How to configure log4j and Selenium Grid?

When I launch a Grid hub using Ant, the logging is all by default on the console. I would like to know if there is a way wherein I can alter the build.xml file of Selenium Grid and inclu开发者_Python百科de a log4j logger into it. I understand that I can specify a log file to Ant itself using the -logfile option. But this would cause the log file to be overwritten everytime the grid is launched. I want to ensure that the log files are automatically renamed after a threshold is reached for better maintenance. Any help and if possible some examples on how to do it would be greatly appreciated (I am new to using log4j which is why I am asking for some sample for this specific need).

You need to specify the location of the Log4j archive as well as its configuration file when starting up Selenium. In the following example, I've updated the classpath to load the log4j.hub.properties configuration file located in the /etc/selenium directory and the log4j.jar located in the /usr/lib/selenium directory. I've also setup some additional log files:

java -classpath /etc/selenium:/usr/lib/selenium/log4j.jar:/usr/lib/selenium/selenium-server-standalone.jar -Dlog4j.configuration=log4j.hub.properties org.openqa.grid.selenium.GridLauncher -role hub -log /var/log/selenium/hub.debug.log > /var/log/selenium/hub.output.log 2> /var/log/selenium/hub.error.log &

Then you can have something like the following to achieve what you are looking for:

log4j.rootLogger=ALL, file

log4j.appender.file=org.apache.log4j.FileAppender
log4j.appender.file.File=/var/log/selenium/hub.log
log4j.appender.file.Append=true
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss,SSS} <%p> <%t> %m%n

You might want to look at this page for more information about how Selenium logging is working.