While profiling a Fluo test running lots of little scans, I noticed a string builder operation showing up prominently in the profiling results. Below is a link to the problematic code. Calling range toString was the most expensive part followed by KeyExtent toString.
I am not sure if we can change this in 1.7 and 1.8/1.9 because people may rely on this for debugging. In 2.0 we may want to consider removing this (or moving it inside the logging code block).
Also, while looking at this I noticed that some of the log statements called String.format. Those should be placed in a if(llog.traceEnabled()) block.