使用rpm包安裝，可以到官網（“http://www.emqtt.com/downloads”）下載
配置文件目錄：/etc/emqttd/
修改配置文件，如下：
## Allow Anonymous Authentication.
##
## Notice: Disable the option for production deployment.
##
## Value: true | false
mqtt.allow_anonymous = false
## Maximum MQTT packet size allowed.
#### Value: Bytes
##
## Default: 64K
mqtt.max_packet_size = 6400KB
使用mysql插件進行認證，需要關閉其他認證插件；需要注意用戶口令是否需要加密以及加密方式“auth.mysql.password_hash = plain”
##--------------------------------------------------------------------
## MySQL Auth/ACL Plugin
##--------------------------------------------------------------------
## MySQL server address.
##
## Value: Port | IP:Port
##
## Examples: 3306, 127.0.0.1:3306, localhost:3306
auth.mysql.server = 127.0.0.1:3306
## MySQL pool size.
##
## Value: Number
auth.mysql.pool = 8
## MySQL username.
##
## Value: String
auth.mysql.username = root
## MySQL password.
##
## Value: String
## auth.mysql.password =
## MySQL database.
##
## Value: String
auth.mysql.database = emqttd
## Variables: %u = username, %c = clientid
## Authentication query.
##
## Note that column names should be 'password' and 'salt' (if used).
## In case column names differ in your DB - please use aliases,
## e.g. "my_column_name as password".
##
## Value: SQL
##
## Variables:
## - %u: username
## - %c: clientid
##
auth.mysql.auth_query = select password from mqtt_user where username = '%u' limit 1
## auth.mysql.auth_query = select password_hash as password from mqtt_user where username = '%u' limit 1
## Password hash.
##
## Value: plain | md5 | sha | sha256 | bcrypt
auth.mysql.password_hash = plain
## sha256 with salt prefix
## auth.mysql.password_hash = salt,sha256
## bcrypt with salt only prefix
## auth.mysql.password_hash = salt,bcrypt
## sha256 with salt suffix
## auth.mysql.password_hash = sha256,salt
## pbkdf2 with macfun iterations dklen
## macfun: md4, md5, ripemd160, sha, sha224, sha256, sha384, sha512
## auth.mysql.password_hash = pbkdf2,sha256,1000,20
## Superuser query.
##
## Value: SQL
##
## Variables:
## - %u: username
## - %c: clientid
auth.mysql.super_query = select is_superuser from mqtt_user where username = '%u' limit 1
## ACL query.
##
## Value: SQL
##
## Variables:
## - %a: ipaddr
## - %u: username
## - %c: clientid
auth.mysql.acl_query = select allow, ipaddr, username, clientid, access, topic from mqtt_acl where ipaddr = '%a' or username = '%u' or username = '$all' or clientid = '%c'