pinpoint-apm/pinpoint · warning

Unknown ShutdownHookRegister

Error message

Unknown ShutdownHookRegister : {}

What it means

WARN in ShutdownHookRegisterProvider.createShutdownHookRegister: the configured shutdown hook class was found via Class.forName but has no no-arg constructor (NoSuchMethodException), so the provider logs this and falls back to RUNTIME_SHUTDOWN_HOOK_REGISTER. The agent keeps running with the default runtime shutdown hook instead of the configured one.

Solutions

1. Add a public no-argument constructor to the configured ShutdownHookRegister class.
2. Verify the configured class name points to the intended implementation.
3. Accept the RUNTIME_SHUTDOWN_HOOK_REGISTER fallback if a custom hook is not required.

Example fix

// before
public class MyShutdownHookRegister implements ShutdownHookRegister {
  public MyShutdownHookRegister(String name) { ... }
}
// after
public class MyShutdownHookRegister implements ShutdownHookRegister {
  public MyShutdownHookRegister() { }
  public MyShutdownHookRegister(String name) { ... }
}

Class<?> c = Class.forName(className);
if (!ShutdownHookRegister.class.isAssignableFrom(c) || c.getConstructor() == null) {
    logger.warn("{} is not a usable ShutdownHookRegister (needs public no-arg ctor)", className);
}

boolean isUsableShutdownHookRegister(Class<?> c) {
    try {
        return ShutdownHookRegister.class.isAssignableFrom(c) && c.getConstructor() != null;
    } catch (NoSuchMethodException e) {
        return false;
    }
}

try {
    return createCustomShutdownHookRegister(className);
} catch (ReflectiveOperationException | IllegalArgumentException e) {
    logger.warn("Falling back to runtime shutdown hook register", e);
    return RUNTIME_SHUTDOWN_HOOK_REGISTER;
}

When it happens

Trigger: Setting the custom ShutdownHookRegister class name (profiler.shutdown.hook.register class config) to a class that lacks a public no-argument constructor.

Common situations: Custom ShutdownHookRegister implemented with only parameterized constructors; class changed API between versions; using a class from a different library that isn't a proper ShutdownHookRegister implementation.

Related errors

• access error
• injectField error field
• ModuleFactory initialize fail
• unsupported data type
• Unsupported type

AI-assisted analysis of pinpoint-apm/pinpoint@744c3d3075 (2026-09-07). Data as JSON: /api/errors/afc1d6a4c5124002. Report an issue: GitHub.

Appendix: source

Thrown at agent-module/profiler/src/main/java/com/navercorp/pinpoint/profiler/context/provider/ShutdownHookRegisterProvider.java:105

            return JDK7_SHUTDOWN_HOOK_REGISTER;
        }
        return null;
    }

    private ShutdownHookRegister createShutdownHookRegister(String classToLoad) {
        if (classToLoad == null) {
            return RUNTIME_SHUTDOWN_HOOK_REGISTER;
        }

        try {
            @SuppressWarnings("unchecked")
            Class<ShutdownHookRegister> shutdownHookRegisterClass = (Class<ShutdownHookRegister>) Class.forName(classToLoad);

            try {
                Constructor<ShutdownHookRegister> shutdownHookRegisterConstructorConstructor = shutdownHookRegisterClass.getConstructor();
                return shutdownHookRegisterConstructorConstructor.newInstance();
            } catch (NoSuchMethodException e) {
                logger.warn("Unknown ShutdownHookRegister : {}", classToLoad);
                return RUNTIME_SHUTDOWN_HOOK_REGISTER;
            }
        } catch (ReflectiveOperationException e) {
            logger.warn("Error creating ShutdownHookRegister [" + classToLoad + "]", e);
        }
        return RUNTIME_SHUTDOWN_HOOK_REGISTER;
    }

    private static class RuntimeShutdownHookRegister implements ShutdownHookRegister {

        private final Logger logger = LogManager.getLogger(this.getClass());

        @Override
        public void register(Thread thread) {
            Runtime.getRuntime().addShutdownHook(thread);
            logger.info("register() completed. (ShutdownHook registered in java.lang.Runtime.)");
        }

View on GitHub (pinned to 744c3d3075)