java – Timer正在创建多个计时器实例

我每隔5分钟就开始运行一次.代码看起来像这样：

@Singleton
@TransactionAttribute(TransactionAttributeType.NOT_SUPPORTED)
public class Scheduler {
    private static final double timerVar = Math.random() * 33;

    static Logger logger = Logger.getLogger("Scheduler");

    @Schedule(second = "*",minute = "*/5",hour = "*",persistent = true)
    public void doWork() {
        logger.log(Level.INFO,"timer value for this session : " + timerVar);
    } 
}

当进程运行时,它在1秒的间隙内同时执行10个调度程序实例,即

(EJB default - 1)
(EJB default - 2)
(EJB default - 3)
(EJB default - 4)

等等.当我在代码中放置一个冗长的操作时,(EJB default – 1)不完整,当(EJB default – 2)尝试执行时,它给出了一个错误说：

JBAS014373: EJB 3.1 PFD2 4.8.5.5.1 concurrent access timeout on org.jboss.invocation.InterceptorContext$Invocation@1b83ad52 – could not obtain lock within 5000 MILLISECONDS

首先,如何避免一次执行多个EJB调度程序实例？
第二,什么是“无法在5000MILLISECONDS内获得锁定”的交易,我该如何避免呢？

对于我得到的超时错误,我发现JBOSS队列中有很多票据,如here所述.

编辑

在最新评论中添加了代码,因此它是可读的：

@Tushar-46835,could you expound upon your solution,maybe show us the snippet of what you did? – rtcarlson Oct 2 ’14 at 20:12

@rtcarlson : Here is the code snippet which fixed my issues:

@Resource 
 TimerService timerService; 

 @Schedule(persistent = false,minute = "/30",hour = "") 
 public void checkQueueState() { 
     dt    = new DataAccessFactory(); 
     excvo = dt.canExecute(); 
     dt    = null; 
     available = excvo.isExecuteReady(); 
     if (available) { 
         timerService.createSingleActionTimer(new Date(),new TimerConfig(null,false)); 
     } 
 } 

 @Timeout 
 private void generateReport(Timer timer) {
     logger.info("!!--timeout invoked here " + new Date()); 
 }