Exclude feeder from service time

build.sbt

@@ -1,6 +1,6 @@
 import scala.sys.process._
 
-val gatlingVersion = "2.3.0"
+val gatlingVersion = "2.3.1"
 
 scalacOptions += "-target:jvm-1.8"
 

src/main/scala/com/datastax/gatling/plugin/request/CqlRequestAction.scala

@@ -61,18 +61,10 @@ class CqlRequestAction(val name: String,
   }
 
   def sendQuery(session: Session): Unit = {
-    val enableCO = Boolean.getBoolean("gatling.dse.plugin.measure_service_time")
-    val responseTimeBuilder: ResponseTimeBuilder = if (enableCO) {
-      // The throughput checker is useless in CO affected scenarios since throughput is not known in advance
-      COAffectedResponseTime.startingAt(System.nanoTime())
-    } else {
-      ThroughputVerifier.checkForGatlingOverloading(session, gatlingTimingSource)
-      GatlingResponseTime.startedByGatling(session, gatlingTimingSource)
-    }
     val stmt = dseAttributes.statement.buildFromSession(session)
 
     stmt.onFailure(err => {
-      val responseTime: ResponseTime = responseTimeBuilder.build()
+      val responseTime = new ServiceTime(0, 0)
       val logUuid = UUID.randomUUID.toString
       val tagString = if (session.groupHierarchy.nonEmpty) session.groupHierarchy.mkString("/") + "/" + dseAttributes.tag else dseAttributes.tag
 
@@ -84,6 +76,8 @@ class CqlRequestAction(val name: String,
     })
 
     stmt.onSuccess({ stmt =>
+      val responseTimeBuilder = ResponseTimeBuilder.newResponseTimeBuilder(session, gatlingTimingSource)
+
       // global options
       dseAttributes.cl.map(stmt.setConsistencyLevel)
       dseAttributes.userOrRole.map(stmt.executingAs)

src/main/scala/com/datastax/gatling/plugin/request/GraphRequestAction.scala

@@ -61,18 +61,10 @@ class GraphRequestAction(val name: String,
 
 
   def sendQuery(session: Session): Unit = {
-    val enableCO = Boolean.getBoolean("gatling.dse.plugin.measure_service_time")
-    val responseTimeBuilder: ResponseTimeBuilder = if (enableCO) {
-      // The throughput checker is useless in CO affected scenarios since throughput is not known in advance
-      COAffectedResponseTime.startingAt(System.nanoTime())
-    } else {
-      ThroughputVerifier.checkForGatlingOverloading(session, gatlingTimingSource)
-      GatlingResponseTime.startedByGatling(session, gatlingTimingSource)
-    }
     val stmt = dseAttributes.statement.buildFromSession(session)
 
     stmt.onFailure(err => {
-      val responseTime = responseTimeBuilder.build()
+      val responseTime = new ServiceTime(0, 0)
       val logUuid = UUID.randomUUID.toString
       val tagString = if (session.groupHierarchy.nonEmpty) session.groupHierarchy.mkString("/") + "/" + dseAttributes.tag else dseAttributes.tag
 
@@ -84,6 +76,8 @@ class GraphRequestAction(val name: String,
     })
 
     stmt.onSuccess({ gStmt =>
+      val responseTimeBuilder = ResponseTimeBuilder.newResponseTimeBuilder(session, gatlingTimingSource)
+
       // global options
       dseAttributes.cl.map(gStmt.setConsistencyLevel)
       dseAttributes.defaultTimestamp.map(gStmt.setDefaultTimestamp)

src/main/scala/com/datastax/gatling/plugin/utils/ResponseTime.scala

@@ -9,6 +9,8 @@ package com.datastax.gatling.plugin.utils
 import java.util.concurrent.TimeUnit
 import java.util.concurrent.TimeUnit.{MILLISECONDS, NANOSECONDS}
 
+import com.datastax.gatling.plugin.request.ThroughputVerifier
+import com.typesafe.scalalogging.StrictLogging
 import io.gatling.commons.util.ClockSingleton
 import io.gatling.core.Predef.Session
 import io.gatling.core.stats.message.ResponseTimings
@@ -21,6 +23,32 @@ trait ResponseTime {
   def startTimeIn(targetTimeUnit: TimeUnit): Long
 }
 
+object ResponseTimeBuilder extends StrictLogging {
+  val measureServiceTime: Boolean = {
+    if (java.lang.Boolean.getBoolean("gatling.dse.plugin.measure_service_time")) {
+      logger.info("Gatling DSE plugin is configured to measure service time")
+      true
+    } else {
+      logger.info("Gatling DSE plugin is configured to measure response time")
+      false
+    }
+  }
+
+  def newResponseTimeBuilder(session: Session, gatlingTimingSource: GatlingTimingSource): ResponseTimeBuilder = {
+    if (measureServiceTime) {
+      // The throughput checker is useless in CO affected scenarios since throughput is not known in advance
+      // Also, measuring service time MUST exclude the time spent in the feeder.
+      // So it makes sense to take the "start" measurement from `nanoTime()` here.
+      ServiceTime.startingAt(System.nanoTime())
+    } else {
+      // We trust Gatling for the user creation time when we measure response time.
+      // Therefore, the response time builder can be built anywhere.
+      ThroughputVerifier.checkForGatlingOverloading(session, gatlingTimingSource)
+      GatlingResponseTime.startedByGatling(session, gatlingTimingSource)
+    }
+  }
+}
+
 trait ResponseTimeBuilder {
   def build(): ResponseTime
 }
@@ -63,12 +91,12 @@ case class GatlingResponseTime(session: Session, timingSource: TimingSource)
       session.startDate + NANOSECONDS.toMillis(latencyInNanos))
 }
 
-object COAffectedResponseTime {
+object ServiceTime {
   def startingAt(startNanos: Long): ResponseTimeBuilder =
-    () => COAffectedResponseTime(startNanos, System.nanoTime())
+    () => ServiceTime(startNanos, System.nanoTime())
 }
 
-case class COAffectedResponseTime(startNanos: Long, endNanos: Long)
+case class ServiceTime(startNanos: Long, endNanos: Long)
   extends ResponseTime {
   override def latencyIn(targetTimeUnit: TimeUnit): Long =
     targetTimeUnit.convert(endNanos - startNanos, NANOSECONDS)