在Java中使用JMX读取cassandra矩阵

JVM_OPTS="$JVM_OPTS -Dcom.sun.management.jmxremote.port=<port>"
JVM_OPTS="$JVM_OPTS -Dcom.sun.management.jmxremote.rmi.port=<port>"
JVM_OPTS="$JVM_OPTS -Dcom.sun.management.jmxremote.ssl=false"
JVM_OPTS="$JVM_OPTS -Dcom.sun.management.jmxremote.authenticate=false"

import javax.management.MBeanServerConnection;
import javax.management.ObjectName;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;

public class CassandraJMXReader {
    public static void main(String[] args) throws Exception {
        String host = "<cassandra_host>";
        int port = <jmx_port>;

        JMXServiceURL jmxUrl = new JMXServiceURL("service:jmx:rmi:///jndi/rmi://" + host + ":" + port + "/jmxrmi");
        JMXConnector connector = JMXConnectorFactory.connect(jmxUrl, null);
        MBeanServerConnection connection = connector.getMBeanServerConnection();

        // 读取矩阵相关的信息
        ObjectName matrixObjectName = new ObjectName("org.apache.cassandra.metrics:type=Table,keyspace=<keyspace_name>,scope=<table_name>,name=All");
        String matrixValue = (String) connection.getAttribute(matrixObjectName, "Value");

        System.out.println("Matrix Value: " + matrixValue);

        connector.close();
    }
}