錯誤yarn.ApplicationMaster：用戶類引發異常：java.lang.NoClassDefFoundError：scala / Function0 $ class

Question

我正在嘗試通過Apache Livy將Spark作業提交給hadoop-yarn集群。 使用此處指定的步驟設置集群。

Java代碼正在Windows本地計算機上通過IntelliJ運行。 spark和hadoop群集位於linux服務器上。 其他應用程序（不帶Livy）通過hdfs上的操作和spark計算可以完美運行。

我正在嘗試在群集的應用程序的stderr中看到錯誤日志：

INFO yarn.ApplicationMaster: Waiting for spark context initialization...
INFO driver.RSCDriver: Connecting to: master:10000
INFO driver.RSCDriver: Starting RPC server...
INFO rpc.RpcServer: Connected to the port 10001
WARN rsc.RSCConf: Your hostname, master, resolves to a loopback address, but we couldn't find any external IP address!
WARN rsc.RSCConf: Set livy.rsc.rpc.server.address if you need to bind to another address.
INFO driver.RSCDriver: Received job request 37e4684d-9de2-4a4b-9506-0b10a3e78a51
INFO driver.RSCDriver: SparkContext not yet up, queueing job request.
ERROR yarn.ApplicationMaster: User class threw exception: java.lang.NoClassDefFoundError: scala/Function0$class
java.lang.NoClassDefFoundError: scala/Function0$class
    at org.apache.livy.shaded.json4s.ThreadLocal.<init>(Formats.scala:311)
    at org.apache.livy.shaded.json4s.DefaultFormats$class.$init$(Formats.scala:318)
    at org.apache.livy.shaded.json4s.DefaultFormats$.<init>(Formats.scala:296)
    at org.apache.livy.shaded.json4s.DefaultFormats$.<clinit>(Formats.scala)
    at org.apache.livy.repl.Session.<init>(Session.scala:66)
    at org.apache.livy.repl.ReplDriver.initializeSparkEntries(ReplDriver.scala:41)
    at org.apache.livy.rsc.driver.RSCDriver.run(RSCDriver.java:333)
    at org.apache.livy.rsc.driver.RSCDriverBootstrapper.main(RSCDriverBootstrapper.java:93)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.spark.deploy.yarn.ApplicationMaster$$anon$2.run(ApplicationMaster.scala:684)
Caused by: java.lang.ClassNotFoundException: scala.Function0$class
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 13 more
INFO yarn.ApplicationMaster: Final app status: FAILED, exitCode: 13, (reason: User class threw exception: java.lang.NoClassDefFoundError: scala/Function0$class
    at org.apache.livy.shaded.json4s.ThreadLocal.<init>(Formats.scala:311)
    at org.apache.livy.shaded.json4s.DefaultFormats$class.$init$(Formats.scala:318)
    at org.apache.livy.shaded.json4s.DefaultFormats$.<init>(Formats.scala:296)
    at org.apache.livy.shaded.json4s.DefaultFormats$.<clinit>(Formats.scala)
    at org.apache.livy.repl.Session.<init>(Session.scala:66)
    at org.apache.livy.repl.ReplDriver.initializeSparkEntries(ReplDriver.scala:41)
    at org.apache.livy.rsc.driver.RSCDriver.run(RSCDriver.java:333)
    at org.apache.livy.rsc.driver.RSCDriverBootstrapper.main(RSCDriverBootstrapper.java:93)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.spark.deploy.yarn.ApplicationMaster$$anon$2.run(ApplicationMaster.scala:684)
Caused by: java.lang.ClassNotFoundException: scala.Function0$class
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 13 more
)

提交Spark作業的java代碼：

URI uri = new URI("http", "username:password" , "host" , 8998, "", null, null);

Map<String,String> config = new HashMap<>();
config.put("spark.app.name","livy-poc");
config.put("livy.client.http.connection.timeout", "180s");
config.put("spark.driver.memory", "1g");

LivyClient client = new LivyClientBuilder(true).setURI(uri).setAll(config).build();

try {
    client.addJar(new URI("/path_to_jars/spark-core_2.12-2.4.2.jar")).get();
    client.addJar(new URI("/path_to_jars/scala-library-2.12.8.jar")).get();
    client.addJar(new URI("/path_to_jars/ThisJavaCode.jar")).get();

    System.out.printf("Running PiJob with %d samples...\n", 2);
    double pi = client.submit(new PiJob(2)).get();
    System.out.println("Pi is roughly: " + pi);
} catch (InterruptedException | ExecutionException e) {
    e.printStackTrace();
} finally {
    client.stop(true);
}
}

livy.conf文件具有：

# What spark master Livy sessions should use.
livy.spark.master = yarn
# What spark deploy mode Livy sessions should use.
livy.spark.deployMode = cluster

如果我錯過了什么，可以說出一點嗎？

Answer 1

Livy似乎僅支持針對Scala 2.11.x構建的Spark版本。 參見https://issues.apache.org/jira/browse/LIVY-423 。

更改您的client.addJar(...行以包括Scala 2.11版本和針對2.11構建的Spark發行版。