It might be a permissions issue, these look promising from Google:
http://unix.stackexchange.com/questions ... same-grouphttp://stackoverflow.com/questions/2587 ... -in-log4j2For debugging, I'm asuming you have a firewall running and the port isn't open. I don't know what your client Os is but if it has telnet then try "telnet yourlinodeip thedebugportfortomcat". If it hangs then it's a firewall issue somewhere, your side, your ISP, your Linode
To get out of the telnet session in case it works, Ctrl+] then "close".