emq系统调优支持更大并发
Linux 操作系统参数
系统全局允许分配的最大文件句柄数:
# 2 millions system-wide
sysctl -w fs.file-max=2097152
sysctl -w fs.nr_open=2097152
echo 2097152 > /proc/sys/fs/nr_open
允许当前会话 / 进程打开文件句柄数:
ulimit -n 1048576
/etc/sysctl.conf
持久化 ‘fs.file-max’ 设置到 /etc/sysctl.conf 文件:
fs.file-max = 1048576
/etc/systemd/system.conf 设置服务最大文件句柄数:
DefaultLimitNOFILE=1048576
/etc/security/limits.conf
/etc/security/limits.conf 持久化设置允许用户 / 进程打开文件句柄数:
* soft nofile 1048576
* hard nofile 1048576
TCP 协议栈网络参数
并发连接 backlog 设置:
sysctl -w net.core.somaxconn=32768
sysctl -w net.ipv4.tcp_max_syn_backlog=16384
sysctl -w net.core.netdev_max_backlog=16384
可用知名端口范围:
sysctl -w net.ipv4.ip_local_port_range='1000 65535'
TCP Socket 读写 Buffer 设置:
sysctl -w net.core.rmem_default=262144
sysctl -w net.core.wmem_default=262144
sysctl -w net.core.rmem_max=16777216
sysctl -w net.core.wmem_max=16777216
sysctl -w net.core.optmem_max=16777216#sysctl -w net.ipv4.tcp_mem='16777216 16777216 16777216'
sysctl -w net.ipv4.tcp_rmem='1024 4096 16777216'
sysctl -w net.ipv4.tcp_wmem='1024 4096 16777216'TCP 连接追踪设置:
sysctl -w net.nf_conntrack_max=1000000
sysctl -w net.netfilter.nf_conntrack_max=1000000
sysctl -w net.netfilter.nf_conntrack_tcp_timeout_time_wait=30
TIME-WAIT Socket 最大数量、回收与重用设置:
sysctl -w net.ipv4.tcp_max_tw_buckets=1048576# 注意：不建议开启該设置，NAT 模式下可能引起连接 RST
# sysctl -w net.ipv4.tcp_tw_recycle=1
# sysctl -w net.ipv4.tcp_tw_reuse=1
FIN-WAIT-2 Socket 超时设置:
sysctl -w net.ipv4.tcp_fin_timeout=15
Erlang 虚拟机参数
优化设置 Erlang 虚拟机启动参数，配置文件 emqx/etc/emqx.conf:
## Erlang Process Limit
node.process_limit = 2097152## Sets the maximum number of simultaneously existing ports for this system
node.max_ports = 1048576
EMQ X 消息服务器参数
设置 TCP 监听器的 Acceptor 池大小，最大允许连接数。配置文件 emqx/etc/emqx.conf:
## TCP Listener
listener.tcp.external = 0.0.0.0:1883
listener.tcp.external.acceptors = 64
listener.tcp.external.max_connections = 1024000
客户端-----测试客户端设置
测试客户端服务器在一个接口上，最多只能创建 65000 连接:
sysctl -w net.ipv4.ip_local_port_range="500 65535"
echo 1000000 > /proc/sys/fs/nr_open
ulimit -n 100000
emqtt_bench
并发连接测试工具: http://github.com/emqx/emqtt_bench
参考链接:
https://docs.emqx.cn/enterprise/v4.3/tutorial/tune.html#emq-x-%E6%B6%88%E6%81%AF%E6%9C%8D%E5%8A%A1%E5%99%A8%E5%8F%82%E6%95%B0
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