RobustMQ

User Registration
1.1 The MQTT Broker has enabled user authentication, which requires clients to provide a valid username and password for verification before publishing or subscribing to messages. Clients that do not pass the verification will be unable to communicate with the Broker. This feature can enhance system security by preventing unauthorized access.
Register a user
console
```
% ./bin/robust-ctl mqtt mqtt user create --username=testp --password=7355608
Created successfully!
```
Delete a user
console
```
% ./bin/robust-ctl mqtt mqtt user delete --username=testp
Deleted successfully!
```
1.2 View created users
console
```
% ./bin/robust-ctl mqtt mqtt user list
+----------+--------------+
| username | is_superuser |
+----------+--------------+
| admin    | true         |
+----------+--------------+
| testp    | false        |
+----------+--------------+
```

TODO Subscribe and Publish

publish

console

% ./bin/robust-ctl mqtt mqtt --server=127.0.0.1:1883 publish --username=admin --password=pwd123 --topic=test/topic1 --qos=0
able to connect: "127.0.0.1:1883"
you can post a message on the terminal:
1
> You typed: 1
2
> You typed: 2
3
> You typed: 3
4
> You typed: 4
5
> You typed: 5
^C>  Ctrl+C detected,  Please press ENTER to end the program.

subscribe

console

% ./bin/robust-ctl mqtt mqtt --server=127.0.0.1:1883 subscribe --username=admin --password=pwd123 --topic=test/topic1 --qos=0

able to connect: "127.0.0.1:1883"
subscribe success
payload: 1
payload: 2
payload: 3
payload: 4
payload: 5
^C Ctrl+C detected,  Please press ENTER to end the program.
End of input stream.

send retain message

console

    % ./bin/robust-ctl mqtt mqtt --server=127.0.0.1:1883 publish --username=admin --password=pwd123 --topic=\$share/group1/test/topic1 --qos=1 --retained
    able to connect: "127.0.0.1:1883"
    you can post a message on the terminal:
    helloworld!
    > You typed: helloworld!
    published retained message

console

    % ./bin/robust-ctl mqtt mqtt --server=127.0.0.1:1883 subscribe --username=admin --password=pwd123 --topic=\$share/group1/test/topic1 --qos=0
    able to connect: "127.0.0.1:1883"
    subscribe success
    Retain message: helloworld!

Enable Slow Subscription Feature
3.1 The slow subscription statistics function is mainly used to calculate the time (latency) it takes for the Broker to complete message processing and transmission after the message arrives at the Broker. If the latency exceeds the threshold, we will record a related piece of information in the cluster's slow subscription log. Operations personnel can query slow subscription records across the entire cluster using commands to address issues based on this information.
Enable slow subscription
console
```
 % ././bin/robust-ctl mqtt mqtt slow-sub --enable=true
 The slow subscription feature has been successfully enabled.
```
3.2 How to view slow subscription records
After enabling the slow subscription statistics function, the cluster begins recording slow subscriptions. To query corresponding slow subscription records, clients can enter the following command:
console
```
 % ././bin/robust-ctl mqtt mqtt slow-sub --query=true
 +-----------+-------+----------+---------+-------------+
 | client_id | topic | sub_name | time_ms | create_time |
 +-----------+-------+----------+---------+-------------+
```
3.3 Sorting Functionality
To obtain more slow subscription records and sort them in ascending order from smallest to largest, you can use the following command:
console
```
 % ././bin/robust-ctl mqtt mqtt slow-sub --list=200 --sort=asc
 +-----------+-------+----------+---------+-------------+
 | client_id | topic | sub_name | time_ms | create_time |
 +-----------+-------+----------+---------+-------------+
```
3.4 Filtering Query Functionality
For slow subscription queries, filtering queries are also supported. You can retrieve filtered results by fields such as topic, sub_name, and client_id. By default, the results are sorted in descending order from largest to smallest. Refer to the usage command below:
console
```
% ././bin/robust-ctl mqtt mqtt slow-sub --topic=topic_test1 --list=200
+-----------+-------+----------+---------+-------------+
| client_id | topic | sub_name | time_ms | create_time |
+-----------+-------+----------+---------+-------------+
```