测试调优¶
EMQ X 企业版R2版本MQTT连接压力测试到100万，在一台8核心、32G内存的 CentOS 服务器上。
100万连接测试所需的Linux内核参数，网络协议栈参数，Erlang 虚拟机参数，EMQ X 参数设置如下:
Linux内核参数¶
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/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:
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
# net.ipv4.tcp_tw_recycle = 1
# net.ipv4.tcp_tw_reuse = 1
FIN-WAIT-2 Socket超时设置:
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 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etc/emqx.conf:
## TCP Listener
listener.tcp.external= 1883
listener.tcp.external.acceptors = 64
listener.tcp.external.max_connections = 1000000
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
mqtt-jmeter¶
MQTT模拟测试工具: https://github.com/emqtt/mqtt-jmeter