Scala: Write log to file with log4j - scala

Question

I am trying to build a scala based jar file in eclipse that uses log4j to make logs. It prints out perfectly in the console but when I try to use log4j.properties file to make it write to a log file, nothing happens.
The project structure is as follows
loggerTest.scala
package scala.n*****.n****
import org.apache.log4j.Logger
object loggerTest extends LogHelper {
def main(args : Array[String]){
log.info("This is info");
log.error("This is error");
log.warn("This is warn");
}
}
trait LogHelper {
lazy val log = Logger.getLogger(this.getClass.getName)
}
log4j.properties
# Root logger option
log4j.rootLogger=WARN, stdout, file
# Redirect log messages to console
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
# Redirect log messages to a log file
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.File=/home/abc/test/abc.log
log4j.appender.file.encoding=UTF-8
log4j.appender.file.MaxFileSize=2kB
log4j.appender.file.MaxBackupIndex=1
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>loggerTest</groupId>
<artifactId>loggerTest</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>loggerTest</name>
<description>loggerTest</description>
<repositories>
<repository>
<id>scala-tools.org</id>
<name>Scala-tools Maven2 Repository</name>
<url>http://scala-tools.org/repo-releases</url>
</repository>
<repository>
<id>maven-hadoop</id>
<name>Hadoop Releases</name>
<url>https://repository.cloudera.com/content/repositories/releases/</url>
</repository>
<repository>
<id>cloudera-repos</id>
<name>Cloudera Repos</name>
<url>https://repository.cloudera.com/artifactory/cloudera-repos/</url>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>scala-tools.org</id>
<name>Scala-tools Maven2 Repository</name>
<url>http://scala-tools.org/repo-releases</url>
</pluginRepository>
</pluginRepositories>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
</properties>
<build>
<plugins>
<!-- mixed scala/java compile -->
<plugin>
<groupId>org.scala-tools</groupId>
<artifactId>maven-scala-plugin</artifactId>
<executions>
<execution>
<id>compile</id>
<goals>
<goal>compile</goal>
</goals>
<phase>compile</phase>
</execution>
<execution>
<id>test-compile</id>
<goals>
<goal>testCompile</goal>
</goals>
<phase>test-compile</phase>
</execution>
<execution>
<phase>process-resources</phase>
<goals>
<goal>compile</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>fully.qualified.MainClass</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
<pluginManagement>
<plugins>
<!--This plugin's configuration is used to store Eclipse m2e settings
only. It has no influence on the Maven build itself. -->
<plugin>
<groupId>org.eclipse.m2e</groupId>
<artifactId>lifecycle-mapping</artifactId>
<version>1.0.0</version>
<configuration>
<lifecycleMappingMetadata>
<pluginExecutions>
<pluginExecution>
<pluginExecutionFilter>
<groupId>org.scala-tools</groupId>
<artifactId>
maven-scala-plugin
</artifactId>
<versionRange>
[2.15.2,)
</versionRange>
<goals>
<goal>compile</goal>
<goal>testCompile</goal>
</goals>
</pluginExecutionFilter>
<action>
<execute></execute>
</action>
</pluginExecution>
</pluginExecutions>
</lifecycleMappingMetadata>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
<dependencies>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-core_2.10</artifactId>
<version>1.5.0</version>
</dependency>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-hive_2.10</artifactId>
<version>1.5.0</version>
</dependency>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-sql_2.10</artifactId>
<version>1.5.0</version>
</dependency>
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-library</artifactId>
<version>2.10.4</version>
</dependency>
</dependencies>
</project>
When I run it as a maven build, it generates a jar file in "target" folder.
I copy the jar to /home/abc/test
I run that jar in spark shell with command
$ spark-submit --class scala.n*****.n*****.loggerTest loggerTest-0.0.1-SNAPSHOT.jar
The console come out alright but it should write to a file in /home/abc/log which it does not.
Could someone please help?

Answer 1

Hello while you are deploying you application you should define log4j file for executor and driver as follows
spark-submit --class MAIN_CLASS --driver-java-options "-Dlog4j.configuration=file:PATH_OF_LOG4J" --conf "spark.executor.extraJavaOptions=-Dlog4j.configuration=file:PATH_OF_LOG4J" --master MASTER_IP:PORT JAR_PATH
For more details and step by step solution you can check this link https://blog.knoldus.com/2016/02/23/logging-spark-application-on-standalone-cluster/