This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Perhaps you are looking in the wrong place for those log files? I don't see anything wrong with what you posted, and it says to write the logs into the /logs folder. So do you have such a folder? Does your server have permission to write in it and create files in it?