代码

//dubbo 线程池数量监控
                Class<?> clazz = Class.forName("com.alibaba.dubbo.rpc.protocol.dubbo.status.ThreadPoolStatusChecker");
                Method check = clazz.getMethod("check");
                Object result = check.invoke(clazz.newInstance());
                logger.info(JSONObject.toJSONString(result));

原理
1. 获取 dubbo 提供的类的对象
2. 读数据即可

dubbo 提供的类

/**
 * ThreadPoolStatusChecker
 */
@Activate
public class ThreadPoolStatusChecker implements StatusChecker {

    @Override
    public Status check() {DataStore dataStore = ExtensionLoader.getExtensionLoader(DataStore.class).getDefaultExtension();
        Map<String, Object> executors = dataStore.get(Constants.EXECUTOR_SERVICE_COMPONENT_KEY);

        StringBuilder msg = new StringBuilder();
        Status.Level level = Status.Level.OK;
        for (Map.Entry<String, Object> entry : executors.entrySet()) {String port = entry.getKey();
            ExecutorService executor = (ExecutorService) entry.getValue();

            if (executor != null && executor instanceof ThreadPoolExecutor) { // 校验是否是线程池
                ThreadPoolExecutor tp = (ThreadPoolExecutor) executor;
                boolean ok = tp.getActiveCount() < tp.getMaximumPoolSize() - 1;
                Status.Level lvl = Status.Level.OK;
                if (!ok) {
                    level = Status.Level.WARN;
                    lvl = Status.Level.WARN;
                }

                if (msg.length() > 0) {msg.append(";");
                }
                msg.append("Pool status:" + lvl
                        + ", max:" + tp.getMaximumPoolSize()
                        + ", core:" + tp.getCorePoolSize()
                        + ", largest:" + tp.getLargestPoolSize()
                        + ", active:" + tp.getActiveCount()
                        + ", task:" + tp.getTaskCount()
                        + ", service port:" + port);
            }
        }
        return msg.length() == 0 ? new Status(Status.Level.UNKNOWN) : new Status(level, msg.toString());
    }

}

字段阐明

测试数据

2020-07-09 17:27:02.893|INFO |dlct2FhXhVFR-39-81|xxx.common.filter.dubbo.AccessLogExtFilter.invoke:175||
{"level":"OK",
"message":"Pool status:OK, // 线程池状态：失常
max:500, // 最大数量
core:500, //core 数量
largest:51, // 线程池线程数量的峰值，线程池中已经有过的最大线程数量
active:1, // 沉闷数量，始终在变动
task:51, // 总任务数量 = 已实现工作数量 + 未实现工作数量
service port: 12029"}

dubbo 源码 -ThreadPoolStatusChecker

msg.append("Pool status:" + lvl
                        + ", max:" + tp.getMaximumPoolSize()
                        + ", core:" + tp.getCorePoolSize()
                        + ", largest:" + tp.getLargestPoolSize()
                        + ", active:" + tp.getActiveCount()
                        + ", task:" + tp.getTaskCount()
                        + ", service port:" + port);

jdk 源码 -ThreadPoolExecutor

1、getLargestPoolSize
largest:51, // 线程池线程数量的峰值，线程池中已经有过的最大线程数量

/**
     * Returns the largest number of threads that have ever
     * simultaneously been in the pool.
     *
     * @return the number of threads
     */
    public int getLargestPoolSize() {
        final ReentrantLock mainLock = this.mainLock;
        mainLock.lock();
        try {return largestPoolSize;} finally {mainLock.unlock();
        }
    }

2、getTaskCount
总的工作数量 = 已实现工作数量 + 工作汇合里未实现工作数量

/**
     * Counter for completed tasks. Updated only on termination of
     * worker threads. Accessed only under mainLock.
     */
    private long completedTaskCount; // 已实现工作数量
    
/**
     * Returns the approximate total number of tasks that have ever been
     * scheduled for execution. Because the states of tasks and
     * threads may change dynamically during computation, the returned
     * value is only an approximation.
     *
     * @return the number of tasks
     */
    public long getTaskCount() {
        final ReentrantLock mainLock = this.mainLock;
        mainLock.lock();
        try {
            long n = completedTaskCount;
            for (Worker w : workers) {
                n += w.completedTasks;
                if (w.isLocked())
                    ++n;
            }
            return n + workQueue.size(); // 已实现工作数量 + 工作汇合里未实现工作数量} finally {mainLock.unlock();
        }
    }

官网 api 解释

long    getTaskCount()
          返回曾打算执行的近似工作总数。

https://doc.yonyoucloud.com/d…