【原创】图解hotwheels

2019独角兽企业重金招聘Python工程师标准>>>

项目地址&＃xff1a; tolbrino/hotwheels
项目说明&＃xff1a; Erlang messaging server optimized to send 1 message to 40k subscribers to a topic in <1s

概述

Janus 是一种消息服务器&＃xff0c;专门被优化以便能够处理&＃xff0c;以 TCP 单播方式同时发消息给数以千计客户端的场景。这些客户端可以订阅到各种 topic 上。
终极目标是能够在 20k 客户端同时在线的情况下&＃xff0c;进行消息推送时保证延时低于 2 秒。

关于 Janus 的历史

在罗马神话中 Janus 是天门神&＃xff0c;早晨打开天门&＃xff0c;让阳光普照人间&＃xff0c;晚上又把天门关上&＃xff0c;使黑暗降临大地。他的头部前后各有一副面孔&＃xff0c;同时看着两个不同方向&＃xff0c;一副看着过去&＃xff0c;一副看着未来&＃xff0c;因此也称两面神&＃xff0c;或被尊称为时间之神。罗马有好几座 Janus 神庙。Janus 掌管所有的出入门户&＃xff0c;因此罗马人在战时永远将 Janus 神殿的门敞开着&＃xff0c;以便军人在败阵时躲入殿内以求庇护&＃xff0c;或是在战胜时凯旋入殿。早期的 Janus 神像的两副面孔都有胡子&＃xff0c;后来没有胡子&＃xff0c;但是一副面孔年轻&＃xff0c;另一副面孔年老。Janus 的右手指上刻有数字 CCC&＃xff08;300&＃xff09;&＃xff0c;左手指上刻着数字 LXV&＃xff08;65&＃xff09;&＃xff0c;合在一起恰是一年的天数。从纪元前 1 世纪起&＃xff0c;罗马人把祭祀 Janus 的节日和新年结合在一起。罗马的执政官也在元旦这一天就职&＃xff0c;并向 Janus 献祭&＃xff0c;祈求国家的安宁。为了纪念 Janus&＃xff0c;罗马人把正月称为 Januarius&＃xff08;mensis&＃xff09;&＃xff0c;意含“Janus 之月”&＃xff0c;英文借用了该词&＃xff0c;先作 Januarie&＃xff0c;后作 January 。而在英文吸收 January 一词之前&＃xff0c;撒克逊人把正月叫作 Wulf-Monath&＃xff08;wolf-month&＃xff09;&＃xff0c;意为“狼月”&＃xff0c;因为此时正值严冬&＃xff0c;是狼群出没村子寻觅食物的时节。

关于 hotwheels&＃xff08;即风火轮&＃xff09;的历史

风火轮&＃xff0c;双轮暗藏风火之势&＃xff0c;行动间有风雷之声&＃xff0c;故称风火轮。可踏在脚下作为交通工具&＃xff0c;踏上其轮&＃xff0c;念动咒语&＃xff0c;上天入地&＃xff0c;无所不能。传说是青鸾火凤所化&＃xff0c;一蹬九万里&＃xff0c;双足十八万里。传说中为哪吒兵器之一。

监督树总体结构

|janus_app|| (one_for_one)&＃43;-------------------&＃43;------------------&＃43;--------------------&＃43;| | | || | | |topman janus_acceptor (supervisor) mapper| || | (simple_one_for_one)&＃43;--------&＃43;-------| &＃43;--------&＃43;-------&＃43;| | | | | || | | | | |pubsub ... pubsub ... transport ... (topic:<<"T1">>) (topic:<<"T2">>) || (janus_flash 封装层)|client_proxy 其中
topman - 维护 pubsub 进程和 Topic 的映射关系&＃xff1b;
pubsub - 关联特定 Topic 的进程 &＃xff1b;维护所有订阅到该 Topic 的进程信息&＃xff1b;
janus_acceptor - 处理来自网络的 TCP 连接&＃xff1b;动态创建 transport 和 client_proxy 进程&＃xff0c;以处理后续协议交互&＃xff1b;
transport - 针对某个 TCP 连接上的数据处理&＃xff1b;
client_proxy - 实际处理订阅&＃xff0c;取消订阅&＃xff0c;以及消息推送的模块&＃xff1b;
mapper - 提供轻量级进程注册管理功能&＃xff1b;

subscriber 行为

janus 针对 subscribe 的内部处理

publisher 行为

janus 针对 publish 的内部处理

协议细节

subscriber 协议交互

对应

flashbot janus,0,PING,0---------------------------------------------->{"timestamp":[1448,434925,303633],"token":[55,97,55,100,48,102,56,98,102,97,97,49,54,101,48,48,48,100,101,99,54,55,48,57,55,99,101,99,97,99,56,56]},1<----------------------------------------------,0,{"action":"subscribe","data":"events"},0---------------------------------------------->ACK,1<----------------------------------------------{"timestamp":[1448,434925,395864],"topic":"events","event":"test_event","message_id":"","data":"test"},1<----------------------------------------------,0,{"action":"unsubscribe","data":"events"},0----------------------------------------------> 对应

00000000 3c 72 65 67 75 6c 61 72 2d 73 6f 63 6b 65 74 2f 00000010 3e 00 50 49 4e 47 00 >.PING.00000000 7b 22 74 69 6d 65 73 74 61 6d 70 22 3a 5b 31 34 {"timest amp":[1400000010 34 38 2c 34 33 34 39 32 35 2c 33 30 33 36 33 33 48,43492 5,30363300000020 5d 2c 22 74 6f 6b 65 6e 22 3a 5b 35 35 2c 39 37 ],"token ":[55,9700000030 2c 35 35 2c 31 30 30 2c 34 38 2c 31 30 32 2c 35 ,55,100, 48,102,500000040 36 2c 39 38 2c 31 30 32 2c 39 37 2c 39 37 2c 34 6,98,102 ,97,97,400000050 39 2c 35 34 2c 31 30 31 2c 34 38 2c 34 38 2c 34 9,54,101 ,48,48,400000060 38 2c 31 30 30 2c 31 30 31 2c 39 39 2c 35 34 2c 8,100,10 1,99,54,00000070 35 35 2c 34 38 2c 35 37 2c 35 35 2c 39 39 2c 31 55,48,57 ,55,99,100000080 30 31 2c 39 39 2c 39 37 2c 39 39 2c 35 36 2c 35 01,99,97 ,99,56,500000090 36 5d 7d 01 6]}. 00000017 3c 72 65 67 75 6c 61 72 2d 73 6f 63 6b 65 74 2f 00000027 3e 00 7b 22 61 63 74 69 6f 6e 22 3a 22 73 75 62 >.{"acti on":"sub 00000037 73 63 72 69 62 65 22 2c 22 64 61 74 61 22 3a 22 scribe", "data":" 00000047 65 76 65 6e 74 73 22 7d 00 events"} .00000094 41 43 4b 01 ACK.00000098 7b 22 74 69 6d 65 73 74 61 6d 70 22 3a 5b 31 34 {"timest amp":[14000000A8 34 38 2c 34 33 34 39 32 35 2c 33 39 35 38 36 34 48,43492 5,395864000000B8 5d 2c 22 74 6f 70 69 63 22 3a 22 65 76 65 6e 74 ],"topic ":"event000000C8 73 22 2c 22 65 76 65 6e 74 22 3a 22 74 65 73 74 s","even t":"test000000D8 5f 65 76 65 6e 74 22 2c 22 6d 65 73 73 61 67 65 _event", "message000000E8 5f 69 64 22 3a 22 22 2c 22 64 61 74 61 22 3a 22 _id":"", "data":"000000F8 74 65 73 74 22 7d 01 test"}. 00000050 3c 72 65 67 75 6c 61 72 2d 73 6f 63 6b 65 74 2f 00000060 3e 00 7b 22 61 63 74 69 6f 6e 22 3a 22 75 6e 73 >.{"acti on":"uns 00000070 75 62 73 63 72 69 62 65 22 2c 22 64 61 74 61 22 ubscribe ","data" 00000080 3a 22 65 76 65 6e 74 73 22 7d 00 :"events "}.

publisher 协议交互

对应

flashbot janus,0,PUBLISH,0{"topic":"events","event":"test_event","message_id":"","data":"test"}---------------------------------------------->{"timestamp":[1448,434925,395595],"token":[100,52,97,53,56,51,54,99,57,97,50,52,50,57,52,57,55,48,52,102,48,100,99,53,102,55,56,101,101,97,53,98]},1<---------------------------------------------- 对应

00000000 3c 72 65 67 75 6c 61 72 2d 73 6f 63 6b 65 74 2f 00000010 3e 00 50 55 42 4c 49 53 48 00 7b 22 74 6f 70 69 >.PUBLIS H.{"topi 00000020 63 22 3a 22 65 76 65 6e 74 73 22 2c 22 65 76 65 c":"even ts","eve 00000030 6e 74 22 3a 22 74 65 73 74 5f 65 76 65 6e 74 22 nt":"tes t_event" 00000040 2c 22 6d 65 73 73 61 67 65 5f 69 64 22 3a 22 22 ,"messag e_id":"" 00000050 2c 22 64 61 74 61 22 3a 22 74 65 73 74 22 7d ,"data": "test"}00000000 7b 22 74 69 6d 65 73 74 61 6d 70 22 3a 5b 31 34 {"timest amp":[1400000010 34 38 2c 34 33 34 39 32 35 2c 33 39 35 35 39 35 48,43492 5,39559500000020 5d 2c 22 74 6f 6b 65 6e 22 3a 5b 31 30 30 2c 35 ],"token ":[100,500000030 32 2c 39 37 2c 35 33 2c 35 36 2c 35 31 2c 35 34 2,97,53, 56,51,5400000040 2c 39 39 2c 35 37 2c 39 37 2c 35 30 2c 35 32 2c ,99,57,9 7,50,52,00000050 35 30 2c 35 37 2c 35 32 2c 35 37 2c 35 35 2c 34 50,57,52 ,57,55,400000060 38 2c 35 32 2c 31 30 32 2c 34 38 2c 31 30 30 2c 8,52,102 ,48,100,00000070 39 39 2c 35 33 2c 31 30 32 2c 35 35 2c 35 36 2c 99,53,10 2,55,56,00000080 31 30 31 2c 31 30 31 2c 39 37 2c 35 33 2c 39 38 101,101, 97,53,9800000090 5d 7d 01 ]}.