1.消息队列emqtt

2.x版本之前都叫emqtt，3.x之后版本都叫emqx

下载地址：https://www.emqx.io/cn/downloads#broker

安装部署

　　1.下载软件包后上传到服务器，解压

1	`unzip emqttd-centos7-v2.0.zip`

　　2.以调试模式启动，检查服务是否正常

[root@localhost emqttd]# cd emqttd && ./bin/emqttd console
Exec: /root/emqttd/erts-9.0/bin/erlexec -boot /root/emqttd/releases/2.3.7/emqttd -mode embedded -boot_var ERTS_LIB_DIR /root/emqttd/erts-9.0/../lib -mnesia dir "/root/emqttd/data/mnesia/emq@127.0.0.1" -config /root/emqttd/data/configs/app.2020.05.23.23.38.19.config -args_file /root/emqttd/data/configs/vm.2020.05.23.23.38.19.args -vm_args /root/emqttd/data/configs/vm.2020.05.23.23.38.19.args -- console
Root: /root/emqttd
/root/emqttd
Erlang/OTP 20 [erts-9.0] [source] [64-bit] [smp:2:2] [ds:2:2:10] [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 2.3.7 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.

　　3.查看服务启动状态

[root@localhost ~]# ./emqttd/bin/emqttd_ctl status
Node 'emq@127.0.0.1' is started
emqttd 2.3.7 is running　

　　4.如果服务启动正常，更改为后台启动，启动错误日志将输出到log目录下

1	`./bin/emqttd` `start`

　　5.EMQ 消息服务器提供了状态监控 URL

1	`http://localhost:8080/status`

　　6.控制台 URL: http://localhost:18083/ ，默认登录用户名: admin, 密码: public。

　　7.停止服务器:

1	`./bin/emqttd` `stop`

调试配置

1.EMQ 2.0 消息服务器默认占用的 TCP 端口包括

1883        #MQTT 协议端口
8883        #MQTT/SSL 端口
8083        #MQTT/WebSocket 端口
8084     #MQTT/WebSocket/SSL监听端口
8080        #HTTP API 端口
18083   #Dashboard 管理控制台端口
11883   #MQTT/TCP内部协议监听端口
 
4369     #emq集群通信端口
6369     #erlang集群间通信端口　　

2.可通过 etc/emq.conf 配置文件的 ‘listener’ 段落设置（18083是由emq_dashboard插件控制，配置文件在etc/plugins/emq_dashboard.conf）

## TCP Listener: 1883, 127.0.0.1:1883, ::1:1883
listener.tcp.external = 0.0.0.0:1883
 
## SSL Listener: 8883, 127.0.0.1:8883, ::1:8883
listener.ssl.external = 8883
 
## External MQTT/WebSocket Listener
listener.ws.external = 8083
 
## HTTP Management API Listener
listener.api.mgmt = 127.0.0.1:8080

3.EMQ 消息服务器主要配置文件

etc/emq.conf        #EMQ 2.0 消息服务器配置文件
etc/acl.conf        #EMQ 2.0 默认ACL规则配置文件
etc/plugins/*.conf  #EMQ 2.0 各类插件配置文件　　

4.主配置文件

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#集群名称
cluster.name = emqttd@192.168.1.1
 
#自动发现策略
#manual 手工命令创建集群
#static 静态节点列表自动集群
#mcast  UDP 组播方式自动集群
#dns    DNS A 记录自动集群
#etcd   通过 etcd 自动集群
#k8s    Kubernetes 服务自动集群
cluster.discovery = manual
 
#启用集群自愈
cluster.autoheal = on
 
#自动清除宕机节点
cluster.autoclean = 5m
 
#Erlang 虚拟机允许的最大进程数，一个 MQTT 连接会消耗2个 Erlang 进程，所以参数值 > 最大连接数 * 2
node.process_limit 256000   
 
#Erlang 虚拟机允许的最大 Port 数量，一个 MQTT 连接消耗1个 Port，所以参数值 > 最大连接数
node.max_ports  65536
 
#Erlang 分布节点间通信使用 TCP 连接端口范围。注: 节点间如有防火墙，需要配置该端口段
node.dist_listen_min    6369
node.dist_listen_max 6379
 
#日志参数
log.console = console
log.console.level = error
log.error.file = log/error.log
log.crash = on
log.crash.file = log/crash.log
log.syslog = on
log.syslog.level = error
 
#ClientId 最大允许长度
mqtt.max_clientid_len = 1024
 
#MQTT 最大报文尺寸
mqtt.max_packet_size = 64KB
 
#MQTT 客户端最大允许闲置时间(Socket 连接建立，但未收到 CONNECT 报文):
mqtt.client.idle_timeout = 30
 
#启用客户端连接统计
mqtt.client.enable_stats = off
 
#强制 GC 设置
mqtt.conn.force_gc_count = 100
 
#允许任意客户端登录
mqtt.allow_anonymous = true
 
#默认访问控制(ACL)文件
mqtt.acl_nomatch = allow
mqtt.acl_file = etc/acl.conf
mqtt.session.upgrade_qos = off
mqtt.session.max_inflight = 32
mqtt.session.retry_interval = 20s
mqtt.session.max_awaiting_rel = 100
mqtt.session.await_rel_timeout = 20s
mqtt.session.enable_stats = off
mqtt.session.expiry_interval = 2h
 
#MQTT 消息队列参数设置
#队列类型。simple: 简单队列，priority: 优先级队列
mqtt.mqueue.type = simple
#主题(Topic)队列优先级设置
mqtt.mqueue.priority = topic/1=10,topic/2=8
#队列长度, infinity 表示不限制
mqtt.mqueue.max_length = 0
#解除告警水位线
mqtt.mqueue.low_watermark = 20%
#队列满告警水位线
mqtt.mqueue.high_watermark = 60%
#是否缓存 QoS0 消息
mqtt.mqueue.store_qos0 = true
 
#系统发布 $SYS 消息周期
mqtt.broker.sys_interval = 60s
 
#发布订阅(PubSub)参数设置
mqtt.pubsub.pool_size = 8
mqtt.pubsub.by_clientid = true
mqtt.pubsub.async = true
 
#桥接(Bridge)参数设置
mqtt.bridge.max_queue_len = 10000
mqtt.bridge.ping_down_interval = 1s
 
#插件(Plugin) 配置目录设置
mqtt.plugins.etc_dir = etc/plugins/
mqtt.plugins.loaded_file = data/loaded_plugins
 
#MQTT/TCP 监听器 - 1883
listener.tcp.external = 0.0.0.0:1883
listener.tcp.external.acceptors = 16
listener.tcp.external.max_clients = 102400
listener.tcp.external.access.2 = allow all
listener.tcp.external.backlog = 1024
listener.tcp.external.buffer = 4KB
listener.tcp.external.nodelay = true
listener.tcp.internal = 127.0.0.1:11883
listener.tcp.internal.acceptors = 16
listener.tcp.internal.max_clients = 102400
listener.tcp.internal.backlog = 512
listener.tcp.internal.tune_buffer = on
listener.tcp.internal.buffer = 1MB
listener.tcp.internal.recbuf = 4KB
listener.tcp.internal.sndbuf = 1MB
listener.tcp.internal.nodelay = true
 
#MQTT/SSL 监听器 - 8883
listener.ssl.external = 8883
listener.ssl.external.acceptors = 16
listener.ssl.external.max_clients = 1024
listener.ssl.external.access.1 = allow all
listener.ssl.external.handshake_timeout = 15
listener.ssl.external.keyfile = etc/certs/key.pem
listener.ssl.external.certfile = etc/certs/cert.pem
 
#MQTT/WebSocket 监听器 - 8083
listener.ws.external = 8083
listener.ws.external.acceptors = 4
listener.ws.external.max_clients = 64
listener.ws.external.access.1 = allow all
 
#MQTT/WebSocket/SSL 监听器 - 8084
listener.wss.external = 8084
listener.wss.external.acceptors = 4
listener.wss.external.max_clients = 64
listener.wss.external.access.1 = allow all
listener.wss.external.handshake_timeout = 15s
listener.wss.external.keyfile = {{ platform_etc_dir }}/certs/key.pem
listener.wss.external.certfile = {{ platform_etc_dir }}/certs/cert.pem
 
#HTTP API 监听器 - 8080
listener.api.mgmt = 127.0.0.1:8080
listener.api.mgmt.acceptors = 4
listener.api.mgmt.max_clients = 64
listener.api.mgmt.access.1 = allow all
 
#Erlang 虚拟机监控设置
sysmon.long_gc = false
sysmon.long_schedule = 240
sysmon.large_heap = 8MB
sysmon.busy_port = false
sysmon.busy_dist_port = true

分布式集群

默认方式为手动加入集群，配置位于

1	`cluster.discovery = manual`

以三台机器为例，每台主机更改配置文件中的node.name

#节点1
node.name = emq@192.168.2.4
 
#节点2
node.name = emq@192.168.2.6
 
#节点3
node.name = emq@192.168.2.100

分别启动三个节点

1 2	`#节点1,2,3都是这个命令` `./bin/emqttd` `start`

加入集群

1 2	`#只需要在其中额外两台节点添加就可以` `./bin/emqttd_ctl` `cluster` `join` `emq@192.168.2.100`

查看集群节点状态

#任意一台都可以查看
./bin/emqttd_ctl cluster status
Cluster status: [{running_nodes,['emq@192.168.2.4','emq@192.168.2.100',
                                 'emq@192.168.2.6']}]

节点退出集群

#主动离开方式
./bin/emqttd_ctl cluster leave
 
#被动离开方式，被踢出去
./bin/emqttd_ctl cluster remove emq@192.168.1.1

上面是手动方式创建的集群，下面在配置文件中规定好集群，改好配置，直接启动就好了

cluster.discovery = static
 
##--------------------------------------------------------------------
## Cluster with static node list
 
cluster.static.seeds = emq1@127.0.0.1,ekka2@127.0.0.1