ThreadPoolMetrics.java 文件源码

public static Object getJmxMetric(MBeanServerConnection mbeanServerConn, String jmxPath, String poolName, String metricName)
{
    String name = String.format("org.apache.cassandra.metrics:type=ThreadPools,path=%s,scope=%s,name=%s", jmxPath, poolName, metricName);

    try
    {
        ObjectName oName = new ObjectName(name);
        if (!mbeanServerConn.isRegistered(oName))
        {
            return "N/A";
        }

        switch (metricName)
        {
            case "ActiveTasks":
            case "PendingTasks":
            case "CompletedTasks":
                return JMX.newMBeanProxy(mbeanServerConn, oName, JmxReporter.JmxGaugeMBean.class).getValue();
            case "TotalBlockedTasks":
            case "CurrentlyBlockedTasks":
                return JMX.newMBeanProxy(mbeanServerConn, oName, JmxReporter.JmxCounterMBean.class).getCount();
            default:
                throw new AssertionError("Unknown metric name " + metricName);
        }
    }
    catch (Exception e)
    {
        throw new RuntimeException("Error reading: " + name, e);
    }
}