pinpoint-apm/pinpoint · warning

LoggerBinder is already initialized

Error message

LoggerBinder is already initialized

What it means

In Log4j2LoggingSystem.bindPluginLogFactory(), if PluginLogManager.initialize(binder) returns false, a binder is already registered, and 'LoggerBinder is already initialized' is warned. The call happens during profiler start; a second initialize means the plugin log factory was bound more than once in this classloader, usually because start() ran twice or another subsystem pre-bound the binder.

Source

Thrown at agent-module/profiler-logging/src/main/java/com/navercorp/pinpoint/profiler/logging/Log4j2LoggingSystem.java:150

            logger.info("{} stop", this.getClass().getSimpleName());
            this.binder.shutdown();
            if (loggerContext instanceof LifeCycle) {
                logger.info("{} loggerContext stop", this.getClass().getSimpleName());
                ((LifeCycle) loggerContext).stop();
            }
        }

    }


    private void bindPluginLogFactory(PluginLoggerBinder binder) {
        final String binderClassName = binder.getClass().getName();
        PluginLogger pluginLogger = binder.getLogger(binder.getClass().getName());
        pluginLogger.info("PluginLogManager.initialize() bind:{} cl:{}", binderClassName, binder.getClass().getClassLoader());
        // Set binder to static PluginLogManager
        // Should we unset binder at shutdown hook or stop()?
        if (!PluginLogManager.initialize(binder)) {
            pluginLogger.warn("LoggerBinder is already initialized");
        }
    }
}

View on GitHub (pinned to 744c3d3075)

Solutions

1. Ensure start() is called only once per classloader lifecycle (guard with started flag)
2. Call stop()/unregister before re-initializing
3. Check whether Log4j2LoggerBinderInitializer.beforeClass() also ran in the same JVM and remove the duplicate path
4. Verify only one profiler logging component is on the classpath

Example fix

// before
profilerLoggingSystem.start();
profilerLoggingSystem.start(); // warns 'already initialized'
// after
if (!started) { profilerLoggingSystem.start(); started = true; }

// guard start(): boolean alreadyBound = com.navercorp.pinpoint.profiler.logging.PluginLogManager.bound(); if (alreadyBound) skip initialize;

if (!PluginLogManager.initialize(binder)) { pluginLogger.warn("PluginLogManager already bound; skipping re-bind"); }

When it happens

Trigger: ProfilerLoggingSystem.start() invoked twice on the same agent classloader; an earlier component (e.g. Log4j2LoggerBinderInitializer) already registered a binder for the same classloader.

Common situations: Agent restart logic calling start() again without stop(); tests initializing both the logging system and the binder initializer; multiple agent modules in one JVM sharing a classloader.

Related errors

• LoggerBinder is already initialized
• 'log4j2-agent.xml' not found. agentPath:${profilePath}
• ProcessingEnvOptionsHolder not initialized yet.
• J9BootLoader create fail Caused by:
• initialize fail Caused by:

AI-assisted analysis of pinpoint-apm/pinpoint@744c3d3075 (2026-09-07). Data as JSON: /api/errors/90c63de53a6af5d3. Report an issue: GitHub.