为什么星火项目中的sbt程序集在“请通过提供sparkVersion和sparkComponents来添加任何火花依赖项”时失败？

Question

我在一个带有spark-cloudant依赖关系的sbt管理的Spark项目上工作。代码是 branch)。

我在build.sbt中添加了下面一行

"cloudant-labs" % "spark-cloudant" % "1.6.4-s_2.10" % "provided"

因此，build.sbt看起来如下：

name := "Movie Rating"

version := "1.0"

scalaVersion := "2.10.5"

libraryDependencies ++= {
  val sparkVersion =  "1.6.0"
  Seq(
     "org.apache.spark" %% "spark-core" % sparkVersion % "provided",
     "org.apache.spark" %% "spark-sql" % sparkVersion % "provided",
     "org.apache.spark" %% "spark-streaming" % sparkVersion % "provided",
     "org.apache.spark" %% "spark-streaming-kafka" % sparkVersion % "provided",
     "org.apache.spark" %% "spark-mllib" % sparkVersion % "provided",
     "org.apache.kafka" % "kafka-log4j-appender" % "0.9.0.0",
     "org.apache.kafka" % "kafka-clients" % "0.9.0.0",
     "org.apache.kafka" %% "kafka" % "0.9.0.0",
     "cloudant-labs" % "spark-cloudant" % "1.6.4-s_2.10" % "provided"
    )
}

assemblyMergeStrategy in assembly := {
  case PathList("org", "apache", "spark", xs @ _*) => MergeStrategy.first
  case PathList("scala", xs @ _*) => MergeStrategy.discard
  case PathList("META-INF", "maven", "org.slf4j", xs @ _* ) => MergeStrategy.first
  case x =>
    val oldStrategy = (assemblyMergeStrategy in assembly).value
    oldStrategy(x)
}

unmanagedBase <<= baseDirectory { base => base / "lib" }

assemblyOption in assembly := (assemblyOption in assembly).value.copy(includeScala = false)

当我执行sbt assembly时，我会得到以下错误：

java.lang.RuntimeException: Please add any Spark dependencies by 
   supplying the sparkVersion and sparkComponents. Please remove: 
   org.apache.spark:spark-core:1.6.0:provided

Answer 1

注意到我仍然不能重现这个问题，但我认为这并不重要。

java.lang.RuntimeException:请通过提供sparkVersion和sparkComponents来添加任何火花依赖项。

在您的示例中，您的build.sbt缺少一个sbt解析器来查找spark-cloudant依赖项。您应该在build.sbt中添加以下行

resolvers += "spark-packages" at "https://dl.bintray.com/spark-packages/maven/"

PROTIP我强烈建议您首先使用spark-shell，并且只在您满意将包切换到sbt (特别是sbt)时才使用。如果您对sbt以及其他库/依赖关系也不熟悉)。一口就消化太多了。跟着https://spark-packages.org/package/cloudant-labs/spark-cloudant走。

Answer 2

可能相关：https://github.com/databricks/spark-csv/issues/150

您能尝试将spIgnoreProvided := true添加到build.sbt中吗？

(这可能不是答案，我本可以发表评论，但我没有足够的声誉)