服务器频繁fullGC，求调优办法

[wedsy120]

服务器一直报CPU饥饿，经过查看GC日志发现系统频繁出现full GC，求教各位大大，如何进行调优？
服务器配置： 8C48G
jvm参数：-Xss1m -Xgcpolicy:optavgpause -Xmns256m -Xmnx512m -Xjit:codetotal=131072 -Xgcthreads2 -Xloamaximum0.2 -Xverbosegclog:${SERVER_LOG_ROOT}/verbosegc.log,20,50000 -Ddefault.client.encoding=UTF-8 -Dfile.encoding=UTF-8 -Duser.language=Zh -Duser.region=UTF-8
最大堆大小设置：16G 初始堆大小：8G
附一段GC日志如下：
<con event="completed full sweep" timestamp="Jul 21 09:39:56 2015">
<stats sweepbytes="0" sweeptime="0.137" connectbytes="1071644672" connecttime="0.404" />
</con>
<con event="final card cleaning">
<stats cardscleaned="246365" traced="214280148" durationms="961.201" />
</con>
<gc type="global" id="6791" totalid="6791" intervalms="144892.522">
<finalization objectsqueued="419" />
<timesms mark="359.271" sweep="0.182" compact="0.000" total="360.584" />
<tenured freebytes="1661855104" totalbytes="17177772032" percent="9" >
<soa freebytes="1661855104" totalbytes="17177772032" percent="9" />
<loa freebytes="0" totalbytes="0" percent="0" />
</tenured>
</gc>
<tenured freebytes="1661855104" totalbytes="17177772032" percent="9" >
<soa freebytes="1661855104" totalbytes="17177772032" percent="9" />
<loa freebytes="0" totalbytes="0" percent="0" />
</tenured>
<refs soft="5194" weak="570816" phantom="2117" dynamicSoftReferenceThreshold="3" maxSoftReferenceThreshold="32" />
<time totalms="1323.670" />
</con>

<con event="completed sweep" timestamp="Jul 21 09:39:57 2015">
<stats bytes="0" time="0.002" />
</con>

<con event="kickoff" timestamp="Jul 21 09:39:57 2015">
<kickoff reason="Kickoff threshold reached" />
<stats tenurefreebytes="753834800" tracetarget="10256393073" kickoff="1392678656" />
</con>

[呵呵一笑哈]

其实我比较想知道你们的服务器负荷多少，为啥不再开个服务器分摊请求？如果请求少的话，先不说服务器设置怎么样，代码里该销毁的对象设成null了么？

[不断学习的ITer]

full GC 说明对象占用内存没有释放，导致新对象申请内存出现内存不足的情况，系统强制GC。检查代码。