通过zeppelin从docker-hadoop-spark - workbench访问hdfs

Question

我安装了https://github.com/big-data-europe/docker-hadoop-spark-workbench

然后开始了docker-compose up.我导航到git自述文件中提到的各种网址,所有内容似乎都已启动.

然后我开始了一个本地的apache zeppelin:

./bin/zeppelin.sh start

在zeppelin解释器设置中,我已导航到spark解释器并更新master以指向安装的本地群集 docker

master:从更新local[*]到spark://localhost:8080

然后我在笔记本中运行以下代码:

import  org.apache.hadoop.fs.{FileSystem,Path}

FileSystem.get( sc.hadoopConfiguration ).listStatus( new Path("hdfs:///")).foreach( x => println(x.getPath ))

我在zeppelin日志中遇到此异常:

 INFO [2017-12-15 18:06:35,704] ({pool-2-thread-2} Paragraph.java[jobRun]:362) - run paragraph 20171212-200101_1553252595 using null org.apache.zeppelin.interpreter.LazyOpenInterpreter@32d09a20
 WARN [2017-12-15 18:07:37,717] ({pool-2-thread-2} NotebookServer.java[afterStatusChange]:2064) - Job 20171212-200101_1553252595 is finished, status: ERROR, exception: null, result: %text java.lang.NullPointerException
    at org.apache.zeppelin.spark.Utils.invokeMethod(Utils.java:38)
    at org.apache.zeppelin.spark.Utils.invokeMethod(Utils.java:33)
    at org.apache.zeppelin.spark.SparkInterpreter.createSparkContext_2(SparkInterpreter.java:398)
    at org.apache.zeppelin.spark.SparkInterpreter.createSparkContext(SparkInterpreter.java:387)
    at org.apache.zeppelin.spark.SparkInterpreter.getSparkContext(SparkInterpreter.java:146)
    at org.apache.zeppelin.spark.SparkInterpreter.open(SparkInterpreter.java:843)
    at org.apache.zeppelin.interpreter.LazyOpenInterpreter.open(LazyOpenInterpreter.java:70)
    at org.apache.zeppelin.interpreter.remote.RemoteInterpreterServer$InterpretJob.jobRun(RemoteInterpreterServer.java:491)
    at org.apache.zeppelin.scheduler.Job.run(Job.java:175)
    at org.apache.zeppelin.scheduler.FIFOScheduler$1.run(FIFOScheduler.java:139)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:748)

如何从zeppelin和java/spark代码访问hdfs？

Answer 1

异常的原因是该sparkSession对象null由于某种原因位于 Zeppelin 中。

参考： https: //github.com/apache/zeppelin/blob/master/spark/src/main/java/org/apache/zeppelin/spark/SparkInterpreter.java

private SparkContext createSparkContext_2() {
    return (SparkContext) Utils.invokeMethod(sparkSession, "sparkContext");
}

可能是与配置相关的问题。请交叉验证设置/配置和 Spark 集群设置。确保火花工作正常。

参考： https: //zeppelin.apache.org/docs/latest/interpreter/spark.html

希望这可以帮助。