I would like to switch on the debug log level of the namenode (or other components) without restarting it. This is needed to analyze a production system.
Can somebody please advice on how to set the loglevel dyncamically on a running namenode? I was thinking of enhancing dfsadmin to make an RPC to the namenode to set a specified logging level. But the apache common logging APi does not export an API to change logging levels.