CR feedback. Hide the log column if there are no logs available

Author: Kostas Sakellis

core/src/main/scala/org/apache/spark/executor/CoarseGrainedExecutorBackend.scala

@@ -53,7 +53,7 @@ private[spark] class CoarseGrainedExecutorBackend(
     context.system.eventStream.subscribe(self, classOf[RemotingLifecycleEvent])
   }
 
-  def extractLogUrls : Map[String, String] = {
+  def extractLogUrls: Map[String, String] = {
     val prefix = "SPARK_LOG_URL_"
     sys.env.filterKeys(_.startsWith(prefix))
       .map(e => (e._1.substring(prefix.length).toLowerCase, e._2))

core/src/main/scala/org/apache/spark/ui/exec/ExecutorsPage.scala

@@ -56,6 +56,7 @@ private[ui] class ExecutorsPage(
     val diskUsed = storageStatusList.map(_.diskUsed).sum
     val execInfo = for (statusId <- 0 until storageStatusList.size) yield getExecInfo(statusId)
     val execInfoSorted = execInfo.sortBy(_.id)
+    val logsExist = execInfo.filter(_.executorLogs.nonEmpty).nonEmpty
 
     val execTable =
       <table class={UIUtils.TABLE_CLASS_STRIPED}>
@@ -80,11 +81,11 @@ private[ui] class ExecutorsPage(
               Shuffle Write
             </span>
           </th>
-          <th class="sorttable_nosort">Logs</th>
+          {if (logsExist) <th class="sorttable_nosort">Logs</th> else Seq.empty}
           {if (threadDumpEnabled) <th class="sorttable_nosort">Thread Dump</th> else Seq.empty}
         </thead>
         <tbody>
-          {execInfoSorted.map(execRow)}
+          {execInfoSorted.map(execRow(_, logsExist))}
         </tbody>
       </table>
 
@@ -109,7 +110,7 @@ private[ui] class ExecutorsPage(
   }
 
   /** Render an HTML row representing an executor */
-  private def execRow(info: ExecutorSummaryInfo): Seq[Node] = {
+  private def execRow(info: ExecutorSummaryInfo, logsExist: Boolean): Seq[Node] = {
     val maximumMemory = info.maxMemory
     val memoryUsed = info.memoryUsed
     val diskUsed = info.diskUsed
@@ -140,13 +141,19 @@ private[ui] class ExecutorsPage(
       <td sorttable_customkey={info.totalShuffleWrite.toString}>
         {Utils.bytesToString(info.totalShuffleWrite)}
       </td>
-      <td>
       {
-        info.executorLogs.map(entry => {
-          <div><a href={s"${entry._2}"}>{entry._1}</a></div>
-        })
+        if (logsExist) {
+          <td>
+            {info.executorLogs.map { entry => {
+            <div>
+              <a href={s"${entry._2}"}>
+                {entry._1}
+              </a>
+            </div>}
+            }}
+          </td>
+        }
       }
-      </td>
       {
         if (threadDumpEnabled) {
           val encodedId = URLEncoder.encode(info.id, "UTF-8")

yarn/src/test/scala/org/apache/spark/deploy/yarn/YarnClusterSuite.scala

@@ -20,22 +20,19 @@ package org.apache.spark.deploy.yarn
 import java.io.File
 import java.util.concurrent.TimeUnit
 
-import org.apache.spark.scheduler.cluster.ExecutorInfo
-import org.apache.spark.scheduler.{SparkListener, SparkListenerExecutorAdded}
-
 import scala.collection.JavaConversions._
+import scala.collection.mutable
 
 import com.google.common.base.Charsets
 import com.google.common.io.Files
-import org.scalatest.{BeforeAndAfterAll, FunSuite, Matchers}
-
 import org.apache.hadoop.yarn.conf.YarnConfiguration
 import org.apache.hadoop.yarn.server.MiniYARNCluster
+import org.scalatest.{BeforeAndAfterAll, FunSuite, Matchers}
 
-import org.apache.spark.{Logging, SparkConf, SparkContext, SparkException}
+import org.apache.spark.scheduler.cluster.ExecutorInfo
+import org.apache.spark.scheduler.{SparkListener, SparkListenerExecutorAdded}
 import org.apache.spark.util.Utils
-
-import scala.collection.mutable
+import org.apache.spark.{Logging, SparkConf, SparkContext, SparkException}
 
 class YarnClusterSuite extends FunSuite with BeforeAndAfterAll with Matchers with Logging {
 
@@ -167,9 +164,9 @@ class YarnClusterSuite extends FunSuite with BeforeAndAfterAll with Matchers wit
     checkResult(result)
 
     // verify log urls are present.
-    YarnClusterDriver.listener.addedExecutorInfos.foreach(e => {
+    YarnClusterDriver.listener.addedExecutorInfos.foreach { e => {
       assert(e._2.logUrlMap.nonEmpty)
-    })
+    }}
   }
 
   test("run Spark in yarn-cluster mode unsuccessfully") {