[SPARK-7977] [BUILD] Disallowing println

Author: Jonathan Alter <jonalter@users.noreply.github.com>

Closes #7093 from jonalter/SPARK-7977 and squashes the following commits:

ccd44cc [Jonathan Alter] Changed println to log in ThreadingSuite
7fcac3e [Jonathan Alter] Reverting to println in ThreadingSuite
10724b6 [Jonathan Alter] Changing some printlns to logs in tests
eeec1e7 [Jonathan Alter] Merge branch 'master' of github.com:apache/spark into SPARK-7977
0b1dcb4 [Jonathan Alter] More println cleanup
aedaf80 [Jonathan Alter] Merge branch 'master' of github.com:apache/spark into SPARK-7977
925fd98 [Jonathan Alter] Merge branch 'master' of github.com:apache/spark into SPARK-7977
0c16fa3 [Jonathan Alter] Replacing some printlns with logs
45c7e05 [Jonathan Alter] Merge branch 'master' of github.com:apache/spark into SPARK-7977
5c8e283 [Jonathan Alter] Allowing println in audit-release examples
5b50da1 [Jonathan Alter] Allowing printlns in example files
ca4b477 [Jonathan Alter] Merge branch 'master' of github.com:apache/spark into SPARK-7977
83ab635 [Jonathan Alter] Fixing new printlns
54b131f [Jonathan Alter] Merge branch 'master' of github.com:apache/spark into SPARK-7977
1cd8a81 [Jonathan Alter] Removing some unnecessary comments and printlns
b837c3a [Jonathan Alter] Disallowing println

39 files changed, 147 insertions, 78 deletions

diff --git a/core/src/main/scala/org/apache/spark/Logging.scala b/core/src/main/scala/org/apache/spark/Logging.scala
index 7fcb7830e7..87ab099267 100644
--- a/core/src/main/scala/org/apache/spark/Logging.scala
+++ b/core/src/main/scala/org/apache/spark/Logging.scala
@@ -121,6 +121,7 @@ trait Logging {
     if (usingLog4j12) {
       val log4j12Initialized = LogManager.getRootLogger.getAllAppenders.hasMoreElements
       if (!log4j12Initialized) {
+        // scalastyle:off println
         if (Utils.isInInterpreter) {
           val replDefaultLogProps = "org/apache/spark/log4j-defaults-repl.properties"
           Option(Utils.getSparkClassLoader.getResource(replDefaultLogProps)) match {
@@ -141,6 +142,7 @@ trait Logging {
               System.err.println(s"Spark was unable to load $defaultLogProps")
           }
         }
+        // scalastyle:on println
       }
     }
     Logging.initialized = true
diff --git a/core/src/main/scala/org/apache/spark/api/r/RBackend.scala b/core/src/main/scala/org/apache/spark/api/r/RBackend.scala
index 1a5f2bca26..b7e72d4d0e 100644
--- a/core/src/main/scala/org/apache/spark/api/r/RBackend.scala
+++ b/core/src/main/scala/org/apache/spark/api/r/RBackend.scala
@@ -95,7 +95,9 @@ private[spark] class RBackend {
 private[spark] object RBackend extends Logging {
   def main(args: Array[String]): Unit = {
     if (args.length < 1) {
+      // scalastyle:off println
       System.err.println("Usage: RBackend <tempFilePath>")
+      // scalastyle:on println
       System.exit(-1)
     }
     val sparkRBackend = new RBackend()
diff --git a/core/src/main/scala/org/apache/spark/api/r/RRDD.scala b/core/src/main/scala/org/apache/spark/api/r/RRDD.scala
index 524676544d..ff1702f7de 100644
--- a/core/src/main/scala/org/apache/spark/api/r/RRDD.scala
+++ b/core/src/main/scala/org/apache/spark/api/r/RRDD.scala
@@ -161,7 +161,9 @@ private abstract class BaseRRDD[T: ClassTag, U: ClassTag](
               dataOut.write(elem.asInstanceOf[Array[Byte]])
             } else if (deserializer == SerializationFormats.STRING) {
               // write string(for StringRRDD)
+              // scalastyle:off println
               printOut.println(elem)
+              // scalastyle:on println
             }
           }
 
diff --git a/core/src/main/scala/org/apache/spark/deploy/Client.scala b/core/src/main/scala/org/apache/spark/deploy/Client.scala
index 71f7e21291..f03875a3e8 100644
--- a/core/src/main/scala/org/apache/spark/deploy/Client.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/Client.scala
@@ -118,26 +118,26 @@ private class ClientEndpoint(
   def pollAndReportStatus(driverId: String) {
     // Since ClientEndpoint is the only RpcEndpoint in the process, blocking the event loop thread
     // is fine.
-    println("... waiting before polling master for driver state")
+    logInfo("... waiting before polling master for driver state")
     Thread.sleep(5000)
-    println("... polling master for driver state")
+    logInfo("... polling master for driver state")
     val statusResponse =
       activeMasterEndpoint.askWithRetry[DriverStatusResponse](RequestDriverStatus(driverId))
     statusResponse.found match {
       case false =>
-        println(s"ERROR: Cluster master did not recognize $driverId")
+        logError(s"ERROR: Cluster master did not recognize $driverId")
         System.exit(-1)
       case true =>
-        println(s"State of $driverId is ${statusResponse.state.get}")
+        logInfo(s"State of $driverId is ${statusResponse.state.get}")
         // Worker node, if present
         (statusResponse.workerId, statusResponse.workerHostPort, statusResponse.state) match {
           case (Some(id), Some(hostPort), Some(DriverState.RUNNING)) =>
-            println(s"Driver running on $hostPort ($id)")
+            logInfo(s"Driver running on $hostPort ($id)")
           case _ =>
         }
         // Exception, if present
         statusResponse.exception.map { e =>
-          println(s"Exception from cluster was: $e")
+          logError(s"Exception from cluster was: $e")
           e.printStackTrace()
           System.exit(-1)
         }
@@ -148,7 +148,7 @@ private class ClientEndpoint(
   override def receive: PartialFunction[Any, Unit] = {
 
     case SubmitDriverResponse(master, success, driverId, message) =>
-      println(message)
+      logInfo(message)
       if (success) {
         activeMasterEndpoint = master
         pollAndReportStatus(driverId.get)
@@ -158,7 +158,7 @@ private class ClientEndpoint(
 
 
     case KillDriverResponse(master, driverId, success, message) =>
-      println(message)
+      logInfo(message)
       if (success) {
         activeMasterEndpoint = master
         pollAndReportStatus(driverId)
@@ -169,13 +169,13 @@ private class ClientEndpoint(
 
   override def onDisconnected(remoteAddress: RpcAddress): Unit = {
     if (!lostMasters.contains(remoteAddress)) {
-      println(s"Error connecting to master $remoteAddress.")
+      logError(s"Error connecting to master $remoteAddress.")
       lostMasters += remoteAddress
       // Note that this heuristic does not account for the fact that a Master can recover within
       // the lifetime of this client. Thus, once a Master is lost it is lost to us forever. This
       // is not currently a concern, however, because this client does not retry submissions.
       if (lostMasters.size >= masterEndpoints.size) {
-        println("No master is available, exiting.")
+        logError("No master is available, exiting.")
         System.exit(-1)
       }
     }
@@ -183,18 +183,18 @@ private class ClientEndpoint(
 
   override def onNetworkError(cause: Throwable, remoteAddress: RpcAddress): Unit = {
     if (!lostMasters.contains(remoteAddress)) {
-      println(s"Error connecting to master ($remoteAddress).")
-      println(s"Cause was: $cause")
+      logError(s"Error connecting to master ($remoteAddress).")
+      logError(s"Cause was: $cause")
       lostMasters += remoteAddress
       if (lostMasters.size >= masterEndpoints.size) {
-        println("No master is available, exiting.")
+        logError("No master is available, exiting.")
         System.exit(-1)
       }
     }
   }
 
   override def onError(cause: Throwable): Unit = {
-    println(s"Error processing messages, exiting.")
+    logError(s"Error processing messages, exiting.")
     cause.printStackTrace()
     System.exit(-1)
   }
@@ -209,10 +209,12 @@ private class ClientEndpoint(
  */
 object Client {
   def main(args: Array[String]) {
+    // scalastyle:off println
     if (!sys.props.contains("SPARK_SUBMIT")) {
       println("WARNING: This client is deprecated and will be removed in a future version of Spark")
       println("Use ./bin/spark-submit with \"--master spark://host:port\"")
     }
+    // scalastyle:on println
 
     val conf = new SparkConf()
     val driverArgs = new ClientArguments(args)
diff --git a/core/src/main/scala/org/apache/spark/deploy/ClientArguments.scala b/core/src/main/scala/org/apache/spark/deploy/ClientArguments.scala
index 42d3296062..72cc330a39 100644
--- a/core/src/main/scala/org/apache/spark/deploy/ClientArguments.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/ClientArguments.scala
@@ -72,9 +72,11 @@ private[deploy] class ClientArguments(args: Array[String]) {
       cmd = "launch"
 
       if (!ClientArguments.isValidJarUrl(_jarUrl)) {
+        // scalastyle:off println
         println(s"Jar url '${_jarUrl}' is not in valid format.")
         println(s"Must be a jar file path in URL format " +
           "(e.g. hdfs://host:port/XX.jar, file:///XX.jar)")
+        // scalastyle:on println
         printUsageAndExit(-1)
       }
 
@@ -110,7 +112,9 @@ private[deploy] class ClientArguments(args: Array[String]) {
       |                                  (default: $DEFAULT_SUPERVISE)
       |   -v, --verbose                  Print more debugging output
      """.stripMargin
+    // scalastyle:off println
     System.err.println(usage)
+    // scalastyle:on println
     System.exit(exitCode)
   }
 }
diff --git a/core/src/main/scala/org/apache/spark/deploy/RRunner.scala b/core/src/main/scala/org/apache/spark/deploy/RRunner.scala
index e99779f299..4165740312 100644
--- a/core/src/main/scala/org/apache/spark/deploy/RRunner.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/RRunner.scala
@@ -85,7 +85,9 @@ object RRunner {
       }
       System.exit(returnCode)
     } else {
+      // scalastyle:off println
       System.err.println("SparkR backend did not initialize in " + backendTimeout + " seconds")
+      // scalastyle:on println
       System.exit(-1)
     }
   }
diff --git a/core/src/main/scala/org/apache/spark/deploy/SparkSubmit.scala b/core/src/main/scala/org/apache/spark/deploy/SparkSubmit.scala
index b1d6ec209d..4cec9017b8 100644
--- a/core/src/main/scala/org/apache/spark/deploy/SparkSubmit.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/SparkSubmit.scala
@@ -82,6 +82,7 @@ object SparkSubmit {
 
   private val CLASS_NOT_FOUND_EXIT_STATUS = 101
 
+  // scalastyle:off println
   // Exposed for testing
   private[spark] var exitFn: Int => Unit = (exitCode: Int) => System.exit(exitCode)
   private[spark] var printStream: PrintStream = System.err
@@ -102,11 +103,14 @@ object SparkSubmit {
     printStream.println("Type --help for more information.")
     exitFn(0)
   }
+  // scalastyle:on println
 
   def main(args: Array[String]): Unit = {
     val appArgs = new SparkSubmitArguments(args)
     if (appArgs.verbose) {
+      // scalastyle:off println
       printStream.println(appArgs)
+      // scalastyle:on println
     }
     appArgs.action match {
       case SparkSubmitAction.SUBMIT => submit(appArgs)
@@ -160,7 +164,9 @@ object SparkSubmit {
             // makes the message printed to the output by the JVM not very helpful. Instead,
             // detect exceptions with empty stack traces here, and treat them differently.
             if (e.getStackTrace().length == 0) {
+              // scalastyle:off println
               printStream.println(s"ERROR: ${e.getClass().getName()}: ${e.getMessage()}")
+              // scalastyle:on println
               exitFn(1)
             } else {
               throw e
@@ -178,7 +184,9 @@ object SparkSubmit {
      // to use the legacy gateway if the master endpoint turns out to be not a REST server.
     if (args.isStandaloneCluster && args.useRest) {
       try {
+        // scalastyle:off println
         printStream.println("Running Spark using the REST application submission protocol.")
+        // scalastyle:on println
         doRunMain()
       } catch {
         // Fail over to use the legacy submission gateway
@@ -558,6 +566,7 @@ object SparkSubmit {
       sysProps: Map[String, String],
       childMainClass: String,
       verbose: Boolean): Unit = {
+    // scalastyle:off println
     if (verbose) {
       printStream.println(s"Main class:\n$childMainClass")
       printStream.println(s"Arguments:\n${childArgs.mkString("\n")}")
@@ -565,6 +574,7 @@ object SparkSubmit {
       printStream.println(s"Classpath elements:\n${childClasspath.mkString("\n")}")
       printStream.println("\n")
     }
+    // scalastyle:on println
 
     val loader =
       if (sysProps.getOrElse("spark.driver.userClassPathFirst", "false").toBoolean) {
@@ -592,8 +602,10 @@ object SparkSubmit {
       case e: ClassNotFoundException =>
         e.printStackTrace(printStream)
         if (childMainClass.contains("thriftserver")) {
+          // scalastyle:off println
           printStream.println(s"Failed to load main class $childMainClass.")
           printStream.println("You need to build Spark with -Phive and -Phive-thriftserver.")
+          // scalastyle:on println
         }
         System.exit(CLASS_NOT_FOUND_EXIT_STATUS)
     }
@@ -766,7 +778,9 @@ private[spark] object SparkSubmitUtils {
         brr.setRoot(repo)
         brr.setName(s"repo-${i + 1}")
         cr.add(brr)
+        // scalastyle:off println
         printStream.println(s"$repo added as a remote repository with the name: ${brr.getName}")
+        // scalastyle:on println
       }
     }
 
@@ -829,7 +843,9 @@ private[spark] object SparkSubmitUtils {
       val ri = ModuleRevisionId.newInstance(mvn.groupId, mvn.artifactId, mvn.version)
       val dd = new DefaultDependencyDescriptor(ri, false, false)
       dd.addDependencyConfiguration(ivyConfName, ivyConfName)
+      // scalastyle:off println
       printStream.println(s"${dd.getDependencyId} added as a dependency")
+      // scalastyle:on println
       md.addDependency(dd)
     }
   }
@@ -896,9 +912,11 @@ private[spark] object SparkSubmitUtils {
             ivySettings.setDefaultCache(new File(alternateIvyCache, "cache"))
             new File(alternateIvyCache, "jars")
           }
+        // scalastyle:off println
         printStream.println(
           s"Ivy Default Cache set to: ${ivySettings.getDefaultCache.getAbsolutePath}")
         printStream.println(s"The jars for the packages stored in: $packagesDirectory")
+        // scalastyle:on println
         // create a pattern matcher
         ivySettings.addMatcher(new GlobPatternMatcher)
         // create the dependency resolvers
diff --git a/core/src/main/scala/org/apache/spark/deploy/SparkSubmitArguments.scala b/core/src/main/scala/org/apache/spark/deploy/SparkSubmitArguments.scala
index 6e3c0b21b3..ebb39c354d 100644
--- a/core/src/main/scala/org/apache/spark/deploy/SparkSubmitArguments.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/SparkSubmitArguments.scala
@@ -79,6 +79,7 @@ private[deploy] class SparkSubmitArguments(args: Seq[String], env: Map[String, S
   /** Default properties present in the currently defined defaults file. */
   lazy val defaultSparkProperties: HashMap[String, String] = {
     val defaultProperties = new HashMap[String, String]()
+    // scalastyle:off println
     if (verbose) SparkSubmit.printStream.println(s"Using properties file: $propertiesFile")
     Option(propertiesFile).foreach { filename =>
       Utils.getPropertiesFromFile(filename).foreach { case (k, v) =>
@@ -86,6 +87,7 @@ private[deploy] class SparkSubmitArguments(args: Seq[String], env: Map[String, S
         if (verbose) SparkSubmit.printStream.println(s"Adding default property: $k=$v")
       }
     }
+    // scalastyle:on println
     defaultProperties
   }
 
@@ -452,6 +454,7 @@ private[deploy] class SparkSubmitArguments(args: Seq[String], env: Map[String, S
   }
 
   private def printUsageAndExit(exitCode: Int, unknownParam: Any = null): Unit = {
+    // scalastyle:off println
     val outStream = SparkSubmit.printStream
     if (unknownParam != null) {
       outStream.println("Unknown/unsupported param " + unknownParam)
@@ -541,6 +544,7 @@ private[deploy] class SparkSubmitArguments(args: Seq[String], env: Map[String, S
       outStream.println("CLI options:")
       outStream.println(getSqlShellOptions())
     }
+    // scalastyle:on println
 
     SparkSubmit.exitFn(exitCode)
   }
diff --git a/core/src/main/scala/org/apache/spark/deploy/client/TestExecutor.scala b/core/src/main/scala/org/apache/spark/deploy/client/TestExecutor.scala
index c5ac45c673..a98b1fa8f8 100644
--- a/core/src/main/scala/org/apache/spark/deploy/client/TestExecutor.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/client/TestExecutor.scala
@@ -19,7 +19,9 @@ package org.apache.spark.deploy.client
 
 private[spark] object TestExecutor {
   def main(args: Array[String]) {
+    // scalastyle:off println
     println("Hello world!")
+    // scalastyle:on println
     while (true) {
       Thread.sleep(1000)
     }
diff --git a/core/src/main/scala/org/apache/spark/deploy/history/HistoryServerArguments.scala b/core/src/main/scala/org/apache/spark/deploy/history/HistoryServerArguments.scala
index 4692d22651..18265df9fa 100644
--- a/core/src/main/scala/org/apache/spark/deploy/history/HistoryServerArguments.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/history/HistoryServerArguments.scala
@@ -56,6 +56,7 @@ private[history] class HistoryServerArguments(conf: SparkConf, args: Array[Strin
    Utils.loadDefaultSparkProperties(conf, propertiesFile)
 
   private def printUsageAndExit(exitCode: Int) {
+    // scalastyle:off println
     System.err.println(
       """
       |Usage: HistoryServer [options]
@@ -84,6 +85,7 @@ private[history] class HistoryServerArguments(conf: SparkConf, args: Array[Strin
       |  spark.history.fs.updateInterval    How often to reload log data from storage
       |                                     (in seconds, default: 10)
       |""".stripMargin)
+    // scalastyle:on println
     System.exit(exitCode)
   }
 
diff --git a/core/src/main/scala/org/apache/spark/deploy/master/MasterArguments.scala b/core/src/main/scala/org/apache/spark/deploy/master/MasterArguments.scala
index 435b9b12f8..44cefbc77f 100644
--- a/core/src/main/scala/org/apache/spark/deploy/master/MasterArguments.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/master/MasterArguments.scala
@@ -85,6 +85,7 @@ private[master] class MasterArguments(args: Array[String], conf: SparkConf) {
    * Print usage and exit JVM with the given exit code.
    */
   private def printUsageAndExit(exitCode: Int) {
+    // scalastyle:off println
     System.err.println(
       "Usage: Master [options]\n" +
       "\n" +
@@ -95,6 +96,7 @@ private[master] class MasterArguments(args: Array[String], conf: SparkConf) {
       "  --webui-port PORT      Port for web UI (default: 8080)\n" +
       "  --properties-file FILE Path to a custom Spark properties file.\n" +
       "                         Default is conf/spark-defaults.conf.")
+    // scalastyle:on println
     System.exit(exitCode)
   }
 }
diff --git a/core/src/main/scala/org/apache/spark/deploy/mesos/MesosClusterDispatcherArguments.scala b/core/src/main/scala/org/apache/spark/deploy/mesos/MesosClusterDispatcherArguments.scala
index 894cb78d85..5accaf78d0 100644
--- a/core/src/main/scala/org/apache/spark/deploy/mesos/MesosClusterDispatcherArguments.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/mesos/MesosClusterDispatcherArguments.scala
@@ -54,7 +54,9 @@ private[mesos] class MesosClusterDispatcherArguments(args: Array[String], conf:
 
     case ("--master" | "-m") :: value :: tail =>
       if (!value.startsWith("mesos://")) {
+        // scalastyle:off println
         System.err.println("Cluster dispatcher only supports mesos (uri begins with mesos://)")
+        // scalastyle:on println
         System.exit(1)
       }
       masterUrl = value.stripPrefix("mesos://")
@@ -73,7 +75,9 @@ private[mesos] class MesosClusterDispatcherArguments(args: Array[String], conf:
 
     case Nil => {
       if (masterUrl == null) {
+        // scalastyle:off println
         System.err.println("--master is required")
+        // scalastyle:on println
         printUsageAndExit(1)
       }
     }
@@ -83,6 +87,7 @@ private[mesos] class MesosClusterDispatcherArguments(args: Array[String], conf:
   }
 
   private def printUsageAndExit(exitCode: Int): Unit = {
+    // scalastyle:off println
     System.err.println(
       "Usage: MesosClusterDispatcher [options]\n" +
         "\n" +
@@ -96,6 +101,7 @@ private[mesos] class MesosClusterDispatcherArguments(args: Array[String], conf:
         "                          Zookeeper for persistence\n" +
         "  --properties-file FILE  Path to a custom Spark properties file.\n" +
         "                          Default is conf/spark-defaults.conf.")
+    // scalastyle:on println
     System.exit(exitCode)
   }
 }
diff --git a/core/src/main/scala/org/apache/spark/deploy/worker/DriverWrapper.scala b/core/src/main/scala/org/apache/spark/deploy/worker/DriverWrapper.scala
index d1a12b01e7..2d6be3042c 100644
--- a/core/src/main/scala/org/apache/spark/deploy/worker/DriverWrapper.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/worker/DriverWrapper.scala
@@ -60,7 +60,9 @@ object DriverWrapper {
         rpcEnv.shutdown()
 
       case _ =>
+        // scalastyle:off println
         System.err.println("Usage: DriverWrapper <workerUrl> <userJar> <driverMainClass> [options]")
+        // scalastyle:on println
         System.exit(-1)
     }
   }
diff --git a/core/src/main/scala/org/apache/spark/deploy/worker/WorkerArguments.scala b/core/src/main/scala/org/apache/spark/deploy/worker/WorkerArguments.scala
index 1d2ecab517..e89d076802 100644
--- a/core/src/main/scala/org/apache/spark/deploy/worker/WorkerArguments.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/worker/WorkerArguments.scala
@@ -121,6 +121,7 @@ private[worker] class WorkerArguments(args: Array[String], conf: SparkConf) {
    * Print usage and exit JVM with the given exit code.
    */
   def printUsageAndExit(exitCode: Int) {
+    // scalastyle:off println
     System.err.println(
       "Usage: Worker [options] <master>\n" +
       "\n" +
@@ -136,6 +137,7 @@ private[worker] class WorkerArguments(args: Array[String], conf: SparkConf) {
       "  --webui-port PORT        Port for web UI (default: 8081)\n" +
       "  --properties-file FILE   Path to a custom Spark properties file.\n" +
       "                           Default is conf/spark-defaults.conf.")
+    // scalastyle:on println
     System.exit(exitCode)
   }
 
@@ -160,7 +162,9 @@ private[worker] class WorkerArguments(args: Array[String], conf: SparkConf) {
     } catch {
       case e: Exception => {
         totalMb = 2*1024
+        // scalastyle:off println
         System.out.println("Failed to get total physical memory. Using " + totalMb + " MB")
+        // scalastyle:on println
       }
     }
     // Leave out 1 GB for the operating system, but don't return a negative memory size
diff --git a/core/src/main/scala/org/apache/spark/executor/CoarseGrainedExecutorBackend.scala b/core/src/main/scala/org/apache/spark/executor/CoarseGrainedExecutorBackend.scala
index 34d4cfdca7..fcd76ec527 100644
--- a/core/src/main/scala/org/apache/spark/executor/CoarseGrainedExecutorBackend.scala
+++ b/core/src/main/scala/org/apache/spark/executor/CoarseGrainedExecutorBackend.scala
@@ -235,7 +235,9 @@ private[spark] object CoarseGrainedExecutorBackend extends Logging {
           argv = tail
         case Nil =>
         case tail =>
+          // scalastyle:off println
           System.err.println(s"Unrecognized options: ${tail.mkString(" ")}")
+          // scalastyle:on println
           printUsageAndExit()
       }
     }
@@ -249,6 +251,7 @@ private[spark] object CoarseGrainedExecutorBackend extends Logging {
   }
 
   private def printUsageAndExit() = {
+    // scalastyle:off println
     System.err.println(
       """
       |"Usage: CoarseGrainedExecutorBackend [options]
@@ -262,6 +265,7 @@ private[spark] object CoarseGrainedExecutorBackend extends Logging {
       |   --worker-url <workerUrl>
       |   --user-class-path <url>
       |""".stripMargin)
+    // scalastyle:on println
     System.exit(1)
   }
 
diff --git a/core/src/main/scala/org/apache/spark/input/FixedLengthBinaryInputFormat.scala b/core/src/main/scala/org/apache/spark/input/FixedLengthBinaryInputFormat.scala
index c219d21fbe..532850dd57 100644
--- a/core/src/main/scala/org/apache/spark/input/FixedLengthBinaryInputFormat.scala
+++ b/core/src/main/scala/org/apache/spark/input/FixedLengthBinaryInputFormat.scala
@@ -21,6 +21,8 @@ import org.apache.hadoop.fs.Path
 import org.apache.hadoop.io.{BytesWritable, LongWritable}
 import org.apache.hadoop.mapreduce.lib.input.FileInputFormat
 import org.apache.hadoop.mapreduce.{InputSplit, JobContext, RecordReader, TaskAttemptContext}
+
+import org.apache.spark.Logging
 import org.apache.spark.deploy.SparkHadoopUtil
 
 /**
@@ -39,7 +41,8 @@ private[spark] object FixedLengthBinaryInputFormat {
 }
 
 private[spark] class FixedLengthBinaryInputFormat
-  extends FileInputFormat[LongWritable, BytesWritable] {
+  extends FileInputFormat[LongWritable, BytesWritable]
+  with Logging {
 
   private var recordLength = -1
 
@@ -51,7 +54,7 @@ private[spark] class FixedLengthBinaryInputFormat
       recordLength = FixedLengthBinaryInputFormat.getRecordLength(context)
     }
     if (recordLength <= 0) {
-      println("record length is less than 0, file cannot be split")
+      logDebug("record length is less than 0, file cannot be split")
       false
     } else {
       true
diff --git a/core/src/main/scala/org/apache/spark/network/nio/BlockMessage.scala b/core/src/main/scala/org/apache/spark/network/nio/BlockMessage.scala
index 67a3761029..79cb0640c8 100644
--- a/core/src/main/scala/org/apache/spark/network/nio/BlockMessage.scala
+++ b/core/src/main/scala/org/apache/spark/network/nio/BlockMessage.scala
@@ -57,16 +57,6 @@ private[nio] class BlockMessage() {
   }
 
   def set(buffer: ByteBuffer) {
-    /*
-    println()
-    println("BlockMessage: ")
-    while(buffer.remaining > 0) {
-      print(buffer.get())
-    }
-    buffer.rewind()
-    println()
-    println()
-    */
     typ = buffer.getInt()
     val idLength = buffer.getInt()
     val idBuilder = new StringBuilder(idLength)
@@ -138,18 +128,6 @@ private[nio] class BlockMessage() {
       buffers += data
     }
 
-    /*
-    println()
-    println("BlockMessage: ")
-    buffers.foreach(b => {
-      while(b.remaining > 0) {
-        print(b.get())
-      }
-      b.rewind()
-    })
-    println()
-    println()
-    */
     Message.createBufferMessage(buffers)
   }
 
diff --git a/core/src/main/scala/org/apache/spark/network/nio/BlockMessageArray.scala b/core/src/main/scala/org/apache/spark/network/nio/BlockMessageArray.scala
index 7d0806f0c2..f1c9ea8b64 100644
--- a/core/src/main/scala/org/apache/spark/network/nio/BlockMessageArray.scala
+++ b/core/src/main/scala/org/apache/spark/network/nio/BlockMessageArray.scala
@@ -43,16 +43,6 @@ class BlockMessageArray(var blockMessages: Seq[BlockMessage])
     val newBlockMessages = new ArrayBuffer[BlockMessage]()
     val buffer = bufferMessage.buffers(0)
     buffer.clear()
-    /*
-    println()
-    println("BlockMessageArray: ")
-    while(buffer.remaining > 0) {
-      print(buffer.get())
-    }
-    buffer.rewind()
-    println()
-    println()
-    */
     while (buffer.remaining() > 0) {
       val size = buffer.getInt()
       logDebug("Creating block message of size " + size + " bytes")
@@ -86,23 +76,11 @@ class BlockMessageArray(var blockMessages: Seq[BlockMessage])
 
     logDebug("Buffer list:")
     buffers.foreach((x: ByteBuffer) => logDebug("" + x))
-    /*
-    println()
-    println("BlockMessageArray: ")
-    buffers.foreach(b => {
-      while(b.remaining > 0) {
-        print(b.get())
-      }
-      b.rewind()
-    })
-    println()
-    println()
-    */
     Message.createBufferMessage(buffers)
   }
 }
 
-private[nio] object BlockMessageArray {
+private[nio] object BlockMessageArray extends Logging {
 
   def fromBufferMessage(bufferMessage: BufferMessage): BlockMessageArray = {
     val newBlockMessageArray = new BlockMessageArray()
@@ -123,10 +101,10 @@ private[nio] object BlockMessageArray {
         }
       }
     val blockMessageArray = new BlockMessageArray(blockMessages)
-    println("Block message array created")
+    logDebug("Block message array created")
 
     val bufferMessage = blockMessageArray.toBufferMessage
-    println("Converted to buffer message")
+    logDebug("Converted to buffer message")
 
     val totalSize = bufferMessage.size
     val newBuffer = ByteBuffer.allocate(totalSize)
@@ -138,10 +116,11 @@ private[nio] object BlockMessageArray {
     })
     newBuffer.flip
     val newBufferMessage = Message.createBufferMessage(newBuffer)
-    println("Copied to new buffer message, size = " + newBufferMessage.size)
+    logDebug("Copied to new buffer message, size = " + newBufferMessage.size)
 
     val newBlockMessageArray = BlockMessageArray.fromBufferMessage(newBufferMessage)
-    println("Converted back to block message array")
+    logDebug("Converted back to block message array")
+    // scalastyle:off println
     newBlockMessageArray.foreach(blockMessage => {
       blockMessage.getType match {
         case BlockMessage.TYPE_PUT_BLOCK => {
@@ -154,6 +133,7 @@ private[nio] object BlockMessageArray {
         }
       }
     })
+    // scalastyle:on println
   }
 }
 
diff --git a/core/src/main/scala/org/apache/spark/network/nio/ConnectionManager.scala b/core/src/main/scala/org/apache/spark/network/nio/ConnectionManager.scala
index c0bca2c4bc..9143918790 100644
--- a/core/src/main/scala/org/apache/spark/network/nio/ConnectionManager.scala
+++ b/core/src/main/scala/org/apache/spark/network/nio/ConnectionManager.scala
@@ -1016,7 +1016,9 @@ private[spark] object ConnectionManager {
     val conf = new SparkConf
     val manager = new ConnectionManager(9999, conf, new SecurityManager(conf))
     manager.onReceiveMessage((msg: Message, id: ConnectionManagerId) => {
+      // scalastyle:off println
       println("Received [" + msg + "] from [" + id + "]")
+      // scalastyle:on println
       None
     })
 
@@ -1033,6 +1035,7 @@ private[spark] object ConnectionManager {
     System.gc()
   }
 
+  // scalastyle:off println
   def testSequentialSending(manager: ConnectionManager) {
     println("--------------------------")
     println("Sequential Sending")
@@ -1150,4 +1153,5 @@ private[spark] object ConnectionManager {
       println()
     }
   }
+  // scalastyle:on println
 }
diff --git a/core/src/main/scala/org/apache/spark/rdd/PipedRDD.scala b/core/src/main/scala/org/apache/spark/rdd/PipedRDD.scala
index dc60d48927..defdabf95a 100644
--- a/core/src/main/scala/org/apache/spark/rdd/PipedRDD.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/PipedRDD.scala
@@ -123,7 +123,9 @@ private[spark] class PipedRDD[T: ClassTag](
     new Thread("stderr reader for " + command) {
       override def run() {
         for (line <- Source.fromInputStream(proc.getErrorStream).getLines) {
+          // scalastyle:off println
           System.err.println(line)
+          // scalastyle:on println
         }
       }
     }.start()
@@ -133,6 +135,7 @@ private[spark] class PipedRDD[T: ClassTag](
       override def run() {
         val out = new PrintWriter(proc.getOutputStream)
 
+        // scalastyle:off println
         // input the pipe context firstly
         if (printPipeContext != null) {
           printPipeContext(out.println(_))
@@ -144,6 +147,7 @@ private[spark] class PipedRDD[T: ClassTag](
             out.println(elem)
           }
         }
+        // scalastyle:on println
         out.close()
       }
     }.start()
diff --git a/core/src/main/scala/org/apache/spark/scheduler/EventLoggingListener.scala b/core/src/main/scala/org/apache/spark/scheduler/EventLoggingListener.scala
index 529a5b2bf1..62b05033a9 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/EventLoggingListener.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/EventLoggingListener.scala
@@ -140,7 +140,9 @@ private[spark] class EventLoggingListener(
   /** Log the event as JSON. */
   private def logEvent(event: SparkListenerEvent, flushLogger: Boolean = false) {
     val eventJson = JsonProtocol.sparkEventToJson(event)
+    // scalastyle:off println
     writer.foreach(_.println(compact(render(eventJson))))
+    // scalastyle:on println
     if (flushLogger) {
       writer.foreach(_.flush())
       hadoopDataStream.foreach(hadoopFlushMethod.invoke(_))
diff --git a/core/src/main/scala/org/apache/spark/scheduler/JobLogger.scala b/core/src/main/scala/org/apache/spark/scheduler/JobLogger.scala
index e55b76c36c..f96eb8ca0a 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/JobLogger.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/JobLogger.scala
@@ -125,7 +125,9 @@ class JobLogger(val user: String, val logDirName: String) extends SparkListener
       val date = new Date(System.currentTimeMillis())
       writeInfo = dateFormat.get.format(date) + ": " + info
     }
+    // scalastyle:off println
     jobIdToPrintWriter.get(jobId).foreach(_.println(writeInfo))
+    // scalastyle:on println
   }
 
   /**
diff --git a/core/src/main/scala/org/apache/spark/ui/JettyUtils.scala b/core/src/main/scala/org/apache/spark/ui/JettyUtils.scala
index f413c1d37f..c8356467fa 100644
--- a/core/src/main/scala/org/apache/spark/ui/JettyUtils.scala
+++ b/core/src/main/scala/org/apache/spark/ui/JettyUtils.scala
@@ -68,7 +68,9 @@ private[spark] object JettyUtils extends Logging {
             response.setStatus(HttpServletResponse.SC_OK)
             val result = servletParams.responder(request)
             response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate")
+            // scalastyle:off println
             response.getWriter.println(servletParams.extractFn(result))
+            // scalastyle:on println
           } else {
             response.setStatus(HttpServletResponse.SC_UNAUTHORIZED)
             response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate")
diff --git a/core/src/main/scala/org/apache/spark/ui/UIWorkloadGenerator.scala b/core/src/main/scala/org/apache/spark/ui/UIWorkloadGenerator.scala
index ba03acdb38..5a8c291431 100644
--- a/core/src/main/scala/org/apache/spark/ui/UIWorkloadGenerator.scala
+++ b/core/src/main/scala/org/apache/spark/ui/UIWorkloadGenerator.scala
@@ -38,9 +38,11 @@ private[spark] object UIWorkloadGenerator {
 
   def main(args: Array[String]) {
     if (args.length < 3) {
+      // scalastyle:off println
       println(
-        "usage: ./bin/spark-class org.apache.spark.ui.UIWorkloadGenerator " +
+        "Usage: ./bin/spark-class org.apache.spark.ui.UIWorkloadGenerator " +
           "[master] [FIFO|FAIR] [#job set (4 jobs per set)]")
+      // scalastyle:on println
       System.exit(1)
     }
 
@@ -96,6 +98,7 @@ private[spark] object UIWorkloadGenerator {
       for ((desc, job) <- jobs) {
         new Thread {
           override def run() {
+            // scalastyle:off println
             try {
               setProperties(desc)
               job()
@@ -106,6 +109,7 @@ private[spark] object UIWorkloadGenerator {
             } finally {
               barrier.release()
             }
+            // scalastyle:on println
           }
         }.start
         Thread.sleep(INTER_JOB_WAIT_MS)
diff --git a/core/src/main/scala/org/apache/spark/util/Distribution.scala b/core/src/main/scala/org/apache/spark/util/Distribution.scala
index 1bab707235..950b69f7db 100644
--- a/core/src/main/scala/org/apache/spark/util/Distribution.scala
+++ b/core/src/main/scala/org/apache/spark/util/Distribution.scala
@@ -52,9 +52,11 @@ private[spark] class Distribution(val data: Array[Double], val startIdx: Int, va
   }
 
   def showQuantiles(out: PrintStream = System.out): Unit = {
+    // scalastyle:off println
     out.println("min\t25%\t50%\t75%\tmax")
     getQuantiles(defaultProbabilities).foreach{q => out.print(q + "\t")}
     out.println
+    // scalastyle:on println
   }
 
   def statCounter: StatCounter = StatCounter(data.slice(startIdx, endIdx))
@@ -64,8 +66,10 @@ private[spark] class Distribution(val data: Array[Double], val startIdx: Int, va
    * @param out
    */
   def summary(out: PrintStream = System.out) {
+    // scalastyle:off println
     out.println(statCounter)
     showQuantiles(out)
+    // scalastyle:on println
   }
 }
 
@@ -80,8 +84,10 @@ private[spark] object Distribution {
   }
 
   def showQuantiles(out: PrintStream = System.out, quantiles: Traversable[Double]) {
+    // scalastyle:off println
     out.println("min\t25%\t50%\t75%\tmax")
     quantiles.foreach{q => out.print(q + "\t")}
     out.println
+    // scalastyle:on println
   }
 }
diff --git a/core/src/main/scala/org/apache/spark/util/random/XORShiftRandom.scala b/core/src/main/scala/org/apache/spark/util/random/XORShiftRandom.scala
index c4a7b4441c..85fb923cd9 100644
--- a/core/src/main/scala/org/apache/spark/util/random/XORShiftRandom.scala
+++ b/core/src/main/scala/org/apache/spark/util/random/XORShiftRandom.scala
@@ -70,12 +70,14 @@ private[spark] object XORShiftRandom {
    * @param args takes one argument - the number of random numbers to generate
    */
   def main(args: Array[String]): Unit = {
+    // scalastyle:off println
     if (args.length != 1) {
       println("Benchmark of XORShiftRandom vis-a-vis java.util.Random")
       println("Usage: XORShiftRandom number_of_random_numbers_to_generate")
       System.exit(1)
     }
     println(benchmark(args(0).toInt))
+    // scalastyle:on println
   }
 
   /**
diff --git a/core/src/test/scala/org/apache/spark/DistributedSuite.scala b/core/src/test/scala/org/apache/spark/DistributedSuite.scala
index 9c191ed522..2300bcff4f 100644
--- a/core/src/test/scala/org/apache/spark/DistributedSuite.scala
+++ b/core/src/test/scala/org/apache/spark/DistributedSuite.scala
@@ -107,7 +107,9 @@ class DistributedSuite extends SparkFunSuite with Matchers with LocalSparkContex
     sc = new SparkContext(clusterUrl, "test")
     val accum = sc.accumulator(0)
     val thrown = intercept[SparkException] {
+      // scalastyle:off println
       sc.parallelize(1 to 10, 10).foreach(x => println(x / 0))
+      // scalastyle:on println
     }
     assert(thrown.getClass === classOf[SparkException])
     assert(thrown.getMessage.contains("failed 4 times"))
diff --git a/core/src/test/scala/org/apache/spark/FailureSuite.scala b/core/src/test/scala/org/apache/spark/FailureSuite.scala
index a8c8c6f73f..b099cd3fb7 100644
--- a/core/src/test/scala/org/apache/spark/FailureSuite.scala
+++ b/core/src/test/scala/org/apache/spark/FailureSuite.scala
@@ -130,7 +130,9 @@ class FailureSuite extends SparkFunSuite with LocalSparkContext {
 
     // Non-serializable closure in foreach function
     val thrown2 = intercept[SparkException] {
+      // scalastyle:off println
       sc.parallelize(1 to 10, 2).foreach(x => println(a))
+      // scalastyle:on println
     }
     assert(thrown2.getClass === classOf[SparkException])
     assert(thrown2.getMessage.contains("NotSerializableException") ||
diff --git a/core/src/test/scala/org/apache/spark/FileServerSuite.scala b/core/src/test/scala/org/apache/spark/FileServerSuite.scala
index 6e65b0a8f6..876418aa13 100644
--- a/core/src/test/scala/org/apache/spark/FileServerSuite.scala
+++ b/core/src/test/scala/org/apache/spark/FileServerSuite.scala
@@ -51,7 +51,9 @@ class FileServerSuite extends SparkFunSuite with LocalSparkContext {
 
     val textFile = new File(testTempDir, "FileServerSuite.txt")
     val pw = new PrintWriter(textFile)
+    // scalastyle:off println
     pw.println("100")
+    // scalastyle:on println
     pw.close()
 
     val jarFile = new File(testTempDir, "test.jar")
diff --git a/core/src/test/scala/org/apache/spark/ThreadingSuite.scala b/core/src/test/scala/org/apache/spark/ThreadingSuite.scala
index 6580139df6..48509f0759 100644
--- a/core/src/test/scala/org/apache/spark/ThreadingSuite.scala
+++ b/core/src/test/scala/org/apache/spark/ThreadingSuite.scala
@@ -36,7 +36,7 @@ object ThreadingSuiteState {
   }
 }
 
-class ThreadingSuite extends SparkFunSuite with LocalSparkContext {
+class ThreadingSuite extends SparkFunSuite with LocalSparkContext with Logging {
 
   test("accessing SparkContext form a different thread") {
     sc = new SparkContext("local", "test")
@@ -130,8 +130,6 @@ class ThreadingSuite extends SparkFunSuite with LocalSparkContext {
               Thread.sleep(100)
             }
             if (running.get() != 4) {
-              println("Waited 1 second without seeing runningThreads = 4 (it was " +
-                running.get() + "); failing test")
               ThreadingSuiteState.failed.set(true)
             }
             number
@@ -143,6 +141,8 @@ class ThreadingSuite extends SparkFunSuite with LocalSparkContext {
     }
     sem.acquire(2)
     if (ThreadingSuiteState.failed.get()) {
+      logError("Waited 1 second without seeing runningThreads = 4 (it was " +
+                ThreadingSuiteState.runningThreads.get() + "); failing test")
       fail("One or more threads didn't see runningThreads = 4")
     }
   }
diff --git a/core/src/test/scala/org/apache/spark/deploy/SparkSubmitSuite.scala b/core/src/test/scala/org/apache/spark/deploy/SparkSubmitSuite.scala
index 2e05dec99b..1b64c329b5 100644
--- a/core/src/test/scala/org/apache/spark/deploy/SparkSubmitSuite.scala
+++ b/core/src/test/scala/org/apache/spark/deploy/SparkSubmitSuite.scala
@@ -51,9 +51,11 @@ class SparkSubmitSuite
   /** Simple PrintStream that reads data into a buffer */
   private class BufferPrintStream extends PrintStream(noOpOutputStream) {
     var lineBuffer = ArrayBuffer[String]()
+    // scalastyle:off println
     override def println(line: String) {
       lineBuffer += line
     }
+    // scalastyle:on println
   }
 
   /** Returns true if the script exits and the given search string is printed. */
@@ -81,6 +83,7 @@ class SparkSubmitSuite
     }
   }
 
+  // scalastyle:off println
   test("prints usage on empty input") {
     testPrematureExit(Array[String](), "Usage: spark-submit")
   }
@@ -491,6 +494,7 @@ class SparkSubmitSuite
       appArgs.executorMemory should be ("2.3g")
     }
   }
+  // scalastyle:on println
 
   // NOTE: This is an expensive operation in terms of time (10 seconds+). Use sparingly.
   private def runSparkSubmit(args: Seq[String]): Unit = {
diff --git a/core/src/test/scala/org/apache/spark/deploy/SparkSubmitUtilsSuite.scala b/core/src/test/scala/org/apache/spark/deploy/SparkSubmitUtilsSuite.scala
index c9b435a922..01ece1a10f 100644
--- a/core/src/test/scala/org/apache/spark/deploy/SparkSubmitUtilsSuite.scala
+++ b/core/src/test/scala/org/apache/spark/deploy/SparkSubmitUtilsSuite.scala
@@ -41,9 +41,11 @@ class SparkSubmitUtilsSuite extends SparkFunSuite with BeforeAndAfterAll {
   /** Simple PrintStream that reads data into a buffer */
   private class BufferPrintStream extends PrintStream(noOpOutputStream) {
     var lineBuffer = ArrayBuffer[String]()
+    // scalastyle:off println
     override def println(line: String) {
       lineBuffer += line
     }
+    // scalastyle:on println
   }
 
   override def beforeAll() {
diff --git a/core/src/test/scala/org/apache/spark/input/WholeTextFileRecordReaderSuite.scala b/core/src/test/scala/org/apache/spark/input/WholeTextFileRecordReaderSuite.scala
index 63947df3d4..8a199459c1 100644
--- a/core/src/test/scala/org/apache/spark/input/WholeTextFileRecordReaderSuite.scala
+++ b/core/src/test/scala/org/apache/spark/input/WholeTextFileRecordReaderSuite.scala
@@ -27,7 +27,7 @@ import org.scalatest.BeforeAndAfterAll
 
 import org.apache.hadoop.io.Text
 
-import org.apache.spark.{SparkConf, SparkContext, SparkFunSuite}
+import org.apache.spark.{Logging, SparkConf, SparkContext, SparkFunSuite}
 import org.apache.spark.util.Utils
 import org.apache.hadoop.io.compress.{DefaultCodec, CompressionCodecFactory, GzipCodec}
 
@@ -36,7 +36,7 @@ import org.apache.hadoop.io.compress.{DefaultCodec, CompressionCodecFactory, Gzi
  * [[org.apache.spark.input.WholeTextFileRecordReader WholeTextFileRecordReader]]. A temporary
  * directory is created as fake input. Temporal storage would be deleted in the end.
  */
-class WholeTextFileRecordReaderSuite extends SparkFunSuite with BeforeAndAfterAll {
+class WholeTextFileRecordReaderSuite extends SparkFunSuite with BeforeAndAfterAll with Logging {
   private var sc: SparkContext = _
   private var factory: CompressionCodecFactory = _
 
@@ -85,7 +85,7 @@ class WholeTextFileRecordReaderSuite extends SparkFunSuite with BeforeAndAfterAl
    */
   test("Correctness of WholeTextFileRecordReader.") {
     val dir = Utils.createTempDir()
-    println(s"Local disk address is ${dir.toString}.")
+    logInfo(s"Local disk address is ${dir.toString}.")
 
     WholeTextFileRecordReaderSuite.files.foreach { case (filename, contents) =>
       createNativeFile(dir, filename, contents, false)
@@ -109,7 +109,7 @@ class WholeTextFileRecordReaderSuite extends SparkFunSuite with BeforeAndAfterAl
 
   test("Correctness of WholeTextFileRecordReader with GzipCodec.") {
     val dir = Utils.createTempDir()
-    println(s"Local disk address is ${dir.toString}.")
+    logInfo(s"Local disk address is ${dir.toString}.")
 
     WholeTextFileRecordReaderSuite.files.foreach { case (filename, contents) =>
       createNativeFile(dir, filename, contents, true)
diff --git a/core/src/test/scala/org/apache/spark/metrics/InputOutputMetricsSuite.scala b/core/src/test/scala/org/apache/spark/metrics/InputOutputMetricsSuite.scala
index 9e4d34fb7d..d3218a548e 100644
--- a/core/src/test/scala/org/apache/spark/metrics/InputOutputMetricsSuite.scala
+++ b/core/src/test/scala/org/apache/spark/metrics/InputOutputMetricsSuite.scala
@@ -60,7 +60,9 @@ class InputOutputMetricsSuite extends SparkFunSuite with SharedSparkContext
     tmpFile = new File(testTempDir, getClass.getSimpleName + ".txt")
     val pw = new PrintWriter(new FileWriter(tmpFile))
     for (x <- 1 to numRecords) {
+      // scalastyle:off println
       pw.println(RandomUtils.nextInt(0, numBuckets))
+      // scalastyle:on println
     }
     pw.close()
 
diff --git a/core/src/test/scala/org/apache/spark/scheduler/ReplayListenerSuite.scala b/core/src/test/scala/org/apache/spark/scheduler/ReplayListenerSuite.scala
index ff3fa95ec3..4e3defb43a 100644
--- a/core/src/test/scala/org/apache/spark/scheduler/ReplayListenerSuite.scala
+++ b/core/src/test/scala/org/apache/spark/scheduler/ReplayListenerSuite.scala
@@ -52,8 +52,10 @@ class ReplayListenerSuite extends SparkFunSuite with BeforeAndAfter {
     val applicationStart = SparkListenerApplicationStart("Greatest App (N)ever", None,
       125L, "Mickey", None)
     val applicationEnd = SparkListenerApplicationEnd(1000L)
+    // scalastyle:off println
     writer.println(compact(render(JsonProtocol.sparkEventToJson(applicationStart))))
     writer.println(compact(render(JsonProtocol.sparkEventToJson(applicationEnd))))
+    // scalastyle:on println
     writer.close()
 
     val conf = EventLoggingListenerSuite.getLoggingConf(logFilePath)
diff --git a/core/src/test/scala/org/apache/spark/util/ClosureCleanerSuite.scala b/core/src/test/scala/org/apache/spark/util/ClosureCleanerSuite.scala
index 1053c6caf7..480722a5ac 100644
--- a/core/src/test/scala/org/apache/spark/util/ClosureCleanerSuite.scala
+++ b/core/src/test/scala/org/apache/spark/util/ClosureCleanerSuite.scala
@@ -375,6 +375,7 @@ class TestCreateNullValue {
     // parameters of the closure constructor. This allows us to test whether
     // null values are created correctly for each type.
     val nestedClosure = () => {
+      // scalastyle:off println
       if (s.toString == "123") { // Don't really output them to avoid noisy
         println(bo)
         println(c)
@@ -389,6 +390,7 @@ class TestCreateNullValue {
       val closure = () => {
         println(getX)
       }
+      // scalastyle:on println
       ClosureCleaner.clean(closure)
     }
     nestedClosure()
diff --git a/core/src/test/scala/org/apache/spark/util/UtilsSuite.scala b/core/src/test/scala/org/apache/spark/util/UtilsSuite.scala
index 251a797dc2..c7638507c8 100644
--- a/core/src/test/scala/org/apache/spark/util/UtilsSuite.scala
+++ b/core/src/test/scala/org/apache/spark/util/UtilsSuite.scala
@@ -684,7 +684,9 @@ class UtilsSuite extends SparkFunSuite with ResetSystemProperties with Logging {
     val buffer = new CircularBuffer(25)
     val stream = new java.io.PrintStream(buffer, true, "UTF-8")
 
+    // scalastyle:off println
     stream.println("test circular test circular test circular test circular test circular")
+    // scalastyle:on println
     assert(buffer.toString === "t circular test circular\n")
   }
 }
diff --git a/core/src/test/scala/org/apache/spark/util/collection/SizeTrackerSuite.scala b/core/src/test/scala/org/apache/spark/util/collection/SizeTrackerSuite.scala
index 5a5919fca2..4f382414a8 100644
--- a/core/src/test/scala/org/apache/spark/util/collection/SizeTrackerSuite.scala
+++ b/core/src/test/scala/org/apache/spark/util/collection/SizeTrackerSuite.scala
@@ -103,7 +103,9 @@ private object SizeTrackerSuite {
    */
   def main(args: Array[String]): Unit = {
     if (args.size < 1) {
+      // scalastyle:off println
       println("Usage: SizeTrackerSuite [num elements]")
+      // scalastyle:on println
       System.exit(1)
     }
     val numElements = args(0).toInt
@@ -180,11 +182,13 @@ private object SizeTrackerSuite {
       baseTimes: Seq[Long],
       sampledTimes: Seq[Long],
       unsampledTimes: Seq[Long]): Unit = {
+    // scalastyle:off println
     println(s"Average times for $testName (ms):")
     println("  Base - " + averageTime(baseTimes))
     println("  SizeTracker (sampled) - " + averageTime(sampledTimes))
     println("  SizeEstimator (unsampled) - " + averageTime(unsampledTimes))
     println()
+    // scalastyle:on println
   }
 
   def time(f: => Unit): Long = {
diff --git a/core/src/test/scala/org/apache/spark/util/collection/SorterSuite.scala b/core/src/test/scala/org/apache/spark/util/collection/SorterSuite.scala
index b2f5d9009e..fefa5165db 100644
--- a/core/src/test/scala/org/apache/spark/util/collection/SorterSuite.scala
+++ b/core/src/test/scala/org/apache/spark/util/collection/SorterSuite.scala
@@ -20,10 +20,10 @@ package org.apache.spark.util.collection
 import java.lang.{Float => JFloat, Integer => JInteger}
 import java.util.{Arrays, Comparator}
 
-import org.apache.spark.SparkFunSuite
+import org.apache.spark.{Logging, SparkFunSuite}
 import org.apache.spark.util.random.XORShiftRandom
 
-class SorterSuite extends SparkFunSuite {
+class SorterSuite extends SparkFunSuite with Logging {
 
   test("equivalent to Arrays.sort") {
     val rand = new XORShiftRandom(123)
@@ -74,7 +74,7 @@ class SorterSuite extends SparkFunSuite {
   /** Runs an experiment several times. */
   def runExperiment(name: String, skip: Boolean = false)(f: => Unit, prepare: () => Unit): Unit = {
     if (skip) {
-      println(s"Skipped experiment $name.")
+      logInfo(s"Skipped experiment $name.")
       return
     }
 
@@ -86,11 +86,11 @@ class SorterSuite extends SparkFunSuite {
     while (i < 10) {
       val time = org.apache.spark.util.Utils.timeIt(1)(f, Some(prepare))
       next10 += time
-      println(s"$name: Took $time ms")
+      logInfo(s"$name: Took $time ms")
       i += 1
     }
 
-    println(s"$name: ($firstTry ms first try, ${next10 / 10} ms average)")
+    logInfo(s"$name: ($firstTry ms first try, ${next10 / 10} ms average)")
   }
 
   /**