The brute solution [If you are not logged in after running the command ]: ssh to that machine and then find the process id (pid) of the process that you want to kill by running the ps ax | grep <any part of the command that you ran> [e.g. ps ax | grep java]. After that a simple kill <pid> should do the trick.

The easier solution [If you are still in the console of that machine after running the command]: do a simple fg, that'd bring the process to the foreground and later you can do a ctrl + c. Or you can follow the similar process of finding the pid and killing the same.

Reply in case you need more assistance.

The brute solution [If you are not logged in after running the command ]: ssh to that machine and then find the process id (pid) of the process that you want to kill by running the ps ax | grep <any regex part of the command that you ran> [e.g. ps ax | grep java]. After that a simple kill <pid> should do the trick.

The easier solution [If you are still in the console of that machine after running the command]: do a simple fg, that'd bring the process to the foreground and later you can do a ctrl + c. Or you can follow the similar process of finding the pid and killing the same.

Reply in case you need more assistance.