无法通过Spark连接到Mongo DB

本文介绍了无法通过Spark连接到Mongo DB的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我正在尝试通过Apache Spark主数据库从Mongo DB中读取数据.

I'm trying to read data from Mongo DB through an Apache Spark master.

我为此使用3台机器

• M1-上面有一个Mongo数据库实例
• M2-带有Spark Master，带有Mongo连接器，在其上运行
• M3-具有连接到M2的Spark主控件的python应用程序

应用程序(M3)正在与Spark Master连接，如下所示:

The application(M3) is getting a connection to the spark master like this:

_sparkSession = SparkSession.builder.master(masterPath).appName(appName)\ .config("spark.mongodb.input.uri", "mongodb://10.0.3.150/db1.data.coll")\ .config("spark.mongodb.output.uri", "mongodb://10.0.3.150/db1.data.coll").getOrCreate()

应用程序(M3)试图从数据库中读取数据:

The application(M3) is trying to read data from the DB:

sqlContext = SQLContext(_sparkSession.sparkContext) df = sqlContext.read.format("com.mongodb.spark.sql.DefaultSource").option("uri","mongodb://user:pass@10.0.3.150/db1.data?readPreference=primaryPreferred").load()

但由于以下异常而失败:

but fails with this exception:

py4j.protocol.Py4JJavaError: An error occurred while calling o56.load. : java.lang.ClassNotFoundException: Failed to find data source: com.mongodb.spark.sql.DefaultSource. Please find packages at spark.apache/third-party-projects.html at org.apache.spark.sql.execution.datasources.DataSource$.lookupDataSource(DataSource.scala:594) at org.apache.spark.sql.execution.datasources.DataSource.providingClass$lzycompute(DataSource.scala:86) at org.apache.spark.sql.execution.datasources.DataSource.providingClass(DataSource.scala:86) at org.apache.spark.sql.execution.datasources.DataSource.resolveRelation(DataSource.scala:325) at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:152) at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:125) 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 py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244) at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357) at py4j.Gateway.invoke(Gateway.java:280) at py4jmands.AbstractCommand.invokeMethod(AbstractCommand.java:132) at py4jmands.CallCommand.execute(CallCommand.java:79) at py4j.GatewayConnection.run(GatewayConnection.java:214) at java.lang.Thread.run(Thread.java:748) Caused by: java.lang.ClassNotFoundException: com.mongodb.spark.sql.DefaultSource.DefaultSource at java.URLClassLoader.findClass(URLClassLoader.java:381) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) at org.apache.spark.sql.execution.datasources.DataSource$$anonfun$25$$anonfun$apply$13.apply(DataSource.scala:579) at org.apache.spark.sql.execution.datasources.DataSource$$anonfun$25$$anonfun$apply$13.apply(DataSource.scala:579) at scala.util.Try$.apply(Try.scala:192) at org.apache.spark.sql.execution.datasources.DataSource$$anonfun$25.apply(DataSource.scala:579) at org.apache.spark.sql.execution.datasources.DataSource$$anonfun$25.apply(DataSource.scala:579) at scala.util.Try.orElse(Try.scala:84) at org.apache.spark.sql.execution.datasources.DataSource$.lookupDataSource(DataSource.scala:579) ... 16 more

推荐答案

Spark无法找到com.mongodb.spark.sql.DefaultSource程序包，因此会出现错误消息.

Spark can't find the com.mongodb.spark.sql.DefaultSource package, hence the error message.

一切都不错，只需要包括Mongo Spark软件包即可:

Everything, else looks good just need to include the Mongo Spark package:

> $SPARK_HOME/bin/pyspark --packages org.mongodb.spark:mongo-spark-connector_2.11:2.2.0

或者确保jar文件位于正确的路径上.

Or ensure that the jar file is on the correct path.

请确保您检查了您的Spark版本所需的Mongo-Spark软件包的版本: spark-packages/package/mongodb/mongo-spark

Make sure you check the version of the Mongo-Spark package required for your version of Spark: spark-packages/package/mongodb/mongo-spark