Spark无法下载kafka库

Question

我正在通过Kafka使用Python 3.5和Spark 2.2流，并且由于缺少kafka库，脚本无法运行。

我感到困惑的是，即使依赖项信息来自Spark的网站本身，为什么也缺少/找不到该库。

groupId = org.apache.spark
artifactId = spark-streaming-kafka-0-10_2.11
version = 2.2.0

我运行了“ spark-submit script.py”，错误提示需要kafka库。

Spark Streaming's Kafka libraries not found in class path. Try one of the following.

  1. Include the Kafka library and its dependencies with in the
     spark-submit command as

     $ bin/spark-submit --packages org.apache.spark:spark-streaming-kafka-0-8:2.2.0 ...

  2. Download the JAR of the artifact from Maven Central http://search.maven.org/,
     Group Id = org.apache.spark, Artifact Id = spark-streaming-kafka-0-8-assembly, Version = 2.2.0.
     Then, include the jar in the spark-submit command as

     $ bin/spark-submit --jars <spark-streaming-kafka-0-8-assembly.jar> ...

在下一次运行中，我运行了带有要下载的kafka库的“ spark-submit --packages org.apache.spark：spark-streaming-kafka-0-10：2.2.0 script.py”。

这次，该错误表明它无法找到/下载该库。

Ivy Default Cache set to: C:\Users\james\.ivy2\cache
The jars for the packages stored in: C:\Users\james\.ivy2\jars
:: loading settings :: url = jar:file:/D:/programs/spark-2.2.0/jars/ivy-2.4.0.jar!/org/apache/ivy/core/settings/ivysettings.xml
org.apache.spark#spark-streaming-kafka-0-10 added as a dependency
:: resolving dependencies :: org.apache.spark#spark-submit-parent;1.0
        confs: [default]
:: resolution report :: resolve 2908ms :: artifacts dl 0ms
        :: modules in use:
        ---------------------------------------------------------------------
        |                  |            modules            ||   artifacts   |
        |       conf       | number| search|dwnlded|evicted|| number|dwnlded|
        ---------------------------------------------------------------------
        |      default     |   1   |   0   |   0   |   0   ||   0   |   0   |
        ---------------------------------------------------------------------

:: problems summary ::
:::: WARNINGS
                module not found: org.apache.spark#spark-streaming-kafka-0-10;2.2.0

        ==== local-m2-cache: tried

          file:/C:/Users/james/.m2/repository/org/apache/spark/spark-streaming-kafka-0-10/2.2.0/spark-streaming-kafka-0-10-2.2.0.pom

          -- artifact org.apache.spark#spark-streaming-kafka-0-10;2.2.0!spark-streaming-kafka-0-10.jar:

          file:/C:/Users/james/.m2/repository/org/apache/spark/spark-streaming-kafka-0-10/2.2.0/spark-streaming-kafka-0-10-2.2.0.jar

        ==== local-ivy-cache: tried

          C:\Users\james\.ivy2\local\org.apache.spark\spark-streaming-kafka-0-10\2.2.0\ivys\ivy.xml

          -- artifact org.apache.spark#spark-streaming-kafka-0-10;2.2.0!spark-streaming-kafka-0-10.jar:

          C:\Users\james\.ivy2\local\org.apache.spark\spark-streaming-kafka-0-10\2.2.0\jars\spark-streaming-kafka-0-10.jar

        ==== central: tried

          https://repo1.maven.org/maven2/org/apache/spark/spark-streaming-kafka-0-10/2.2.0/spark-streaming-kafka-0-10-2.2.0.pom

          -- artifact org.apache.spark#spark-streaming-kafka-0-10;2.2.0!spark-streaming-kafka-0-10.jar:

          https://repo1.maven.org/maven2/org/apache/spark/spark-streaming-kafka-0-10/2.2.0/spark-streaming-kafka-0-10-2.2.0.jar

        ==== spark-packages: tried

          http://dl.bintray.com/spark-packages/maven/org/apache/spark/spark-streaming-kafka-0-10/2.2.0/spark-streaming-kafka-0-10-2.2.0.pom

          -- artifact org.apache.spark#spark-streaming-kafka-0-10;2.2.0!spark-streaming-kafka-0-10.jar:

          http://dl.bintray.com/spark-packages/maven/org/apache/spark/spark-streaming-kafka-0-10/2.2.0/spark-streaming-kafka-0-10-2.2.0.jar

                ::::::::::::::::::::::::::::::::::::::::::::::

                ::          UNRESOLVED DEPENDENCIES         ::

                ::::::::::::::::::::::::::::::::::::::::::::::

                :: org.apache.spark#spark-streaming-kafka-0-10;2.2.0: not found

                ::::::::::::::::::::::::::::::::::::::::::::::



:: USE VERBOSE OR DEBUG MESSAGE LEVEL FOR MORE DETAILS
Exception in thread "main" java.lang.RuntimeException: [unresolved dependency: org.apache.spark#spark-streaming-kafka-0-10;2.2.0: not found]
        at org.apache.spark.deploy.SparkSubmitUtils$.resolveMavenCoordinates(SparkSubmit.scala:1177)
        at org.apache.spark.deploy.SparkSubmit$.prepareSubmitEnvironment(SparkSubmit.scala:298)
        at org.apache.spark.deploy.SparkSubmit$.submit(SparkSubmit.scala:153)
        at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:119)
        at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala)

Answer 1

第一：正如在Developers Mailing列表上所讨论的，Kafka不包含在二进制分发中。这就是为什么在classpath上没有它的原因。

第二：在--packages命令中，您应该指定Scala版本。它不仅在SBT中是必需的，而且spark-submit在后台使用Ivy。

因此，请尝试：

  $ bin/spark-submit --packages org.apache.spark:spark-streaming-kafka-0-10_2.11:2.2.0 script.py

重点：也许我会创建一个PR来更改描述，这会产生误导