在Wildfly上通过Startup bean中的JMX通过AttributeNotFoundException

Question

Hello everyone! I'm trying to load wildfly server's system properties through JMX in Startup bean's @PostConstruct method. It works fine on the already started server instance when deployment starts, but fails while starting with server instance bootstrapping.

Wildfly 11.0.0.CR1 Startup bean code:

package ru.wildfly.test.ejb.wildflyconsulregistrar.startup;
import ru.wildfly.test.ejb.wildflyconsulregistrar.api.ConsulRegistrar;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.ejb.Singleton;
import javax.ejb.Startup;
import javax.inject.Inject;

@Startup
@Singleton
public class WildflyConsulRegistrarStartupBean {

    @Inject
    private ConsulRegistrar consulRegistrar;

    @PostConstruct
    public void initialize() {
        registerServices();
    }

    private void registerServices() {
        consulRegistrar.registerService("WildflyTestCluster");
    }


    .............
}

ConsulRegistrar code:

package ru.wildfly.test.ejb.wildflyconsulregistrar.impl;

import com.ecwid.consul.v1.ConsulClient;
import com.ecwid.consul.v1.agent.model.NewService;
import ru.test.ejb.wildflyconsulregistrar.api.ConsulRegistrar;
import ru.wildfly.test.ejb.wildflyconsulregistrar.serversettings.api.CurrentServerNodeSettings;

import javax.annotation.PostConstruct;
import javax.enterprise.context.Dependent;
import javax.inject.Inject;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.List;

@Dependent
public class ConsulRegistrarImpl implements ConsulRegistrar {

    ...............

    @Inject
    private CurrentServerNodeSettings currentServerNodeSettings;

    .............

    @Override
    public void registerService(String serviceName) {
        String currentNodeName = currentServerNodeSettings.getCurrentNodeName();
        ........................
    }

    .......................

}

CurrentServerNodeSettings code:

package ru.wildfly.test.ejb.wildflyconsulregistrar.serversettings.impl;


import ru.wildfly.test.ejb.wildflyconsulregistrar.serversettings.api.CurrentServerNodeSettings;

import javax.enterprise.context.Dependent;
import javax.management.MBeanServer;
import javax.management.ObjectName;
import java.lang.management.ManagementFactory;

@Dependent
public class CurrentServerNodeSettingsWildflyImpl implements CurrentServerNodeSettings {

    ....................

    @Override
    public String getCurrentNodeName() {
        String currentNodeName =  getPlatformMBeanServerAttributeValue(String.class, "jboss.as:system-property=server.name", "value");
        return currentNodeName;
    }

    private <T> T getPlatformMBeanServerAttributeValue(Class<T> valueType, String objectName, String attributeName) {
        T attributeValue = null;

        try {
            MBeanServer mBeanServer = ManagementFactory.getPlatformMBeanServer();
            Object attributeObject = mBeanServer.getAttribute(new ObjectName(objectName), attributeName);

            attributeValue = attributeObject != null ? (valueType.cast(attributeObject)) : null;
        } catch (Exception ex) {
            throw new IllegalStateException(ex);
        }

        return attributeValue;
    }
}

Error message:

Caused by: java.lang.IllegalStateException: 
javax.management.AttributeNotFoundException: 
"WFLYCTL0216: Management resource '[(\"system-property\" => \"server.name\")]' not found"
at ru.wildfly.test.ejb.wildflyconsulregistrar.serversettings.impl.CurrentServerNodeSettingsWildflyImpl
.getPlatformMBeanServerAttributeValue(CurrentServerNodeSettingsWildflyImpl.java:41)

I have found the same issue on jboss forum https://developer.jboss.org/message/971717#971717 , but it was unanswered.

Any suggestions?

Answer 1

This is a dependency problem during startup, ie the server name is set after your @PostConstruct method gets executed. Try to load the server name lazy when it is accessed from the application for the first time.

In Wildfly there is no generic way to enforce the sequence of deployments from the application despite the definition of module dependencies. But this won't help in your case.