BIND 10 #2896: change some bind10 process logging from info to debug

[BIND 10 Development]

#2896: change some bind10 process logging from info to debug
-------------------------------------+-------------------------------------
            Reporter:  jreed         |                        Owner:
                Type:  defect        |                       Status:  new
            Priority:  low           |                    Milestone:  New
           Component:  Boss of BIND  |  Tasks
            Keywords:                |                   Resolution:
           Sensitive:  0             |                 CVSS Scoring:
         Sub-Project:  Core          |              Defect Severity:  N/A
Estimated Difficulty:  0             |  Feature Depending on Ticket:
         Total Hours:  0             |          Add Hours to Ticket:  0
                                     |                    Internal?:  0
-------------------------------------+-------------------------------------

Comment (by jinmei):

 - (As discussed on jabber) first off, I personally don't think it a
   very good idea to introduce custom alias of debug levels in an
   arbitrary manner like `DBG_COMMANDS`.  it will make it more
   difficult to unify the policy of choosing levels, for example.
   Fixing existing ones would be beyond the scope of this ticket, but I
   suggest using the original definitions such as
 `logger.DBGLVL_TRACE_BASIC`
   for new ones.
 - according to the description of log_dbglevels.h,
   `logger.DBGLVL_TRACE_BASIC` seems to be the best choice here.
 {{{#!python
         logger.debug(DBG_TRACE_DATA, BIND10_COMPONENT_STOP, self.name())
 }}}
   Stopping a component shouldn't be a frequent operation, so it
   wouldn't be at the "detail" level.
 - This one may not be that obvious:
 {{{#!diff
 -                logger.info(BIND10_PROCESS_ENDED, component.name(), pid,
 -                            exit_status)
 +                logger.debug(DBG_COMMANDS, BIND10_PROCESS_ENDED,
 +                             component.name(), pid, exit_status)
 }}}
   If the process died accidentally, I think that should be logged at
   least at the info level (I think it could even be an error because
   it's certainly an erroneous event for the entire BIND 10 system).  A
   cleaner way would be to use a separate log message, but if it's
   deemed to be too much for this ticket, I suggest to change the log
   level depending on the value of exit_status.  In the case it should
   be at debug, I suggest `logger.DBGLVL_TRACE_BASIC` like the previous
   one.

-- 
Ticket URL: <http://bind10.isc.org/ticket/2896#comment:1>
BIND 10 Development <http://bind10.isc.org>
BIND 10 Development