Hi, I had downloaded the logback version 0.9.2 sometime back and had done some performance comparison vis a vis log4j. At that time the tested call (logger.isDebugEnabled) was atleast 3 times faster in logback then log4j. But just today i downloaded the 0.9.5 version and it seems that due to some changes the performance has been hit . Now logback is a bit slower then log4j for the same call . (Although i must add that the performance of parameterized call has improved, and it now takes half of the time as compared to 0.9.2) I am pasting the code used for the test. - Mandeep ==================================================================================================== ==================================================================================================== package mandy.test.programs; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class LogTester2 { static Logger logbacklogger = LoggerFactory.getLogger(LogTester2.class); static org.apache.log4j.Logger log4jlogger = org.apache.log4j.Logger.getLogger(LogTester2.class); // How many times should we try to log: static int loop = 1000000; public static void main(String[] args) throws InterruptedException { initConfig(); // Let's run once for Just In Time compiler log4jDirectDebugCall(); log4jTestedDebugCall(); logbackDirectDebugCall(); logbackTestedDebugCall(); logbackParametrizedDebugCall(); // let's run the tests and display the results: long result1 = log4jDirectDebugCall(); long result2 = log4jTestedDebugCall(); long result3 = logbackDirectDebugCall(); long result4 = logbackTestedDebugCall(); long result5 = logbackParametrizedDebugCall(); System.out.println("###############################################"); System.out.println("Log4j direct debug call: " + result1); System.out.println("Log4j tested (isDebugEnabled) debug call: " + result2); System.out.println("Logback direct debug call: " + result3); System.out.println("Logback tested (isDebugEnabled) debug call: " + result4); System.out.println("Logback parametrized debug call: " + result5); System.out.println("###############################################"); } private static long log4jDirectDebugCall() { Integer j = new Integer(2); long start = System.nanoTime(); for (int i = 0; i < loop; i++ ) { log4jlogger.debug("SEE IF THIS IS LOGGED " + j + "."); } return (System.nanoTime() - start) / loop; } private static long log4jTestedDebugCall() { Integer j = new Integer(2); long start = System.nanoTime(); for (int i = 0; i < loop; i++ ) { if (log4jlogger.isDebugEnabled()) { log4jlogger.debug("SEE IF THIS IS LOGGED " + j + "."); } } return (System.nanoTime() - start) / loop; } private static long logbackDirectDebugCall() { Integer j = new Integer(2); long start = System.nanoTime(); for (int i = 0; i < loop; i++ ) { logbacklogger.debug("SEE IF THIS IS LOGGED " + j + "."); } return (System.nanoTime() - start) / loop; } private static long logbackTestedDebugCall() { Integer j = new Integer(2); long start = System.nanoTime(); for (int i = 0; i < loop; i++ ) { if (logbacklogger.isDebugEnabled()) logbacklogger.debug("SEE IF THIS IS LOGGED " + j + "."); } return (System.nanoTime() - start) / loop; } private static long logbackParametrizedDebugCall() { Integer j = new Integer(2); long start = System.nanoTime(); for (int i = 0; i < loop; i++ ) { logbacklogger.debug("SEE IF THIS IS LOGGED {}.", j); } return (System.nanoTime() - start) / loop; } private static void initConfig() { org.apache.log4j.Logger log4jRoot = org.apache.log4j.Logger.getRootLogger(); log4jRoot.setLevel(org.apache.log4j.Level.INFO); ch.qos.logback.classic.Logger lbRoot = (ch.qos.logback.classic.Logger) LoggerFactory.getLogger("ROOT"); lbRoot.setLevel(ch.qos.logback.classic.Level.INFO); // create the loggers org.apache.log4j.Logger.getLogger("perfTest"); org.apache.log4j.Logger.getLogger("perfTest.ch"); org.apache.log4j.Logger.getLogger("perfTest.ch.qos"); org.apache.log4j.Logger.getLogger("perfTest.ch.qos.logback"); LoggerFactory.getLogger("perfTest"); LoggerFactory.getLogger("perfTest.ch"); LoggerFactory.getLogger("perfTest.ch.qos"); LoggerFactory.getLogger("perfTest.ch.qos.logback"); } } ____________________________________________________________________________________Need a vacation? Get great deals to amazing places on Yahoo! Travel. http://travel.yahoo.com/