摘要：注節點間如有防火墻，需要配置該端口段分布節點間通信使用連接端口范圍。

系統版本: ubuntu 16.04 LTS
EMQ 版本: 2.3.11

我使用的代理就是 EMQ(emqttd) 介紹或者詳細的配置可以到官網看看. 我這里只寫一些主要的配置.

我從官網下載的是 emqttd-ubuntu16.04-v2.3.11_amd64.deb 下載后直接雙擊安裝即可.

安裝后在控制臺輸出 sudo emqttd console 來啟動代理. 啟動后會輸出如下信息.

Exec: /usr/lib/emqttd/erts-9.0/bin/erlexec -boot /usr/lib/emqttd/releases/2.3.11/emqttd -mode embedded -boot_var ERTS_LIB_DIR /usr/lib/emqttd/erts-9.0/../lib -mnesia dir "/var/lib/emqttd/mnesia/emq@127.0.0.1" -config /var/lib/emqttd/configs/app.2018.10.03.18.37.02.config -args_file /var/lib/emqttd/configs/vm.2018.10.03.18.37.02.args -vm_args /var/lib/emqttd/configs/vm.2018.10.03.18.37.02.args -- console
Root: /usr/lib/emqttd
/usr/lib/emqttd
Erlang/OTP 20 [erts-9.0] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:32] [hipe] [kernel-poll:true]

starting emqttd on node "emq@127.0.0.1"
emqttd ctl is starting...[ok]
emqttd hook is starting...[ok]
emqttd router is starting...[ok]
emqttd pubsub is starting...[ok]
emqttd stats is starting...[ok]
emqttd metrics is starting...[ok]
emqttd pooler is starting...[ok]
emqttd trace is starting...[ok]
emqttd client manager is starting...[ok]
emqttd session manager is starting...[ok]
emqttd session supervisor is starting...[ok]
emqttd wsclient supervisor is starting...[ok]
emqttd broker is starting...[ok]
emqttd alarm is starting...[ok]
emqttd mod supervisor is starting...[ok]
emqttd bridge supervisor is starting...[ok]
emqttd access control is starting...[ok]
emqttd system monitor is starting...[ok]
emqttd 2.3.11 is running now
Eshell V9.0  (abort with ^G)
(emq@127.0.0.1)1> Load emq_mod_presence module successfully.
dashboard:http listen on 0.0.0.0:18083 with 4 acceptors.
mqtt:tcp listen on 127.0.0.1:11883 with 4 acceptors.
mqtt:tcp listen on 0.0.0.0:1883 with 16 acceptors.
mqtt:ws listen on 0.0.0.0:8083 with 4 acceptors.
mqtt:ssl listen on 0.0.0.0:8883 with 16 acceptors.
mqtt:wss listen on 0.0.0.0:8084 with 4 acceptors.
mqtt:api listen on 0.0.0.0:8080 with 4 acceptors.

也可以用這兩個命令來啟停
systemctl start emqttd
systemctl stop emqttd

## Console log. Enum: off, file, console, both
log.console = console

## Console log level. Enum: debug, info, notice, warning, error, critical, alert, emergency
log.console.level = error

## Console log file
## log.console.file = log/console.log

## Error log file
log.error.file = log/error.log

## Enable the crash log. Enum: on, off
log.crash = on

log.crash.file = log/crash.log

## Syslog. Enum: on, off
log.syslog = on

##  syslog level. Enum: debug, info, notice, warning, error, critical, alert, emergency
log.syslog.level = error

## Max ClientId Length Allowed.
mqtt.max_clientid_len = 1024

## Max Packet Size Allowed, 64K by default.
mqtt.max_packet_size = 64KB

設置 MQTT 客戶端最大允許閑置時間(Socket 連接建立, 但未收到 CONNECT 報文):

## Client Idle Timeout (Second)
mqtt.client.idle_timeout = 30

## Enable client Stats: on | off
mqtt.client.enable_stats = off

## Force GC: integer. Value 0 disabled the Force GC.
mqtt.conn.force_gc_count = 100

關于插件的配置參考這里

EMQ 消息服務器認證由一系列認證插件(Plugin)提供，系統支持按用戶名密碼、ClientID 或匿名認證.

系統默認開啟匿名認證(anonymous)，通過加載認證插件可開啟的多個認證模塊組成認證鏈:

           ----------------           ----------------           ------------
Client --> | Username認證 | -ignore-> | ClientID認證 | -ignore-> | 匿名認證 |
           ----------------           ----------------           ------------
                  |                         |                         |
                 |/                       |/                       |/
            allow | deny              allow | deny              allow | deny

如果開啟 用戶名和密碼 認證以及 客戶ID認證時, 我們會先判斷 用戶名和密碼 如果認證成功會忽略客戶端ID, 如果認證失敗則會去認證客戶端ID.

?? 客戶端ID也需要配置密碼.
用戶名和密碼以及客戶端ID都是唯一的, 而且連接到代理的會話也是唯一的. 二次連接代理會將前一個下線.