = config.ignoreStatusCodes
 
   return function (request, response) {
     var requestUrl = request.url.split('?')[0]
@@ -60,7 +75,7 @@ function wrapListener (listener, agent, mustCollectStore) {
     var method = request.method
     serverReceiveTime = microtime.now()
 
-    var collectorDataBag = {
+    var serverReceiveData = {
       id: requestId,
       spanId: spanId,
       host: headers.host,
@@ -73,7 +88,7 @@ function wrapListener (listener, agent, mustCollectStore) {
     }
 
     // Collect request start
-    agent.serverReceive(collectorDataBag)
+    agent.serverReceive(serverReceiveData)
 
     var serverSendTime
     /*
@@ -82,7 +97,15 @@ function wrapListener (listener, agent, mustCollectStore) {
     function instrumentedFinish () {
       var responseTime = serverSendTime - serverReceiveTime
 
-      var collectorDataBag = {
+      agent.rpmMetrics.addResponseTime(responseTime)
+      agent.rpmMetrics.addStatusCode(response.statusCode)
+
+      if (isStatusCodeIgnored(ignoreStatusCodes, response.statusCode)) {
+        agent.clearTransaction(requestId)
+        return debug('statusCode %s is ignored', response.statusCode)
+      }
+
+      var serverSendData = {
         mustCollect: mustCollectStore[requestId],
         id: requestId,
         spanId: headers['x-span-id'],
@@ -96,7 +119,7 @@ function wrapListener (listener, agent, mustCollectStore) {
 
       // Collect request ended
       debug('trace event (ss); request: %s, request finished', requestId)
-      agent.serverSend(collectorDataBag)
+      agent.serverSend(serverSendData)
       delete mustCollectStore[requestId]
     }
 

lib/instrumentations/core/http/server.spec.js

@@ -57,7 +57,12 @@ describe('The http.Server.prototype wrapper module', function () {
       serverReceive: this.sandbox.spy(),
       bind: function () {
         return this.sandbox.spy()
-      }.bind(this)
+      }.bind(this),
+      clearTransaction: this.sandbox.spy(),
+      rpmMetrics: {
+        addResponseTime: this.sandbox.spy(),
+        addStatusCode: this.sandbox.spy()
+      }
     }
   })
 
@@ -97,6 +102,48 @@ describe('The http.Server.prototype wrapper module', function () {
       })
     })
 
+    it('skips the request if the statusCode is a match', function () {
+      config.ignoreStatusCodes = [
+        401
+      ]
+      var s = server(original, agent, mustCollectStore)
+      var writeHeadSpy = this.sandbox.spy()
+      var setHeaderSpy = this.sandbox.spy()
+      var cb
+
+      var request = {
+        headers: {
+          host: 'localhost'
+        },
+        pathname: '/',
+        url: '/healthcheck',
+        method: 'POST'
+      }
+      var response = {
+        writeHead: writeHeadSpy,
+        // it is ugly, let's make it better later
+        once: function (name, _cb) {
+          if (name === 'finish') {
+            cb = _cb
+          }
+        },
+        setHeader: setHeaderSpy,
+        statusCode: 401
+      }
+
+      this.sandbox.stub(microtime, 'now').returns(12345678)
+
+      s(request, response)
+
+      response.writeHead()
+      cb()
+
+      expect(agent.clearTransaction).to.be.calledWith(transactionId)
+      expect(agent.rpmMetrics.addResponseTime).to.be.calledWith(0)
+      expect(agent.rpmMetrics.addStatusCode).to.be.calledWith(401)
+      expect(agent.serverSend).not.to.have.been.called
+    })
+
     it('skips requests if there is an *', function () {
       config.ignoreHeaders = {
         'user-agent': '*'
@@ -177,6 +224,8 @@ describe('The http.Server.prototype wrapper module', function () {
 
       expect(setHeaderSpy).to.be.calledWith('x-server-send', 12345678)
       expect(setHeaderSpy).to.be.calledWith('x-parent', 0)
+      expect(agent.rpmMetrics.addResponseTime).to.be.calledWith(0)
+      expect(agent.rpmMetrics.addStatusCode).to.be.calledWith(statusCode)
       expect(writeHeadSpy).to.be.calledOnce
     })
 
@@ -244,6 +293,8 @@ describe('The http.Server.prototype wrapper module', function () {
       expect(setHeaderSpy).to.be.calledWith('x-parent', 0)
       expect(setHeaderSpy).to.be.calledWith('x-span-id', spanId)
       expect(setHeaderSpy).to.be.calledWith('x-must-collect', '1')
+      expect(agent.rpmMetrics.addResponseTime).to.be.calledWith(0)
+      expect(agent.rpmMetrics.addStatusCode).to.be.calledWith(statusCode)
       expect(writeHeadSpy).to.be.calledOnce
     })
   })