使用Spark SQL从Spring Boot应用程序与Avro

Question

我正在尝试编写一个Spring Boot应用程序，该应用程序对Spark主服务器运行Spark SQL查询。下面是应该运行查询的代码:

public class SparkJob {
    public void run() {
        SparkConf conf = new SparkConf()
            .setMaster("spark://10.20.30.50:7077")
            .setAppName("show_avro_data");
        JavaSparkContext sc = new JavaSparkContext(conf);
        SQLContext sqlContext = new SQLContext(sc);
        DataFrame df = sqlContext.read()
            .format("com.databricks.spark.avro")
            .load("hdfs://localhost:8020/test.avro");
        df.show();
    }
}

run()方法是从Spring-MVC控制器内部调用的。它应该"在线"执行Spark查询-即我不想将应用程序上传到Spark，例如使用spark-submit。

当我现在启动应用程序并运行该方法时，我得到以下堆栈跟踪:

2016-11-08 17:38:18.805 ERROR 43109 --- [nio-9003-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]: 
  Servlet.service() for servlet [dispatcherServlet] in context with path [] 
  threw exception [Request processing failed; nested exception is 
  org.apache.spark.SparkException: Job aborted due to stage failure: 
  Task 0 in stage 0.0 failed 4 times, most recent failure: 
  Lost task 0.3 in stage 0.0 (TID 3, 10.20.30.50): 
  java.lang.ClassNotFoundException:
  com.databricks.spark.avro.AvroRelation$$anonfun$buildScan$1$$anonfun$3
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:348)
    at org.apache.spark.serializer.JavaDeserializationStream$$anon$1.resolveClass(JavaSerializer.scala:67)
    at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1620)
    at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1521)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1781)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2018)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1942)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2018)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1942)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2018)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1942)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:373)
    at scala.collection.immutable.$colon$colon.readObject(List.scala:362)
    at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1058)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1909)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2018)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1942)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2018)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1942)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.readArray(ObjectInputStream.java:1714)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1347)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2018)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1942)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2018)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1942)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2018)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1942)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:373)
    at scala.collection.immutable.$colon$colon.readObject(List.scala:362)
    at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1058)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1909)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2018)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1942)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2018)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1942)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:373)
    at scala.collection.immutable.$colon$colon.readObject(List.scala:362)
    at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:1058)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1909)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2018)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1942)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2018)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1942)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1808)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1353)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:373)
    at org.apache.spark.serializer.JavaDeserializationStream.readObject(JavaSerializer.scala:72)
    at org.apache.spark.serializer.JavaSerializerInstance.deserialize(JavaSerializer.scala:98)
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:61)
    at org.apache.spark.scheduler.Task.run(Task.scala:88)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:214)
    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:745)

由于我使用Spark版本1.5.2和Scala版本2.10.4，我根据Spark -avro文档使用了以下Maven依赖项:

<dependency>
    <groupId>org.apache.spark</groupId>
    <artifactId>spark-core_2.10</artifactId>
    <version>1.5.2</version>
</dependency>
<dependency>
    <groupId>org.apache.spark</groupId>
    <artifactId>spark-sql_2.10</artifactId>
    <version>1.5.2</version>
</dependency>
<dependency>
    <groupId>com.databricks</groupId>
    <artifactId>spark-avro_2.10</artifactId>
    <version>2.0.1</version>
</dependency>

我猜，我不知何故必须在Spark主上提供Avro库-但我不知道，如何做到这一点，我能在互联网上找到的所有示例都没有提供任何解决这个问题的方法。

编辑

应用程序工作正常，当我使用JSON代替Avro与

DataFrame df = sqlContext.read().json("hdfs://...");

Answer 1

由于您正在从您的spring应用程序调用spark(您不使用spark-submit)，您正试图使用MVC作为"驱动程序"并在独立spark上运行spark作业。

所以您想使用spring MVC作为驱动程序并在client模式下。对吧?

下面的依赖关系只是在你的MVC spring project(在spark驱动client端)，所以你需要把这个库添加到spark standalone(到worker)。

<dependency>
    <groupId>com.databricks</groupId>
    <artifactId>spark-avro_2.10</artifactId>
    <version>2.0.1</version>
</dependency>

您可以将spark-avro_2.10.jar添加到HDFS中，也可以将SparkContext添加到HDFS中，例如:

 JavaSparkContext sc = new JavaSparkContext(conf);
 sc.addJar("pathToAvroOnHDFS/spark-avro_2.10.jar")

现在spark意识到spark-avro_2.10.jar。

另一种选择是将jar添加到spark类路径中。您可以检查以下属性(这些也应该在spark 1.5.2中支持):

spark.driver.extraClassPath /avroPath.jar
spark.executor.extraClassPath /avroPath.jar