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Marco Zanghì commented on SPARK-9339: ------------------------------------- I have a problem using Utils.classForName() . it returns always nullpointException. Any Ideas? > Use of Class.forName(String) should be replaced with version taking > classloader > ------------------------------------------------------------------------------- > > Key: SPARK-9339 > URL: https://issues.apache.org/jira/browse/SPARK-9339 > Project: Spark > Issue Type: Bug > Affects Versions: 1.3.1 > Reporter: Mridul Muralidharan > Attachments: screenshot-1yarn-cluster error.png > > > In spark, multiple places have ability to take external class as input - > example: listener. > Other than in specific cases (like SparkEnv), the code typically calls > Class.forName(clazzName) > This works when the class is from within spark - but when the referenced > class is from external jar (user provided), it tends to fail. > For example, in 1.3 we get this when using custom listener: > ERROR ApplicationMaster: User class threw exception: Exception when > registering SparkListener > org.apache.spark.SparkException: Exception when registering SparkListener > at > org.apache.spark.SparkContext.setupAndStartListenerBus(SparkContext.scala:1726) > at org.apache.spark.SparkContext.<init>(SparkContext.scala:429) > at org.apache.spark.SparkContext.<init>(SparkContext.scala:134) > at > com.yahoo.corp.yst.webmap.spark.PageRankDataGenerator$.main(PageRankDataGenerator.scala:170) > at > com.yahoo.corp.yst.webmap.spark.PageRankDataGenerator.main(PageRankDataGenerator.scala) > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) > at > sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) > at java.lang.reflect.Method.invoke(Method.java:606) > at > org.apache.spark.deploy.yarn.ApplicationMaster$$anon$2.run(ApplicationMaster.scala:480) > Caused by: java.lang.ClassNotFoundException: <MySparkListener> > at java.net.URLClassLoader$1.run(URLClassLoader.java:366) > at java.net.URLClassLoader$1.run(URLClassLoader.java:355) > at java.security.AccessController.doPrivileged(Native Method) > at java.net.URLClassLoader.findClass(URLClassLoader.java:354) > at java.lang.ClassLoader.loadClass(ClassLoader.java:425) > at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) > at java.lang.ClassLoader.loadClass(ClassLoader.java:358) > at java.lang.Class.forName0(Native Method) > at java.lang.Class.forName(Class.java:190) > at > org.apache.spark.SparkContext$$anonfun$setupAndStartListenerBus$1.apply(SparkContext.scala:1694) > at > org.apache.spark.SparkContext$$anonfun$setupAndStartListenerBus$1.apply(SparkContext.scala:1691) > at > scala.collection.IndexedSeqOptimized$class.foreach(IndexedSeqOptimized.scala:33) > at scala.collection.mutable.WrappedArray.foreach(WrappedArray.scala:34) > at > org.apache.spark.SparkContext.setupAndStartListenerBus(SparkContext.scala:1691) > ... 9 more > Instead of > "val listenerClass = Class.forName(className)" in > SparkContext.setupAndStartListenerBus, we should use > "val listenerClass = Class.forName(className, true, > Thread.currentThread().getContextClassLoader)" > Note - this is a common pattern in spark, and might be relevant elsewhere too. -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org