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Thread Pool Monitoring 2 - Monitor thread pool status, number of threads, number of queued tasks, etc.

Popularity：128 ℃/2024-10-10 12:22:08

1.Realization Principle

This blog post is based onThread Pool Monitoring 1-Monitoring Task Execution TimeThe principle is: to create a fixed time interval execution of the thread to record the thread pool pool state, the number of threads and the number of queue tasks , etc., the specific program: the use of a singleton class to cache all the created thread pool objects , class creation start timed task thread , regularly traversing the thread pool in the cache to record the thread pool information.

2.Realization code 
package ;

import ;
import ;
import ;

/**
 * Global monitoring <br>.
 * 1. Record thread pool basic information periodically <br>
 *
 *@author xkzhangsan
 */
public class GlobalMonitor {
    private static volatile GlobalMonitor instance;
    private static final ConcurrentHashMap<String, ThreadPoolMonitor> threadPoolMonitorMap = new ConcurrentHashMap<>();
    private static final ScheduledThreadPoolExecutor scheduledThreadPoolExecutor = new ScheduledThreadPoolExecutor(1);

    private GlobalMonitor() {
        (new PoolInfoRunnable(), 10, 10, );
    }

    public static GlobalMonitor getInstance() {
        if (instance == null) {
            synchronized (GlobalMonitor.class) {
                if (instance == null) {
                    instance = new GlobalMonitor();
                }
            }
        }
        return instance;
    }

    public void put(String poolName, ThreadPoolMonitor threadPoolMonitor) {
        (poolName, threadPoolMonitor);
    }

    public void remove(String poolName) {
        (poolName);
    }

    static class PoolInfoRunnable implements Runnable {

        @Override
        public void run() {
            ((poolName, threadPoolMonitor) -> {
                int currentPoolSize = ();
                int queueSize = ().size();
                ("poolName:" + poolName + " status:" + () + " corePoolSize:" + () + " maximumPoolSize:"
                        + () + " currentPoolSize:" + currentPoolSize + " queueCapacity:" + ()
                        + " queueSize:" + queueSize);
            });
        }
    }

}

 

Getting Thread Pool Status

The reference here is to ThreadPoolExecutor's toString(), which returns Running, Shutting down, and Terminated.

See:ThreadPoolMonitor class

    public String getStatus() {
        if (super.isTerminated()) {
            return "Terminated";
        } else if (super.isShutdown()) {
            return "Shutting down";
        } else {
            return "Running";
        }
    }

Get the total queue capacity

When creating a ThreadPoolExecutor, the BlockingQueue<Runnable> workQueue, passed in, can't get the total capacity directly, and the ThreadPoolExecutor doesn't have a method to get the total capacity directly.
Here think of another method, Queue's maintainingCapacity () to return the remaining capacity of the current queue, the principle: the total capacity - queue size, so, just created when the size is 0, the return of the total capacity.
See:ThreadPoolMonitor class

    private void init(String poolName, MonitorLevelEnum monitorLevel) {
        this.poolName = poolName;
        this.monitorLevel = monitorLevel;
        this.taskStartTimeMap = new ConcurrentHashMap<>();
        if (isPoolMonitor()) {
            ().put(poolName, this);
        }
         = super.getQueue().remainingCapacity();
    }

    public int getQueueCapacity() {
        return this.queueCapacity;
    }


3. Test Run

3.1 Test code

package ;

import ;

import ;
import ;

public class ThreadPoolMonitorTest {

    public static void main(String[] args) {
        poolMonitor();
    }

    public static void poolMonitor() {
        ThreadPoolMonitor threadPoolMonitor = new ThreadPoolMonitor(1, 3, 0, , new ArrayBlockingQueue<>(1000), "test", );
        for (int i = 0; i < 100; i++) {
            int finalI = i;
            (() -> {
                try {
                    (3);
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
                (finalI);
            });
        }
        ();
    }
}

 

3.2 Test results

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poolName:test status:Shutting down corePoolSize:1 maximumPoolSize:3 currentPoolSize:1 queueCapacity:1000 queueSize:96
3
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5
poolName:test status:Shutting down corePoolSize:1 maximumPoolSize:3 currentPoolSize:1 queueCapacity:1000 queueSize:93
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poolName:test status:Shutting down corePoolSize:1 maximumPoolSize:3 currentPoolSize:1 queueCapacity:1000 queueSize:90
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threadingsleep 3s，Monitoring Logs10sprint once，Tasks in the queue are decreasing。
source code address：/xkzhangsan/thread-pool-monitor


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