Hi,

As i know, The debug check is done twice, once in the conditional test - then again in the debug() method. While doing this operation twice is probably trivial to the overall performance of the app. It is inefficient - and a poor use of CPU cycles. Slf4j provided “parameterized logging” which prevents string concatenation, and does the debug check only once.

I have done performance testing with using classic log back with slf4j API. I set LOG LEVEL is ERROR.

private static final Logger LOG = LoggerFactory.getLogger(MyClass.class);

Case 1:

if(LOG.isDebugEnabled())
{
   LOG.debug("any message from {}", myName);
}

Case :2 without isDebugEnabled Check

 LOG.debug("any message from {}", myName);

In Case 2, I found that classic logback takes time in checking DEBUG Enable.