Adds ability to receive debug flag from Finagle. If the debug flag is…

… set on a span we ensure it is stored. This allows developers to force tracing on a request

Author: @johanoskarsson
Fixes #86
URL: #86

zipkin-common/src/main/scala/com/twitter/zipkin/common/Span.scala

@@ -21,7 +21,7 @@ import com.twitter.zipkin.Constants
 /**
  * A span represents one RPC request. A trace is made up of many spans.
  *
- * A span can contain multiple annotations, some are always incuded such as
+ * A span can contain multiple annotations, some are always included such as
  * Client send -> Server received -> Server send -> Client receive.
  *
  * Some are created by users, describing application specific information,
@@ -30,7 +30,7 @@ import com.twitter.zipkin.Constants
 object Span {
 
   def apply(span: Span): Span = Span(span.traceId, span.name, span.id,
-    span.parentId, span.annotations, span.binaryAnnotations)
+    span.parentId, span.annotations, span.binaryAnnotations, span.debug)
 }
 
 /**
@@ -42,9 +42,10 @@ object Span {
  * some fixed ones from the tracing framework
  * @param binaryAnnotations  binary annotations, can contain more detailed information such as
  * serialized objects
+ * @param debug if this is set we will make sure this span is stored, no matter what the samplers want
  */
 case class Span(traceId: Long, name: String, id: Long, parentId: Option[Long],
-                 annotations: List[Annotation], binaryAnnotations: Seq[BinaryAnnotation]) {
+                 annotations: List[Annotation], binaryAnnotations: Seq[BinaryAnnotation], debug: Boolean = false) {
   /**
    * Order annotations by timestamp.
    */
@@ -96,7 +97,7 @@ case class Span(traceId: Long, name: String, id: Long, parentId: Option[Long],
 
     new Span(traceId, selectedName, id, parentId,
       annotations ++ mergeFrom.annotations,
-      binaryAnnotations ++ mergeFrom.binaryAnnotations)
+      binaryAnnotations ++ mergeFrom.binaryAnnotations, debug | mergeFrom.debug)
   }
 
   /**

zipkin-common/src/test/scala/com/twitter/zipkin/common/SpanSpec.scala

@@ -52,9 +52,9 @@ class SpanSpec extends Specification {
       val ann1 = Annotation(1, "value1", Some(Endpoint(1, 2, "service")))
       val ann2 = Annotation(2, "value2", Some(Endpoint(3, 4, "service")))
 
-      val span1 = Span(12345, "", 666, None, List(ann1), Nil)
-      val span2 = Span(12345, "methodcall", 666, None, List(ann2), Nil)
-      val expectedSpan = Span(12345, "methodcall", 666, None, List(ann1, ann2), Nil)
+      val span1 = Span(12345, "", 666, None, List(ann1), Nil, true)
+      val span2 = Span(12345, "methodcall", 666, None, List(ann2), Nil, false)
+      val expectedSpan = Span(12345, "methodcall", 666, None, List(ann1, ann2), Nil, true)
       val actualSpan = span1.mergeSpan(span2)
       actualSpan mustEqual expectedSpan
     }

zipkin-scribe/src/test/scala/com/twitter/zipkin/collector/ScribeCollectorServiceSpec.scala

@@ -38,7 +38,7 @@ class ScribeCollectorServiceSpec extends Specification with JMocker with ClassMo
 
   val wrongCatList = List(gen.LogEntry("wrongcat", serializer.toString(ThriftAdapter(validSpan))))
 
-  val base64 = "CgABAAAAAAAAAHsLAAMAAAADYm9vCgAEAAAAAAAAAcgPAAYMAAAAAQoAAQAAAAAAAAABCwACAAAAA2JhaAAPAAgMAAAAAAA="
+  val base64 = "CgABAAAAAAAAAHsLAAMAAAADYm9vCgAEAAAAAAAAAcgPAAYMAAAAAQoAAQAAAAAAAAABCwACAAAAA2JhaAAPAAgMAAAAAAIACQAA"
 
   val queue = mock[WriteQueue[Seq[String]]]
   val zkSampleRateConfig = mock[AdjustableRateConfig]

zipkin-scrooge/src/main/scala/com/twitter/zipkin/adapter/ThriftAdapter.scala

@@ -108,13 +108,13 @@ object ThriftAdapter extends Adapter {
       case b => b.map { this(_) }
     }
 
-    new Span(s.traceId, s.name, s.id, s.parentId, annotations, binaryAnnotations)
+    new Span(s.traceId, s.name, s.id, s.parentId, annotations, binaryAnnotations, s.debug)
   }
 
   /* Span to Thrift */
   def apply(s: Span): spanType = {
     gen.Span(s.traceId, s.name, s.id, s.parentId, s.annotations.map { this(_) },
-      s.binaryAnnotations.map { this(_) })
+      s.binaryAnnotations.map { this(_) }, s.debug)
   }
 
   /* TraceSummary from Thrift */

zipkin-server/src/main/scala/com/twitter/zipkin/collector/processor/SamplerProcessorFilter.scala

@@ -29,7 +29,14 @@ class SamplerProcessorFilter(sampler: GlobalSampler) extends ProcessorFilter[Seq
     spans.flatMap { span =>
       span.serviceNames.foreach { name => Stats.incr("received_" + name) }
 
-      if (sampler(span.traceId)) {
+      /**
+       * If the span was created with debug mode on we guarantee that it will be
+       * stored no matter what our sampler tells us
+       */
+      if (span.debug) {
+        Stats.incr("debugflag")
+        Some(span)
+      } else if (sampler(span.traceId)) {
         Some(span)
       } else {
         None

zipkin-server/src/main/scala/com/twitter/zipkin/collector/sampler/GlobalSampler.scala

@@ -36,6 +36,20 @@ trait GlobalSampler {
    * True: drop trace on the floor
    * False: process trace
    */
-  def apply(traceId: Long) : Boolean = false
+  def apply(traceId: Long): Boolean = false
 
 }
+
+/**
+ * None shall pass! Drop all the trace data.
+ */
+object NullGlobalSampler extends GlobalSampler {
+  override def apply(traceId: Long) = false
+}
+
+/**
+ * Let everything through.
+ */
+object EverythingGlobalSampler extends GlobalSampler {
+  override def apply(traceId: Long) = true
+}

zipkin-server/src/test/scala/com/twitter/zipkin/collector/processor/SamplerProcessorFilterSpec.scala

@@ -0,0 +1,50 @@
+package com.twitter.zipkin.collector.processor
+
+/*
+ * Copyright 2012 Twitter Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+
+import org.specs.Specification
+import com.twitter.zipkin.gen
+import com.twitter.zipkin.common.{Span, Endpoint, Annotation}
+import com.twitter.ostrich.stats.{Histogram, Distribution, Stats}
+import com.twitter.zipkin.collector.sampler.{EverythingGlobalSampler, NullGlobalSampler}
+
+class SamplerProcessorFilterSpec extends Specification {
+
+  "SamplerProcessorFilter" should {
+    "let the span pass if debug flag is set" in {
+      val span = Span(12345, "methodcall", 666, None, List(), Nil, true)
+      val spans = Seq(span)
+      val samplerProcessor = new SamplerProcessorFilter(NullGlobalSampler)
+      samplerProcessor(spans) mustEqual spans
+    }
+
+    "let the span pass if debug flag false and sampler says yes" in {
+      val span = Span(12345, "methodcall", 666, None, List(), Nil, false)
+      val spans = Seq(span)
+      val samplerProcessor = new SamplerProcessorFilter(EverythingGlobalSampler)
+      samplerProcessor(spans) mustEqual spans
+    }
+
+    "don't let the span pass if debug flag false and sampler says no" in {
+      val span = Span(12345, "methodcall", 666, None, List(), Nil, false)
+      val spans = Seq(span)
+      val samplerProcessor = new SamplerProcessorFilter(NullGlobalSampler)
+      samplerProcessor(spans) mustEqual Seq()
+    }
+  }
+}

zipkin-test/src/test/resources/TestCollector.scala

@@ -16,7 +16,7 @@
 import com.twitter.zipkin.config._
 import com.twitter.zipkin.config.sampler.NullAdaptiveSamplerConfig
 import com.twitter.zipkin.config.zookeeper.ZooKeeperConfig
-import com.twitter.zipkin.collector.sampler.GlobalSampler
+import com.twitter.zipkin.collector.sampler.{GlobalSampler, EverythingGlobalSampler}
 import com.twitter.conversions.time._
 import com.twitter.logging.LoggerFactory
 import com.twitter.logging.config._
@@ -64,9 +64,7 @@ new ScribeZipkinCollectorConfig {
   override def adaptiveSamplerConfig = new NullAdaptiveSamplerConfig {}
 
   // sample it all
-  override def globalSampler: GlobalSampler = new GlobalSampler() {
-    override def apply(traceId: Long) : Boolean = true
-  }
+  override def globalSampler: GlobalSampler = EverythingGlobalSampler
 
   def zkConfig = new ZooKeeperConfig {
     servers = List("localhost:2181")

zipkin-thrift/src/main/thrift/zipkinCore.thrift

@@ -53,4 +53,6 @@ struct Span {
   5: optional i64 parent_id,                // parent span id
   6: list<Annotation> annotations, // list of all annotations/events that occured
   8: list<BinaryAnnotation> binary_annotations // any binary annotations
+  9: optional bool debug = 0       // if true, we DEMAND that this span passes all samplers
 }
+