More guidelines from the src:
http://www.slf4j.org/faq.html#logging_performance
I was thrilled reading "...the second form will outperform the first
form by a factor of at least 30..."
On 23/11/2012 15:18, Jonathan Ellis wrote:
I prefer the concise approach when no evaluation needs to be performed
on the method arguments, but when it does I prefer the explicit
isDebugEnabled check, or else reviewers need to think each time they
see one, "is this a hot code path where we can afford to be sloppy, or
not?"
On Fri, Nov 23, 2012 at 9:14 AM, Stephen Connolly
<stephen.alan.conno...@gmail.com> wrote:
On 22 November 2012 17:51, Radim Kolar <h...@filez.com> wrote:
instead of this:
if (logger.isDebugEnabled())
logger.debug("INDEX LOAD TIME for " + descriptor + ": " +
(System.currentTimeMillis() - start) + " ms.");
do this:
logger.debug("INDEX LOAD TIME for {} : {} ms.", descriptor,
(System.currentTimeMillis() - start));
Yes, but until/unless the JVM elides the function call because that logger
is not enabled fro debug, you will incur the penalty of new
Object[]{string,new Long(System.currentTimeMillis() - start).
On top of that, when debug is enabled you incur the cost of formatting the
string, including the {} search & replace.
On a long running production system, you are correct that it should
*eventually* be equivalent, and I am not saying one way or the other
whether this should/shouldn't be changed... more just pointing out that
there are consequences to what might appear to be a trivial change... I'll
let the c* devs chime in as to what their strong opinion is in this regard
as they should have more experience handling high loads and I would love to
know which pattern I should be using in my code (FWIW I tend to favour your
approach to the if (debugEnabled) guard... but I always wonder ;-) )
-Stephen
easier to read.
