Websphere IBM MQ连接泄漏致线程阻塞问题排查求助

问题背景 #

• 已配置WAS JMS池连接超时为5秒，读取JMS消息时通过finally块关闭连接，但连接未按超时设置释放，出现泄漏
• 无其他应用错误日志，仅通过指定跟踪字符串捕获到连接堆栈信息

使用的WAS跟踪字符串 #

=info: JMSApi=all: JMSServer=all: Messaging=all: JMS_WASTraceAdapter=all: com.ibm.mq.*=all: jmsApi=all: ConnLeakLogic=all: com.ibm.ejs.j2c.*=all

连接泄漏跟踪日志 #

Connection marked to be destroyed. Waiting for transaction end and connection close - MCWrapper id 53b353b3 Managed connection com.ibm.ejs.jms.JMSManagedQueueConnection@29422942
        managed connection factory = com.ibm.ejs.jms.WMQJMSRAManagedConnectionFactory@70a470a4
        physical connection = com.ibm.mq.jms.MQXAQueueConnection@44504450
        connectorName = JMS$MIUFACTORY$JMSManagedConnection@11
        credential = null
        open connection handles = [com.ibm.ejs.jms.JMSQueueConnectionHandle@655a655a] State:STATE_ACTIVE_INUSE Thread Id: 0000005f Thread Name: WebContainer : 5 Handle count 1 Start time inuse Wed Jan 18 16:00:18 GMT 2023 Time inuse 1479 (seconds)
    Connection marked to be destroyed. Waiting for transaction end and connection close - MCWrapper id 270b270b Managed connection com.ibm.ejs.jms.JMSManagedQueueConnection@1c921c92
        managed connection factory = com.ibm.ejs.jms.WMQJMSRAManagedConnectionFactory@70a470a4
        physical connection = com.ibm.mq.jms.MQXAQueueConnection@3c933c93
        connectorName = JMS$MIUFACTORY$JMSManagedConnection@7
        credential = null
        open connection handles = [com.ibm.ejs.jms.JMSQueueConnectionHandle@1c2f1c2f] State:STATE_ACTIVE_INUSE Thread Id: 00000035 Thread Name: WebContainer : 2 Handle count 1 Start time inuse Wed Jan 18 15:24:28 GMT 2023 Time inuse 3629 (seconds)
  Total number of connection in unshared pool: 2 Connection Leak Logic Information:
  MCWrapper id 53b353b3 Managed connection com.ibm.ejs.jms.JMSManagedQueueConnection@29422942
        managed connection factory = com.ibm.ejs.jms.WMQJMSRAManagedConnectionFactory@70a470a4
        physical connection = com.ibm.mq.jms.MQXAQueueConnection@44504450
        connectorName = JMS$MIUFACTORY$JMSManagedConnection@11
        credential = null
        open connection handles = [com.ibm.ejs.jms.JMSQueueConnectionHandle@655a655a] State:STATE_ACTIVE_INUSE Thread Id: 0000005f Thread Name: WebContainer : 5 Handle count 1
     Start time inuse Wed Jan 18 16:00:18 GMT 2023 Time inuse 1479 (seconds)
     Last allocation time Wed Jan 18 16:00:18 GMT 2023
       getConnection stack trace information:
          com.ibm.ejs.j2c.ConnectionManager.allocateConnection(ConnectionManager.java:900)
          com.ibm.ejs.jms.JMSQueueConnectionFactoryHandle.createQueueConnection(JMSQueueConnectionFactoryHandle.java:84)

环境版本信息 #

• WebSphere版本：7.0.0.45
• MQ资源适配器版本：
  • Implementation-Title: WebSphere MQ Resource Adapter
  • Implementation-Version: 7.0.1.14

补充分析：类加载异常 #

经排查，连接泄漏由类加载失败触发，相关jar包已包含在EAR中，但出现ClassNotFoundException，堆栈如下：

java.net.URLClassLoader.findClass(URLClassLoader.java:457): 
at com.ibm.ws.bootstrap.ExtClassLoader.findClass(ExtClassLoader.java:201):  
at java.lang.ClassLoader.loadClass(ClassLoader.java:676):   
at com.ibm.ws.bootstrap.ExtClassLoader.loadClass(ExtClassLoader.java:112):  
at java.lang.ClassLoader.loadClass(ClassLoader.java:642):   
at com.ibm.ws.classloader.ProtectionClassLoader.loadClass(ProtectionClassLoader.java:62):   
at com.ibm.ws.classloader.ProtectionClassLoader.loadClass(ProtectionClassLoader.java:58):   
at com.ibm.ws.classloader.CompoundClassLoader.loadClass(CompoundClassLoader.java:545):  
at java.lang.ClassLoader.loadClass(ClassLoader.java:642):   
at com.ibm.ws.classloader.CompoundClassLoader.loadClass(CompoundClassLoader.java:513):  
at java.lang.ClassLoader.loadClass(ClassLoader.java:642):   
at com.ibm.ws.classloader.CompoundClassLoader.loadClass(CompoundClassLoader.java:545):  
at java.lang.ClassLoader.loadClass(ClassLoader.java:642):   
at 

排查与解决方案建议 #

类加载问题修复 #

1. 验证jar包完整性：检查EAR中对应的jar包是否损坏，重新打包替换，确保目标类文件存在于jar内
2. 调整类加载策略：在WebSphere控制台中，将应用的类加载策略设置为PARENT_LAST，避免父类加载器优先加载导致找不到自定义类
3. 确认jar包位置：确保jar包放置在EAR的APP-INF/lib目录（多模块应用场景），而非单个模块的WEB-INF/lib，保证应用类加载器可访问
4. 排查类冲突：检查WebSphere全局库（如lib/ext目录）是否存在同名类，避免加载错误版本的类

连接泄漏问题解决 #

1. 优先修复类加载异常：类加载失败会导致finally块无法正常执行，进而无法关闭连接，解决ClassNotFoundException是核心前提
2. 增强连接关闭逻辑：在捕获Throwable的代码块中执行连接关闭操作，确保即使出现Error（如类加载错误）也能释放连接：

   Connection conn = null;
   try {
       // 获取连接并处理JMS消息逻辑
   } catch (Exception e) {
       // 异常处理逻辑
   } finally {
       if (conn != null) {
           try {
               conn.close();
           } catch (Exception ce) {
               // 记录连接关闭异常日志
           }
       }
   }
   

3. 检查事务状态：日志显示连接在等待事务结束，通过WebSphere事务监控查看是否存在未提交/回滚的全局事务，及时清理挂起事务
4. 升级版本补丁：WebSphere 7.0.0.45存在已知的JMS连接池泄漏问题，可升级至更高Fix Pack（如7.0.0.47及以上），同时升级MQ资源适配器到兼容版本

内容的提问来源于stack exchange，提问作者Harshal Patil