tsung并发数量提不上去，怎么解决？

<?xml version="1.0"?>
<!DOCTYPE tsung SYSTEM "/usr/local/tsung/share/tsung/tsung-1.0.dtd">



<!---->

<servers>
    <server host="127.1.1.1" port="1883" type="tcp" />
</servers>

<load>
    <user session="mqtt_subscriber" start_time="10" unit="second"></user>
    <arrivalphase phase="1" duration="5" unit="minute">
        <users maxnumber="5000" interarrival="0.01" unit="second"/>
    </arrivalphase>
</load>

<sessions>
    <session name="mqtt_publisher" probability="100" type="ts_mqtt">
        <request>
            <mqtt type="connect" clean_start="true" keepalive="10" will_topic="phihome/test" will_qos="1" will_msg="will_msg" will_retain="false"></mqtt>
        </request>

        <for from="1" to="100" incr="1" var="loops">
            <request subst="true">
                <mqtt type="publish" topic="phihome/test" qos="1" retained="true">topic_JKCEBJKQCHEHJQajhcsajhcqh1312312312cacasbkca</mqtt>
            </request>
        </for>

        <request>
            <mqtt type="disconnect"></mqtt>
        </request>
    </session>
    <session name="mqtt_subscriber" probability="0" type="ts_mqtt">
        <request>
            <mqtt type="connect" clean_start="true" keepalive="10"></mqtt>
        </request>

        <request subst="true">
            <mqtt type="subscribe" topic="phihome/test" qos="1"></mqtt>
        </request>

        <request>
            <!-- wait for 60s -->
            <mqtt type="waitForMessages" timeout="60"></mqtt>
        </request>

        <request subst="true">
            <mqtt type="unsubscribe" topic="phihome/test"></mqtt>
        </request>

        <request>
            <mqtt type="disconnect"></mqtt>
        </request>
    </session>
</sessions>

文件句柄：ulimit -n 600000

创建10000个用户， 并发数量一直低于200

这个要考虑你本身服务器的性能存在问题，比如说网络、io、cpu，监测下。