linux内核参数

fs.file-max   //系统所有进程所能打开文件句柄的最大数，，系统级的。   man 5 proc
fs.file-nr       //the number of file descriptors allocated since boot    total free allocated file descriptors     最大句柄数    (ulimit -a ; unlimit -n 2048) (当前打开的文件句柄为第一列减去第二列)。
                             参考： 
net.ipv4.tcp_tw_reuse = 1      //重用time-wait的socket
net.ipv4.tcp_tw_recycle = 1    //开启time-wait的socket的快速回收
net.ipv4.tcp_keepalive_intvl = 75   //time between tcp keepalive probe
net.ipv4.tcp_keepalive_probes = 9   //the max number of keepalive probe to send
net.ipv4.tcp_keepalive_time = 7200   //tcp发送keepalive的频率
net.ipv4.tcp_fin_timeout              //The  lifetime  of orphaned FIN_WAIT2 state sockets