Linux参数调优

一、系统参数调优

打开文件 /etc/sysctl.conf

############
# 一般服务器调整  #
############
#最大连接数
net.core.somaxconn = 32768
#内存分配策略 1表示内核允许分配所有的物理内存，而不管当前的内存状态如何
vm.overcommit_memory = 1
#修改消息队列长度
kernel.msgmnb = 65535
kernel.msgmax = 65535
#所能接受SYN同步包的最大客户端数量，即半连接上限
net.ipv4.tcp_max_syn_backlog = 65535
#允许系统打开的端口范围
net.ipv4.ip_local_port_range = 10240 61440
#当keepalive 起用的时候，TCP 发送keepalive 消息的频度。缺省是2小时,单位秒
net.ipv4.tcp_keepalive_time = 1800
#关闭ipv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1

############################################
# 无状态服务器调整 , 可能会使连接丢失 , 比如网页session                       #
# 不适合需要登录的服务器场景 , 但是适合高并发服务器,比如纯redis服务器   #
############################################
#启用timewait 快速回收 , 服务器不要开启
net.ipv4.tcp_tw_recycle = 1
#开启重用 , 允许将TIME-WAIT sockets 重新用于新的TCP 连接 , 服务器不要开启
net.ipv4.tcp_tw_reuse = 1
#CLOSE_WAIT超时时间
net.ipv4.tcp_fin_timeout = 5
#当keepalive 起用的时候，TCP 发送keepalive 消息的频度。缺省是2 小时,单位秒 , 指的是60秒检查一次tcp是否存活
net.ipv4.tcp_keepalive_time = 60

###########参数复制版############
net.core.somaxconn = 32768
vm.overcommit_memory = 1
kernel.msgmnb = 65535
kernel.msgmax = 65535
net.ipv4.ip_local_port_range = 10240 61440
net.ipv4.tcp_keepalive_time = 60
net.ipv4.tcp_tw_recycle = 0
net.ipv4.tcp_tw_reuse = 0
net.ipv4.tcp_fin_timeout = 5
net.ipv4.tcp_max_syn_backlog = 65535
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
##############################

二、使配置生效(不需要重启)

#执行以下命令使配置生效
sysctl -p

#其他参考的例子
net.ipv4.tcp_syncookies = 1
net.ipv4.ip_local_port_range = 32768  61000
net.ipv4.tcp_fin_timeout = 30
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_syn_retries = 1
net.ipv4.tcp_tw_recycle = 0
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_max_tw_buckets = 6000
net.ipv4.tcp_max_orphans = 3276800
net.ipv4.tcp_max_syn_backlog = 262144
net.ipv4.tcp_keepalive_intvl = 30
net.ipv4.tcp_keepalive_probes = 3
net.ipv4.tcp_keepalive_time = 1800
net.ipv4.tcp_keepalive_probes = 5
net.ipv4.tcp_keepalive_intvl = 15
net.core.netdev_max_backlog = 262144
net.core.somaxconn = 65535
vm.overcommit_memory = 1
net.core.rmem_default = 8388608
net.core.wmem_default = 8388608
net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_mem = 94500000   915000000   927000000
net.ipv4.tcp_rmem = 4096   87380   16777216
net.ipv4.tcp_wmem = 4096   16384   16777216
#net.netfilter.nf_conntrack_max=655350
#net.netfilter.nf_conntrack_tcp_timeout_established=1200
net.ipv4.icmp_echo_ignore_broadcasts = 1
net.ipv4.icmp_ignore_bogus_error_responses = 1
kernel.sysrq = 0
kernel.core_uses_pid = 1
kernel.msgmnb = 65536
kernel.msgmax = 65536