LoggingMXBean

By / 24 May 2025 / 2 minutes of reading

The LoggingMXBean is an interface in the java.lang.management package that allows monitoring and managing loggers in a Java application at runtime via JMX (Java Management Extensions).

It provides a way to dynamically inspect and change logging configurations (like log levels) without restarting the application.

Commonly Used Methods

Simple Program

import java.lang.management.ManagementFactory;
import java.util.List;
import java.util.logging.Logger;
import java.util.logging.Level;
import java.util.logging.LogManager;
import java.util.logging.LoggingMXBean;

public class LoggingMXBeanSimple {
    public static void main(String[] args) {
        Logger logger = Logger.getLogger("my.logger");
        logger.setLevel(Level.WARNING);

        LoggingMXBean mxBean = ManagementFactory.getPlatformMXBean(LoggingMXBean.class);

        System.out.println("Logger Names:");
        List<String> loggers = mxBean.getLoggerNames();
        for (String name : loggers) {
            if (name.equals("my.logger")) {
                System.out.println("Logger: " + name);
                System.out.println("Level: " + mxBean.getLoggerLevel(name));
                System.out.println("Parent: " + mxBean.getParentLoggerName(name));
            }
        }
    }
}

Real-Time Log Level Management in a Banking System

Problem Statement

LotusJavaPrince and Mahesh are building a banking backend that logs customer activities. During high load, they want to reduce logging verbosity to avoid IO overhead. Instead of restarting the server, they plan to use JMX and LoggingMXBean to dynamically change log levels using a monitoring tool like JConsole.

Program: Banking Logs with JMX Runtime Control
import java.lang.management.ManagementFactory;
import java.util.logging.*;

public class BankingActivityLogger {
    private static final Logger activityLogger = Logger.getLogger("bank.activity");

    public static void main(String[] args) throws InterruptedException {
        activityLogger.setLevel(Level.INFO);
        activityLogger.setUseParentHandlers(true);

        System.out.println("Use JConsole to connect and manage logging level dynamically.");
        System.out.println("Logger Name: bank.activity");

        while (true) {
            activityLogger.finest("DEBUG: Internal loop details");
            activityLogger.fine("FINE: Processing routine transaction...");
            activityLogger.info("INFO: LotusJavaPrince performed transaction");
            activityLogger.warning("WARNING: Mahesh attempted multiple logins");
            Thread.sleep(5000); // Simulate periodic logging
        }
    }
}

How to Use JConsole to Change Log Level

  1. Run the BankingActivityLogger program.

  2. Open JConsole (jconsole in terminal).

  3. Connect to the running Java process.

  4. Go to MBeans tab → java.util.logging → Logging.

  5. Use:

  • getLoggerNames() to find bank.activity.
  • getLoggerLevel("bank.activity")
  • setLoggerLevel("bank.activity", "SEVERE") to reduce output.

Outcome

Without restarting the app:

  • Set to FINE to increase log detail for debugging.

  • Set to WARNING to suppress info logs during high traffic.

LoggingMXBean enables dynamic management of loggers using JMX.This is Excellent for production systems where restarting isn’t an option.This Integrates with JConsole, VisualVM, and other JMX clients.Useful for real-time diagnostics, performance tuning, and auditing.

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