On Thu, Jul 29, 2010 at 4:35 AM, Armin Hornung
<HornungA@informatik.uni-freiburg.de> wrote:
> This discussion made me wonder, should all logdebug statements be removed
> from python nodes which still run in boxturtle and are frequently called?
> I'm particularly worried about the performance of a low-powered robot that
> runs python nodes and communicates with a master over a weak wireless link.
> If I understand it correctly, then every rospy.logdebug(...) results in a
> callback of the python node to the master, which then writes it into its
> local logfile?

There are several misunderstandings here. rospy has two logging
levels: one for its local log file, and one for /rosout. The /rosout
logging level has been INFO. The problem was that the local log file
level was DEBUG. Thus, the issue in question is related to rospy
writing to its own local log file. All nodes maintain a separate log
file for robustness. Also, to clarify, logging messages on /rosout are
transmitted to the /rosout node via normal message publication, not
via callbacks to the master.

The problem was are talking about is at least several orders of
magnitude less of an issue. Also, Python being Python, it's fairly
trivial to 'hot patch' any node in which this truly evidences itself
as a problem.

Yes, rospy should be upgraded to include the ability to external set
logging levels. The first ticket for this was aborted for C Turtle
because it looked like roscpp would need some tweaks as well if the
current services were really to be client-library standards. It will
probably be tackled again in D Turtle.

 - Ken