[SPARK-10986][MESOS] Set the context class loader in the Mesos execut…

…or backend. See [SPARK-10986](https://issues.apache.org/jira/browse/SPARK-10986) for details. This fixes the `ClassNotFoundException` for Spark classes in the serializer. I am not sure this is the right way to handle the class loader, but I couldn't find any documentation on how the context class loader is used and who relies on it. It seems at least the serializer uses it to instantiate classes during deserialization. I am open to suggestions (I tried this fix on a real Mesos cluster and it *does* fix the issue). tnachen andrewor14 Author: Iulian Dragos <[email protected]> Closes apache#9282 from dragos/issue/mesos-classloader.
mrares · Oct 30, 2015 · 0451b00 · 0451b00
1 parent 14d08b9
commit 0451b00
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/core/src/main/scala/org/apache/spark/executor/MesosExecutorBackend.scala b/core/src/main/scala/org/apache/spark/executor/MesosExecutorBackend.scala
@@ -63,6 +63,11 @@ private[spark] class MesosExecutorBackend
 
     logInfo(s"Registered with Mesos as executor ID $executorId with $cpusPerTask cpus")
     this.driver = driver
+    // Set a context class loader to be picked up by the serializer. Without this call
+    // the serializer would default to the null class loader, and fail to find Spark classes
+    // See SPARK-10986.
+    Thread.currentThread().setContextClassLoader(this.getClass.getClassLoader)
+
     val properties = Utils.deserialize[Array[(String, String)]](executorInfo.getData.toByteArray) ++
       Seq[(String, String)](("spark.app.id", frameworkInfo.getId.getValue))
     val conf = new SparkConf(loadDefaults = true).setAll(properties)