| | 1 | The nodehandler uses four different levels of logging messages: |
| | 2 | |
| | 3 | * '''DEBUG''': |
| | 4 | Those are logging messages about various internal state changes which |
| | 5 | are mainly useful for the developers of nodehandler or for more in-depth |
| | 6 | analysis of what's going on. They should be of little use for the casual |
| | 7 | experimenter |
| | 8 | |
| | 9 | * '''INFO''': |
| | 10 | Those logging messages report state changes which we deemed useful to |
| | 11 | report to the experimenter. An info message does NOT report anything |
| | 12 | abnormal. Info messages, as the name implies inform the experimenter that |
| | 13 | the experiment is progressing and should be considered POSITIVE feedback. |
| | 14 | |
| | 15 | * '''WARNING''': |
| | 16 | Warning messages report abnormal behavior but it is still possible |
| | 17 | for the nodehandler to proceed. It is left to the experimenter to decide if |
| | 18 | it makes sense to proceed or if the experiment should be stopped. Warning |
| | 19 | messages usually originate from the nodes. There are mechanisms which would |
| | 20 | allow an experiment script to react to those messages and potentially take |
| | 21 | corrective actions. Right now, those mechanisms aren't fully developed and |
| | 22 | therefore not properly documented. |
| | 23 | |
| | 24 | * '''ERROR''': |
| | 25 | Error messages report unexpected behaviors by the nodehandler or some |
| | 26 | of its sub system. The progress of the experiment is undetermined. An error |
| | 27 | message usually results from an unprocessed exception. |
| | 28 | |
| | 29 | In short DEBUG and INFO are logging normal progress and can be ignored, WARN |
| | 30 | and ERROR report on abnormal behavior. |
| | 31 | |