Java – performance of log4j

I am developing a web application. I want to record some information to help me improve and observe the application (I'm using Tomcat6)

First, I thought I would use stringbuilders to attach logs to them, and a task would continue to the database, just like every 2 minutes Because I'm worried about the performance of the out of the box recording system Then I did some tests Especially log4j

This is my code:

Main. java

public static void main(String[] args) {
  Thread[] threads = new Thread[LoggerThread.threadsNumber];

  for(int i = 0; i < LoggerThread.threadsNumber; ++i){
   threads[i] = new Thread(new LoggerThread("name - " + i));
  }
  LoggerThread.startTimestamp = System.currentTimeMillis();

  for(int i = 0; i < LoggerThread.threadsNumber; ++i){
   threads[i].start();
  }

LoggerThread. java

public class LoggerThread implements Runnable{
 public static int threadsNumber = 10;
 public static long startTimestamp;
 private static int counter = 0;
 private String name;

 public LoggerThread(String name) {
  this.name = name;
 }
 private Logger log = Logger.getLogger(this.getClass());

 @Override
 public void run() {
  for(int i=0; i<10000; ++i){
   log.info(name + ": " + i);

   if(i == 9999){
    int c = increaseCounter();

    if(c == threadsNumber){
     System.out.println("Elapsed time: " + 
       (System.currentTimeMillis() - startTimestamp));
    }
   }

  }
 }

 private synchronized int increaseCounter(){
  return ++counter;
 }

}
     }

log4j. properties

log4j.logger.main.LoggerThread=debug,f
log4j.appender.f=org.apache.log4j.RollingFileAppender
log4j.appender.f.layout=org.apache.log4j.PatternLayout
log4j.appender.f.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n
log4j.appender.f.File=c:/logs/logging.log
log4j.appender.f.MaxFileSize=15000KB
log4j.appender.f.MaxBackupIndex=50

I think this is a very common configuration of log4j First, I use log4j 1.2 Then I realized there was a newer version, so I switched to 1.2 sixteen

Here are numbers (all in milliseconds)

LoggerThread. threadsNumber = 10

1.2.14: 4235,4267,4328,4282
1.2.16: 2780,2781,2797,2781

LoggerThread. threadsNumber = 100

1.2.14: 41312,41014,42251
1.2.16: 25606,25729,25922

I think it's fast Don't forget: in each loop, the running method is not just logging into the file, it must connect the string (name ":" I) and check one if test (I = = 9999)

When threadsnumber is 10, there are 100.000 logs, if testing and connecting When it is 100, there is 1.000 000 log if testing and connecting I've read somewhere that the JVM uses additional connections from StringBuilder instead of simple connections

What did I miss? Did I do wrong? Did I forget anything that might degrade performance? If these numbers are correct, I don't think I have to worry about the performance of log4j, even if I log in a lot, right?

I read: "the typical cost of actual recording is about 100 to 300 microseconds." Is that right? (log4J manual)

Solution

Yes, log4j is considered fast because of the conscious efforts of its implementers See also the section "performance" at the end of this 07 / 08