Enclosing calls to debug() in if isDebugEnabled(): a good policy?

Question

Our team has the policy of doing logging like

if (LOGGER.isDebugEnabled()) {     LOGGER.debug("model[" + model + "]"); } 

instead of simply calling the logging method like this:

LOGGER.debug("model[" + model + "]"); 

This practice is capable of leading to some performance improvement, but on the other hand it makes the codebase more complex. Our application has no performance problems, probably never will, the argument for the introduction of the policy was simply that it's a good practice, so it shall be used every time we are doing logging.

Do you think it's a good policy?

Answer 1

You should use SLF4J and make log4j your implementation. With SLF4J, you can eliminate isDebugEnabled() altogether by using parameterized messages.

See the section about logging performance in the slf4j FAQ

The following two lines will yield the exact same output. However, the second form will outperform the first form by a factor of at least 30, in case of a disabled logging statement.

logger.debug("The new entry is " + entry + ".");

logger.debug("The new entry is {}.", entry);