Trivial Description
This is a small starter task to help new contributors practice the pull request and code review process.
The Maven module common/network-shuffle does not have a log4j configuration file for its test cases. Usually these configuration files are located inside each module, in the directory src/test/resources. The missing configuration file leads to a scary-looking but harmless series of errors and stack traces in Spark build logs:
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
log4j:ERROR Could not read configuration file from URL [file:src/test/resources/log4j.properties].
java.io.FileNotFoundException: src/test/resources/log4j.properties (No such file or directory)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(FileInputStream.java:146)
at java.io.FileInputStream.<init>(FileInputStream.java:101)
at sun.net.www.protocol.file.FileURLConnection.connect(FileURLConnection.java:90)
at sun.net.www.protocol.file.FileURLConnection.getInputStream(FileURLConnection.java:188)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:557)
at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionConverter.java:526)
at org.apache.log4j.LogManager.<clinit>(LogManager.java:127)
at org.apache.log4j.Logger.getLogger(Logger.java:104)
at io.netty.util.internal.logging.Log4JLoggerFactory.newInstance(Log4JLoggerFactory.java:29)
at io.netty.util.internal.logging.InternalLoggerFactory.newDefaultFactory(InternalLoggerFactory.java:46)
at io.netty.util.internal.logging.InternalLoggerFactory.<clinit>(InternalLoggerFactory.java:34)
...
