在WildFly中配置ActiveMQ Artemis自定义负载均衡类遇类找不到异常

问题背景 #

在WildFly（JBoss）中集成ActiveMQ Artemis时，配置了客户端侧自定义连接负载均衡策略，但运行时触发ClassNotFoundException。

核心配置（CLI） #

## Artemis Broker Config
/socket-binding-group=standard-sockets/remote-destination-outbound-socket-binding=remote-artemis1:add(host=my-broker, port=61616)
/subsystem=messaging-activemq/server=default/remote-connector=remote-artemis1:add(socket-binding=remote-artemis1)

## Global Artemis Conf
/subsystem=messaging-activemq/server=default/pooled-connection-factory=remote-artemis:add(entries=["java:/RemoteJmsXA", "java:jboss/RemoteJmsXA"],connectors=["remote-artemis1"], user="###ARTEMIS_USER###", password="###ARTEMIS_USER_PASSWORD###", ha="true", min-pool-size="3", max-pool-size="30", statistics-enabled="true", connection-load-balancing-policy-class-name="online.myproject.utils.amqartemis.RoundRobinFromFirstConnectionLoadBalancingPolicy") <--- 问题所在

/subsystem=naming/binding=java\:global\/remoteContext:add(binding-type=external-context, module="org.apache.activemq.artemis", class="javax.naming.InitialContext", environment=[java.naming.factory.initial="org.apache.activemq.artemis.jndi.ActiveMQInitialContextFactory", java.naming.provider.url="tcp://my-broker:61616", queue.Server_Emit_MyQueue="Server_Emit_MyQueue"])

自定义负载均衡类 #

package online.myproject.utils.amqartemis;

import org.apache.activemq.artemis.api.core.client.loadbalance.ConnectionLoadBalancingPolicy;

import java.io.Serializable;

public class RoundRobinFromFirstConnectionLoadBalancingPolicy implements ConnectionLoadBalancingPolicy, Serializable {

    private int pos = -1;

    @Override
    public int select(final int max) {

        pos++;

        if (pos >= max) {
            pos = 0;
        }
        return pos;
    }
}

报错日志 #

[0m[33m12:18:16,024 WARN  [org.apache.activemq.artemis.ra] (default-threads - 1) AMQ152005: Failure in broker activation org.apache.activemq.artemis.ra.inflow.ActiveMQActivationSpec(ra=org.wildfly.extension.messaging.activemq.ActiveMQResourceAdapter@69686637 destination=java:global/remoteContext/RestServer_Receive_MediaCreation destinationType=javax.jms.Queue selector=messageType='MEDIA_REFERENCE_CREATED_1.0.0' ack=Auto-acknowledge durable=false clientID=null user=null maxSession=15): ActiveMQInternalErrorException[errorType=INTERNAL_ERROR message=AMQ219004: Failed to initialise session factory]
    at org.apache.activemq.artemis@2.10.1//org.apache.activemq.artemis.core.client.impl.ServerLocatorImpl.initialize(ServerLocatorImpl.java:313)
    at org.apache.activemq.artemis@2.10.1//org.apache.activemq.artemis.core.client.impl.ServerLocatorImpl.createSessionFactory(ServerLocatorImpl.java:768)
    at org.apache.activemq.artemis.ra@2.10.1//org.apache.activemq.artemis.ra.inflow.ActiveMQActivation.setup(ActiveMQActivation.java:314)
    at org.apache.activemq.artemis.ra@2.10.1//org.apache.activemq.artemis.ra.inflow.ActiveMQActivation$SetupActivation.run(ActiveMQActivation.java:731)
    at org.wildfly.extension.messaging-activemq//org.wildfly.extension.messaging.activemq.ActiveMQResourceAdapter$WorkWrapper.run(ActiveMQResourceAdapter.java:171)
    at org.jboss.ironjacamar.impl@1.4.17.Final//org.jboss.jca.core.workmanager.WorkWrapper.runWork(WorkWrapper.java:445)
    at org.jboss.as.connector@18.0.1.Final//org.jboss.as.connector.services.workmanager.WildflyWorkWrapper.runWork(WildflyWorkWrapper.java:69)
    at org.jboss.ironjacamar.impl@1.4.17.Final//org.jboss.jca.core.workmanager.WorkWrapper.run(WorkWrapper.java:223)
    at org.jboss.threads@2.3.3.Final//org.jboss.threads.SimpleDirectExecutor.execute(SimpleDirectExecutor.java:29)
    at org.jboss.threads@2.3.3.Final//org.jboss.threads.QueueExecutor.runTask(QueueExecutor.java:789)
    at org.jboss.threads@2.3.3.Final//org.jboss.threads.QueueExecutor.access$100(QueueExecutor.java:44)
    at org.jboss.threads@2.3.3.Final//org.jboss.threads.QueueExecutor$Worker.run(QueueExecutor.java:809)
    at java.base/java.lang.Thread.run(Thread.java:829)
    at org.jboss.threads@2.3.3.Final//org.jboss.threads.JBossThread.run(JBossThread.java:485)
Caused by: java.lang.IllegalStateException: java.lang.ClassNotFoundException: online.myproject.utils.amqartemis.RoundRobinFromFirstConnectionLoadBalancingPolicy from [Module "org.wildfly.extension.messaging-activemq" from local module loader @22f31dec (finder: local module finder @34c01041 (roots: /opt/jboss/wildfly/modules,/opt/jboss/wildfly/modules/system/layers/base))]
    at org.apache.activemq.artemis.journal//org.apache.activemq.artemis.utils.ClassloadingUtil.newInstanceFromClassLoader(ClassloadingUtil.java:59)
    at org.apache.activemq.artemis@2.10.1//org.apache.activemq.artemis.core.client.impl.ServerLocatorImpl$3.run(ServerLocatorImpl.java:281)
    at java.base/java.security.AccessController.doPrivileged(Native Method)
    at org.apache.activemq.artemis@2.10.1//org.apache.activemq.artemis.core.client.impl.ServerLocatorImpl.instantiateLoadBalancingPolicy(ServerLocatorImpl.java:278)
    at org.apache.activemq.artemis@2.10.1//org.apache.activemq.artemis.core.client.impl.ServerLocatorImpl.initialize(ServerLocatorImpl.java:302)
    ... 13 more
Caused by: java.lang.ClassNotFoundException: online.myproject.utils.amqartemis.RoundRobinFromFirstConnectionLoadBalancingPolicy from [Module "org.wildfly.extension.messaging-activemq" from local module loader @22f31dec (finder: local module finder @34c01041 (roots: /opt/jboss/wildfly/modules,/opt/jboss/wildfly/modules/system/layers/base))]
    at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:255)
    at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:410)
    at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:398)
    at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:116)
    at org.apache.activemq.artemis.journal//org.apache.activemq.artemis.utils.ClassloadingUtil.newInstanceFromClassLoader(ClassloadingUtil.java:55)
    ... 17 more

问题根源 #

WildFly采用模块化类加载机制，org.wildfly.extension.messaging-activemq模块默认无法访问你的自定义类，因为该类不在其依赖的模块路径中，因此触发类加载异常。

解决方案 #

方案一：通过连接工厂配置指定模块（推荐） #

无需修改系统模块，直接在CLI配置中为连接工厂添加module属性，指定自定义类所在的模块：

/subsystem=messaging-activemq/server=default/pooled-connection-factory=remote-artemis:add(
    entries=["java:/RemoteJmsXA", "java:jboss/RemoteJmsXA"],
    connectors=["remote-artemis1"],
    user="###ARTEMIS_USER###",
    password="###ARTEMIS_USER_PASSWORD###",
    ha="true",
    min-pool-size="3",
    max-pool-size="30",
    statistics-enabled="true",
    connection-load-balancing-policy-class-name="online.myproject.utils.amqartemis.RoundRobinFromFirstConnectionLoadBalancingPolicy",
    module="online.myproject.utils.amqartemis"
)

然后按以下步骤创建自定义模块：

1. 在WildFly的modules目录下创建路径：modules/online/myproject/utils/amqartemis/main/
2. 将编译好的自定义类打包成jar，放入上述目录
3. 在该目录创建module.xml，内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<module xmlns="urn:jboss:module:1.3" name="online.myproject.utils.amqartemis">
    <resources>
        <!-- 替换为你的自定义类jar包名称 -->
        <resource-root path="custom-amq-loadbalance-policy.jar"/>
    </resources>
    <dependencies>
        <!-- 依赖ActiveMQ Artemis核心API模块 -->
        <module name="org.apache.activemq.artemis"/>
        <!-- 依赖Java基础API模块 -->
        <module name="javax.api"/>
    </dependencies>
</module>

方案二：修改系统模块依赖 #

如果需要让org.wildfly.extension.messaging-activemq模块直接访问自定义类，可以修改其模块依赖：

1. 按方案一的步骤创建自定义模块
2. 编辑modules/system/layers/base/org/wildfly/extension/messaging-activemq/main/module.xml，添加依赖：

<dependencies>
    <!-- 保留原有所有依赖 -->
    <module name="online.myproject.utils.amqartemis"/>
</dependencies>

最后步骤 #

完成配置后，重启WildFly服务器，让模块加载生效。

内容的提问来源于stack exchange，提问作者Theo Cerutti