fix(sampling): unify samping method

Author: peteyycz

lib/providers/httpTransaction/index.js

@@ -146,7 +146,7 @@ HttpTransaction.prototype.onClientReceive = function (data) {
   var trace = this._initTrace(data)
 
   if (data.err) {
-    trace.isSampled = true
+    trace.isForceSampled = true
   }
 
   trace.events.push({
@@ -172,11 +172,9 @@ HttpTransaction.prototype.onServerSend = function (data) {
     type: HttpTransaction.SERVER_SEND
   })
 
-  var isSampled = trace.isSampled || (1 / this.sampleRate) > Math.random()
-  if (data.mustCollect || isSampled) {
-    trace.isForceSampled = !!data.mustCollect
-    delete trace.isSampled
-
+  trace.isSampled = (1 / this.sampleRate) > Math.random()
+  trace.isForceSampled = trace.isForceSampled || !!data.mustCollect
+  if (trace.isForceSampled || trace.isSampled) {
     this.traces.push(trace)
   }
 

lib/providers/httpTransaction/index.spec.js

@@ -392,6 +392,7 @@ describe('The HttpTransaction module', function () {
         span: url,
         host: host,
         trace: id,
+        isSampled: true,
         isForceSampled: false,
         service: service,
         statusCode: 301,