[SPARK-16952] don't lookup spark home directory when executor uri is set

## What changes were proposed in this pull request?

remove requirement to set spark.mesos.executor.home when spark.executor.uri is used

## How was this patch tested?

unit tests

Author: Michael Gummelt <mgummelt@mesosphere.io>

Closes #14552 from mgummelt/fix-spark-home.

1 files changed, 5 insertions, 5 deletions

diff --git a/core/src/main/scala/org/apache/spark/scheduler/cluster/mesos/MesosCoarseGrainedSchedulerBackend.scala b/core/src/main/scala/org/apache/spark/scheduler/cluster/mesos/MesosCoarseGrainedSchedulerBackend.scala
index 0933a03a0f..4a88824854 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/cluster/mesos/MesosCoarseGrainedSchedulerBackend.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/cluster/mesos/MesosCoarseGrainedSchedulerBackend.scala
@@ -163,11 +163,6 @@ private[spark] class MesosCoarseGrainedSchedulerBackend(
   }
 
   def createCommand(offer: Offer, numCores: Int, taskId: String): CommandInfo = {
-    val executorSparkHome = conf.getOption("spark.mesos.executor.home")
-      .orElse(sc.getSparkHome())
-      .getOrElse {
-        throw new SparkException("Executor Spark home `spark.mesos.executor.home` is not set!")
-      }
     val environment = Environment.newBuilder()
     val extraClassPath = conf.getOption("spark.executor.extraClassPath")
     extraClassPath.foreach { cp =>
@@ -201,6 +196,11 @@ private[spark] class MesosCoarseGrainedSchedulerBackend(
       .orElse(Option(System.getenv("SPARK_EXECUTOR_URI")))
 
     if (uri.isEmpty) {
+      val executorSparkHome = conf.getOption("spark.mesos.executor.home")
+        .orElse(sc.getSparkHome())
+        .getOrElse {
+          throw new SparkException("Executor Spark home `spark.mesos.executor.home` is not set!")
+        }
       val runScript = new File(executorSparkHome, "./bin/spark-class").getPath
       command.setValue(
         "%s \"%s\" org.apache.spark.executor.CoarseGrainedExecutorBackend"