Re: Cost of debug statements.

[Doug Cutting]

Raghu Angadi wrote:
if ( debugEnabled ) {
  NameNode.stateChangeLog.debug( ...
}

Yes, this is sometimes warranted.  I've also seen it abused, with, e.g., 
guards placed around all log statements.  I suggest the following 
guidelines:

Guards should only be used:
 1. in inner-loop code where performance is known to be critical; and
 2. for messages logged at a finer level than default (INFO), i.e., 
only for debug-level messages.

The case you mention seems to meet both of these criteria.  +1

Doug