How to rebuild apache Livy with scala 2.12

I'm using Spark 3.1.1 which uses Scala 2.12, and the pre-built Livy downloaded from here uses Scala 2.11 (one could find the folder named repl_2.11-jars/ after unzip).

Referred to the comment made by Aliaksandr Sasnouskikh, Livy needs to be rebuilt or it'll throw error {'msg': 'requirement failed: Cannot find Livy REPL jars.'} even in POST Session.

In the README.md, it mentioned:

By default Livy is built against Apache Spark 2.4.5

If I'd like to rebuild Livy, how could I change the spark version that it is built with?

Thanks in advance.

Solution

You can rebuild Livy passing spark-3.0 profile in maven to create a custom build for spark 3, for example:

git clone https://github.com/apache/incubator-livy.git && \
cd incubator-livy && \
mvn clean package -B -V -e \
        -Pspark-3.0 \
        -Pthriftserver \
        -DskipTests \
        -DskipITs \
        -Dmaven.javadoc.skip=true

This profile is defined in pom.xml, the default one installs Spark 3.0.0. You can change it to use different spark version.

<profile>
      <id>spark-3.0</id>
      <activation>
        <property>
          <name>spark-3.0</name>
        </property>
      </activation>
      <properties>
        <spark.scala-2.12.version>3.0.0</spark.scala-2.12.version>
        <spark.scala-2.11.version>2.4.5</spark.scala-2.11.version>
        <spark.version>${spark.scala-2.11.version}</spark.version>
        <netty.spark-2.12.version>4.1.47.Final</netty.spark-2.12.version>
        <netty.spark-2.11.version>4.1.47.Final</netty.spark-2.11.version>
        <netty.version>${netty.spark-2.11.version}</netty.version>
        <java.version>1.8</java.version>
        <py4j.version>0.10.9</py4j.version>
        <json4s.spark-2.11.version>3.5.3</json4s.spark-2.11.version>
        <json4s.spark-2.12.version>3.6.6</json4s.spark-2.12.version>
        <json4s.version>${json4s.spark-2.11.version}</json4s.version>
        <spark.bin.download.url>
          https://archive.apache.org/dist/spark/spark-3.0.0/spark-3.0.0-bin-hadoop2.7.tgz
        </spark.bin.download.url>
        <spark.bin.name>spark-3.0.0-bin-hadoop2.7</spark.bin.name>
      </properties>
    </profile>

As long as I know, Livy supports spark 3.0.x. But worth testing with 3.1.1, and let us know :)