无法通过 Spark 连接到 Mongo DB [英] Can't connect to Mongo DB via Spark

问题描述

我正在尝试通过 Apache Spark master 从 Mongo DB 读取数据.

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

我为此使用了 3 台机器:

I'm using 3 machines for this:

• 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 - 带有连接到 M2 的 Spark master 的 python 应用程序

应用程序(M3)正在像这样获得与 spark master 的连接:

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)正在尝试从数据库读取数据:

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()

但由于此异常而失败:

    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 http://spark.apache.org/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 py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
        at py4j.commands.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.net.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 找不到 com.mongodb.spark.sql.DefaultSource 包，因此出现错误消息.

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

一切，其他看起来不错只需要包含 Mongo Spark 包:

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文件在正确的路径上.

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

确保检查您的 Spark 版本所需的 Mongo-Spark 包的版本:https://spark-packages.org/package/mongodb/mongo-spark

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

这篇关于无法通过 Spark 连接到 Mongo DB的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！