与Socket.io和Docker无法获得超过980个连接
我无法扩展我的简单的Socket.IO应用程序过去使用Docker的980个并发连接。 但是，如果我在macOS Sierra 10.12.6本地运行它，我可以获得超过3000个连接。 我已经包含了我正在testing的一个简单的SocketIO应用程序的回购： https ： //github.com/gsccheng/simple-socketIO-app
我的Docker-for-Macconfiguration为4个CPU和5GB内存。 版本是
Version 17.09.0-ce-mac35 (19611) Channel: stable a98b7c1b7c 我正在使用炮兵版本1.6.0-9加载testing
$ artillery run load-test.yaml
我正在显示一些设置的冗余configuration（以显示它们已被考虑）。 这是我的重现步骤。
$ docker build . -t socket-test $ docker run -p 8000:8000 -c 1024 -m 4096M --privileged --ulimit nofile=9000:9000 -it test-socket:latest /bin/sh #> DEBUG=* npm start
高达约980个连接，我会得到像这样的日志：
Connected to Socket! socket.io:client writing packet {"type":2,"data":["news",{"hello":"world"}],"nsp":"/"} +0ms socket.io-parser encoding packet {"type":2,"data":["news",{"hello":"world"}],"nsp":"/"} +0ms socket.io-parser encoded {"type":2,"data":["news",{"hello":"world"}],"nsp":"/"} as 2["news",{"hello":"world"}] +0ms engine:socket sending packet "message" (2["news",{"hello":"world"}]) +0ms socket.io:socket joined room 0ohCcHMWYASnfRgJAAPS +0ms engine:ws received "2" +5ms engine:socket packet +0ms engine:socket got ping +0ms engine:socket sending packet "pong" (undefined) +0ms engine:socket flushing buffer to transport +0ms engine:ws writing "3" +0ms engine upgrading existing transport +2ms engine:socket might upgrade socket transport from "polling" to "websocket" +0ms engine intercepting request for path "/socket.io/" +2ms engine handling "GET" http request "/socket.io/?EIO=3&transport=polling&t=Ly8pfqL&b64=1&sid=0ohCcHMWYASnfRgJAAPS" +0ms engine setting new request for existing client +0ms engine:polling setting request +0ms engine:socket flushing buffer to transport +0ms engine:polling writing "28:42["news",{"hello":"world"}]" +0ms engine:socket executing batch send callback +1ms engine:ws received "2probe" +4ms engine:ws writing "3probe" +0ms engine intercepting request for path "/socket.io/" +4ms engine handling "GET" http request "/socket.io/?EIO=3&transport=polling&t=Ly8pfqV&b64=1&sid=0ohCcHMWYASnfRgJAAPS" +0ms engine setting new request for existing client +0ms engine:polling setting request +0ms engine:socket writing a noop packet to polling for fast upgrade +10ms engine:polling writing "1:6" +0ms engine:ws received "5" +2ms engine:socket got upgrade packet - upgrading +0ms engine:polling closing +0ms engine:polling transport discarded - closing right away +1ms engine:ws received "2" +20ms engine:socket packet +0ms engine:socket got ping +0ms engine:socket sending packet "pong" (undefined) +0ms engine:socket flushing buffer to transport +1ms engine:ws writing "3" +0ms engine intercepting request for path "/socket.io/" +1ms engine handling "GET" http request "/socket.io/?EIO=3&transport=polling&t=Ly8pfr1&b64=1" +0ms engine handshaking client "6ccAiZwbvrchxZEiAAPT" +0ms engine:socket sending packet "open" ({"sid":"6ccAiZwbvrchxZEiAAPT","upgrades":["websocket"],"pingInterval":25000,"pingTimeout":60000}) +0ms engine:socket sending packet "message" (0) +0ms engine:polling setting request +0ms engine:socket flushing buffer to transport +0ms engine:polling writing "97:0{"sid":"6ccAiZwbvrchxZEiAAPT","upgrades":["websocket"],"pingInterval":25000,"pingTimeout":60000}2:40" +0ms engine:socket executing batch send callback +0ms socket.io:server incoming connection with id 6ccAiZwbvrchxZEiAAPT +0ms socket.io:client connecting to namespace / +1ms socket.io:namespace adding socket to nsp / +0ms socket.io:socket socket connected - writing packet +0ms socket.io:socket joining room 6ccAiZwbvrchxZEiAAPT +0ms socket.io:socket packet already sent in initial handshake +0ms Connected to Socket!
在大约980个连接处，我将开始看到这些不连贯的事件：
disconnected to Socket! transport close engine intercepting request for path "/socket.io/" +27ms engine handling "GET" http request "/socket.io/?EIO=3&transport=polling&t=Ly8pg1T&b64=1" +0ms engine handshaking client "C-pdSXFCbwQaTeYLAAPh" +0ms engine:socket sending packet "open" ({"sid":"C-pdSXFCbwQaTeYLAAPh","upgrades":["websocket"],"pingInterval":25000,"pingTimeout":60000}) +0ms engine:socket sending packet "message" (0) +0ms engine:polling setting request +0ms engine:socket flushing buffer to transport +0ms engine:polling writing "97:0{"sid":"C-pdSXFCbwQaTeYLAAPh","upgrades":["websocket"],"pingInterval":25000,"pingTimeout":60000}2:40" +0ms engine:socket executing batch send callback +0ms socket.io:server incoming connection with id C-pdSXFCbwQaTeYLAAPh +0ms socket.io:client connecting to namespace / +0ms socket.io:namespace adding socket to nsp / +0ms socket.io:socket socket connected - writing packet +1ms socket.io:socket joining room C-pdSXFCbwQaTeYLAAPh +0ms socket.io:socket packet already sent in initial handshake +0ms Connected to Socket! socket.io:client writing packet {"type":2,"data":["news",{"hello":"world"}],"nsp":"/"} +0ms socket.io-parser encoding packet {"type":2,"data":["news",{"hello":"world"}],"nsp":"/"} +0ms socket.io-parser encoded {"type":2,"data":["news",{"hello":"world"}],"nsp":"/"} as 2["news",{"hello":"world"}] +0ms engine:socket sending packet "message" (2["news",{"hello":"world"}]) +0ms socket.io:socket joined room C-pdSXFCbwQaTeYLAAPh +0ms engine intercepting request for path "/socket.io/" +13ms engine handling "POST" http request "/socket.io/?EIO=3&transport=polling&t=Ly8pg1g&b64=1&sid=C-pdSXFCbwQaTeYLAAPh" +0ms engine setting new request for existing client +1ms engine:polling received "1:1" +0ms engine:polling got xhr close packet +0ms socket.io:client client close with reason transport close +0ms socket.io:socket closing socket - reason transport close +1ms disconnected to Socket!
那么它会一遍又一遍地重复：
engine:ws writing "3" +0ms engine:ws received "2" +42ms engine:socket packet +0ms engine:socket got ping +0ms engine:socket sending packet "pong" (undefined) +1ms engine:socket flushing buffer to transport +0ms engine:ws writing "3" +0ms engine:ws received "2" +4ms engine:socket packet +0ms engine:socket got ping +0ms engine:socket sending packet "pong" (undefined) +0ms engine:socket flushing buffer to transport +0ms engine:ws writing "3" +0ms engine:ws received "2" +45ms engine:socket packet +0ms engine:socket got ping +0ms engine:socket sending packet "pong" (undefined) +0ms engine:socket flushing buffer to transport +0ms engine:ws writing "3" +0ms engine:ws received "2" +7ms engine:socket packet +0ms engine:socket got ping +0ms engine:socket sending packet "pong" (undefined) +0ms engine:socket flushing buffer to transport +0ms engine:ws writing "3" +0ms
正如你可以在我的Dockerfile中看到的，我已经设置了一些从Googlesearch问题中收集的configuration：
COPY limits.conf /etc/security/ COPY sysctl.conf /etc/ COPY rc.local /etc/ COPY common-session /etc/pam.d/ COPY common-session-noninteractive /etc/pam.d/ COPY supervisord.conf /etc/supervisor/
在我的本地系统上，我也做了一些configuration，如下面的例子 。 这是我的主机的状态：
$ ulimit -a core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited file size (blocks, -f) unlimited max locked memory (kbytes, -l) unlimited max memory size (kbytes, -m) unlimited open files (-n) 64000 pipe size (512 bytes, -p) 1 stack size (kbytes, -s) 8192 cpu time (seconds, -t) unlimited max user processes (-u) 2048 virtual memory (kbytes, -v) unlimited
我能做些什么来获得超过〜980个并发套接字连接？ 为什么我不能在这一点上build立更多的联系呢？ 我的回购如何调整（如果需要），以使这个工作？
编辑
当我将容器的nofiles限制降低到500时，我发现我的应用程序断开连接似乎也以同样的方式失败。 当我增加或减less我的内存和CPU的一半/双。 我没有看到任何不同的行为，所以似乎并不是这个问题。
在本地应用程序的path与在Docker for Mac中运行的应用程序之间存在显着差异。
Mac上的应用程序的path是通过回送接口：
mac client -> lo -> nodejs
在使用Docker for Mac时，path中包含更多的跃点，并包含两个用户态代理进程：
mac | vm | container client -> lo -> vpnkit -> if -> docker-proxy -> NAT -> bridge -> if -> nodejs
尝试使用可以直接访问networking的虚拟机来查看vpnkit是否有显着的vpnkit 。
mac | vm | container client -> if -> if -> docker-proxy -> NAT -> bridge -> if -> nodejs
您也可以通过将容器接口直接附加到VMnetworking来移除docker-proxy ，以便容器不需要端口映射（ -p ）。 这可以通过将macvlan接口映射到容器或将容器放置在连接到VMnetworking的网桥上来完成。 这是一个用于桥接networking的stream浪设置 。
mac | container <- there is a little vm here, but minimal. client -> if -> if -> nodejs mac | vm | container client -> if -> if -> bridge -> if -> nodejs
一旦你摆脱了networking的差异，那么我会考虑更详细地调整虚拟机和容器。 我猜你应该会看到虚拟机下降10-20％，而不是66％。