线程池监控

小咪咪 2023-02-11 15:30 23阅读 0赞

### 目录 ###

*  实现线程池监控
 *   *  线程池方法
     *  核心监控数
     *  demo
     *  线程池动态修改参数
 *  参考博客

# 实现线程池监控 #

## 线程池方法 ##

**ThreadPoolExecutor**

<table> 
 <thead> 
  <tr> 
   <th>方法名</th> 
   <th>作用</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>beforeExecute</td> 
   <td>提交线程池之前做的操作</td> 
  </tr> 
  <tr> 
   <td>afterExecute</td> 
   <td>线程池执行之后做的操作</td> 
  </tr> 
  <tr> 
   <td>terminated</td> 
   <td>线程池停止前做的操作</td> 
  </tr> 
 </tbody> 
</table>

有可能监控的地方是在提交前跟提交后，这时可以看线程池里面的核心数据。terminated其实意义不大，因为线程池的优势不就是减少线程创建的时间吗，所以很少去shundown。

## 核心监控数 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zODMzNjY1OA_size_16_color_FFFFFF_t_70]

## demo ##

import java.util.concurrent.*;
    
    public class MonitorThreadPoolExecutorDemo { 
    
        public static void main(String[] args) throws InterruptedException, ExecutionException { 
            Thread.sleep(1000L);
            // 方便测试
            ExecutorService executor = new MonitorThreadPoolExecutor(5, 5, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue());
            for (int i = 0; i < 50; i++) { 
                Runnable runnable = () -> { 
                    try { 
                        Thread.sleep(100L);
                    } catch (InterruptedException e) { 
                        e.printStackTrace();
                    }
                };
                executor.execute(runnable);
            }
            executor.shutdown();
            System.out.println("Thread Main End!");
        }
    
    }
    
    class MonitorThreadPoolExecutor extends ThreadPoolExecutor { 
    
        public MonitorThreadPoolExecutor(int arg0, int arg1, long arg2, TimeUnit arg3, BlockingQueue<Runnable> arg4) { 
            super(arg0, arg1, arg2, arg3, arg4);
        }
    
        @Override
        protected void beforeExecute(Thread paramThread, Runnable paramRunnable) { 
            System.out.println("work_task before:" + paramThread.getName());
    
        }
    
        @Override
        protected void afterExecute(Runnable r, Throwable t) { 
            super.afterExecute(r, t);
            System.out.println("work_task after worker thread is :" + r);
            System.out.println("terminated getCorePoolSize:" + this.getCorePoolSize() + "；getPoolSize:" + this.getPoolSize() + "；getTaskCount:" + this.getTaskCount() + "；getCompletedTaskCount:"
                    + this.getCompletedTaskCount() + "；getLargestPoolSize:" + this.getLargestPoolSize() + "；getActiveCount:" + this.getActiveCount());
        }
    
        @Override
        protected void terminated() { 
            /*System.out.println("terminated getCorePoolSize:" + this.getCorePoolSize() + "；getPoolSize:" + this.getPoolSize() + "；getTaskCount:" + this.getTaskCount() + "；getCompletedTaskCount:" + this.getCompletedTaskCount() + "；getLargestPoolSize:" + this.getLargestPoolSize() + "；getActiveCount:" + this.getActiveCount()); System.out.println("ThreadPoolExecutor terminated:");*/
        }
    
    }

**或者**

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zODMzNjY1OA_size_16_color_FFFFFF_t_70 1]

## 线程池动态修改参数 ##

![在这里插入图片描述][20200524113957634.png]  
我们可以通过分布式配置中心进行调整线程池大小。注意：核心线程数>=最大线程池数

# 参考博客 #

*  [Java线程池的监控][Java]
 *  [线程池的参数动态调整][Link 1]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zODMzNjY1OA_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200524111714166.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zODMzNjY1OA==,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zODMzNjY1OA_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20200524112647452.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zODMzNjY1OA==,size_16,color_FFFFFF,t_70
[20200524113957634.png]: https://img-blog.csdnimg.cn/20200524113957634.png
[Java]: http://ifeve.com/java-concurrency-thread-pool-monitor/
[Link 1]: https://www.cnblogs.com/root429/p/12799234.html