Livy interpreter : Long running job timeout

Launching a long running job (running time > livy session timeout) with the livy interpreter, like a file copy in spark, doesn't keep alive the livy session.

At the end of the livy session timeout set in the configuration, the session is killed and the job stopped.

Modifying the livy session timeout isn't a sustainable solution.

Idea : Keep alive the livy session while the job isn't finished (with the job PID)