build.sbt: how to add spark dependencies

Question

Hello I am trying to download spark-core, spark-streaming, twitter4j, and spark-streaming-twitter in the build.sbt file below:

name := "hello"

version := "1.0"

scalaVersion := "2.11.8"

libraryDependencies += "org.apache.spark" %% "spark-core" % "1.6.1"
libraryDependencies += "org.apache.spark" % "spark-streaming_2.10" % "1.4.1"

libraryDependencies ++= Seq(
  "org.twitter4j" % "twitter4j-core" % "3.0.3",
  "org.twitter4j" % "twitter4j-stream" % "3.0.3"
)

libraryDependencies += "org.apache.spark" % "spark-streaming-twitter_2.10" % "0.9.0-incubating"

I simply took this libraryDependencies online so I am not sure which versions, etc. to use.

Can someone please explain to me how I should fix this .sbt files. I spent a couple hours trying to figure it out but none of the suggesstion worked. I installed scala through homebrew and I am on version 2.11.8

All of my errors were about:

Modules were resolved with conflicting cross-version suffixes.

Answer 1

The problem is that you are mixing Scala 2.11 and 2.10 artifacts. You have:

scalaVersion := "2.11.8"

And then:

libraryDependencies += "org.apache.spark" % "spark-streaming_2.10" % "1.4.1"

Where the 2.10 artifact is being required. You are also mixing Spark versions instead of using a consistent version:

// spark 1.6.1
libraryDependencies += "org.apache.spark" %% "spark-core" % "1.6.1"

// spark 1.4.1
libraryDependencies += "org.apache.spark" % "spark-streaming_2.10" % "1.4.1"

// spark 0.9.0-incubating
libraryDependencies += "org.apache.spark" % "spark-streaming-twitter_2.10" % "0.9.0-incubating"

Here is a build.sbt that fixes both problems:

name := "hello"

version := "1.0"

scalaVersion := "2.11.8"

val sparkVersion = "1.6.1"

libraryDependencies ++= Seq(
  "org.apache.spark" %% "spark-core" % sparkVersion,
  "org.apache.spark" %% "spark-streaming" % sparkVersion,
  "org.apache.spark" %% "spark-streaming-twitter" % sparkVersion
)

You also don't need to manually add twitter4j dependencies since they are added transitively by spark-streaming-twitter.