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MariaDB Flux Asset

Introduction

MariaDB is a popular SQL database management system that derives from MySQL. It offers a rich set of features and is widely recognized for its performance, reliability, and ease of use. MariaDB serves as a robust backend for a wide array of applications, from simple websites to complex transactional systems for large enterprises.

MariaDBMQTT facilitates seamless integration between MariaDB and various MQTT-enabled devices and services. It supports efficient data transfer from MariaDB to an MQTT broker and vice versa. This asset enables users to leverage MQTT for interacting with the database, allowing for both data extraction and insertion via MQTT messages. This interaction model supports real-time data processing and enhances the capabilities of IoT applications by linking them directly with MariaDB.

Features and Benefits

  • Seamless Communication: Enables seamless communication between MariaDB databases and MQTT clients, streamlining the exchange of data across platforms.
  • Real-time Query Execution: Facilitates real-time querying of the MariaDB database through MQTT messages, enabling dynamic data retrieval and manipulation.
  • Easy Integration: Simplifies the integration of MariaDB with your IoT projects, making it straightforward to connect database services with various IoT devices.
  • Dynamic Query Capability: Allows users to execute SQL queries directly through MQTT, enhancing flexibility and responsiveness.

Prerequisites

Before you install and configure the asset, make sure you have the following prerequisites:

  • Basic understanding of the MQTT protocol.
  • Basic understanding of SQL and MariaDB operations.
  • Access to an MQTT broker compatible with your setup.
  • MQTT Client software (such as MQTT Explorer or similar).
  • Access to a MariaDB database instance.

Asset installation

Using Coreflux HUB

Please refer the to general docs for asset installation through the Coreflux HUB.

Using Coreflux HUBLESS

Asset management and control are conducted using the MQTT protocol. Commands (payload) are sent to the $SYS/Coreflux/Command topic. The results of these commands are published to $SYS/Coreflux/Command/Output. The following steps will focus solely on the payload that needs to be sent.

  1. Connect to the Coreflux MQTT Broker using your preferred client.
  2. Login using your coreflux account: 
    -L myname@mydomain.com password`
  3. Check your available assets: 
    -l
  4. Install asset: 
    -I coreflux_mariadbmqtt
  5. If there were no issues during the installation you should receive a message on the $SYS/Coreflux/Command/Output: 
    Your coreflux_mariadbmqtt was installed with version <version> with the <asset_guid>. Let the magic begin!

Asset configuration

⚠ : If a parameter is not included in your asset's configuration and it is not required, a default value will be applied. Incorrect configuration may cause the asset to not work as intended.

ℹ : This configuration is presented using a hubless setup as an example. The key takeaway is the understanding of the parameters and their significance. If you are configuring the asset via Coreflux Hub, the same parameters and configurations apply.

MQTT Parameters

The MqttParameters in the JSON configuration define how to connect to an MQTT broker, specifying the communication details. The Address and Port indicate the broker's network location (in this case, 127.0.0.1 on port 1883), which is where the data will be sent to or received from. The parameters also detail authentication methods and the use of TLS for secure communication. This setup determines the pathway for data exchange between the device and the MQTT broker, facilitating the monitoring or control of device operations.

Parameter Description Required Example Default Value
Port Port number on which the MQTT broker is running. Yes 1883 1883
Address IP address or hostname of the MQTT broker. Yes "iot.coreflux.cloud" "127.0.0.1"
IsAnonymous Indicates if the connection is anonymous (no username/password required). No true true
Username Username for authentication, if not anonymous. No "" (empty string) "" (empty string)
Password Password for authentication, if not anonymous. No "" (empty string) "" (empty string)
WithTLS Specifies whether TLS encryption is enabled for secure communication. No true false
ClientId Used to uniquely to identify the client to the MQTT broker. Yes Client1 Random.Name.Generator

Example:

{
  "MqttParameters": {
    "Port": 1883,
    "Address": "iot.coreflux.cloud",
    "IsAnonymous": true,
    "Username": "",
    "Password": "",
    "WithTLS": false,
    "ClientId": "ClientId1"
  }
}

SQL Parameters

The SQL in the JSON configuration outline the setup for SQL communication between the asset and a MariaDB database. These parameters are essential for establishing a connection to the database, enabling the asset to execute queries and manage data effectively. They include specifying the server address, port, database name, and credentials for authentication. This configuration ensures the asset can interact with the database securely and efficiently. Additionally, the query timeout setting helps manage the performance of data interactions, preventing long waits in case of database response delays.

Parameter Description Required Example Default Value
ServerAddress SQL Server IP Address. Yes "127.0.0.1" "127.0.0.1"
ServerPort SQL Server Port. Yes 3306 1893
DataBaseName Name of the database to connect to. Yes "example-database" "DB"
Username Username for authentication with the SQL server. Yes "user" "user"
Password Password for authentication with the SQL server. Yes "pass" "pass"
QueryTimeoutInSeconds Maximum duration in seconds before a query is terminated if not done. Yes 10 10

Example:

{
  "MqttParameters": {
    "Port": 1883,
    "Address": "iot.coreflux.cloud",
    "IsAnonymous": true,
    "Username": "",
    "Password": "",
    "WithTLS": false,
    "ClientId": "ClientId1"
  },
  "SQL": {
    "ServerAddress": "test.address",
    "ServerPort": 3306,
    "Databasename": "example-database",
    "Username": "user",
    "Password": "pass",
    "QueryTimeoutInSeconds": "10"
    }
}

Tags

Tags are crucial components that facilitate both querying from and writing to your MariaDB database via MQTT interactions. Each Tag establishes a direct link between a database operation and an MQTT topic, enabling not only the execution of SQL queries but also the transmission of responses back to MQTT clients. These tags configure the specifics of the SQL operations and the MQTT communication, including the SQL query to execute, the MQTT topics for initiating requests and receiving responses, and the data formatting preferences.

Parameter Description Required Example Default Value
Name Unique Tag identifier. Yes "TemperatureData" "TagName"
Route Specifies the direction of data flow within the system. Acceptable values are: 'ToSubscribers' (0), 'ToOther' (1). Yes 0 1
Publish Chose how data is sent. Acceptable values are: 'Update' (0), 'Cyclic' (1), 'Once' (2) Yes 0 2
PublishCycle Specifies the interval for publishing messages when 'publish' is set to 'Cyclic'. Must be a value between 1 and 86,400 seconds (24 hours). No 500 1
MqttTopic Unique topic connecting with the specified Register. Yes "room/temp" "mqtt/topic"
MqttRetain Defines if the message should be retained. Options are: true or false. Yes true false
MqttFeedbackTopic Unique topic that will receive the feedback from SQL query execution. Yes "feedback/topic" "feedback/topic"
Query The SQL query string that is to be executed. Yes INSERT INTO data(temp) VALUES ({value.csv.temp}) "SELECT * FROM table"
OutputType The format of the SQL query result. Options are: Raw (0), Csv(1), and Json(2). Yes 2 0
QualityOfService Defines the level of delivery assurance for MQTT messages. The options are: AtMostOnce (0), AtLeastOnce(1), ExactlyOnce(1). Yes 2 0

Example:

{
  "MqttParameters": {
    "Port": 1883,
    "Address": "iot.coreflux.cloud",
    "IsAnonymous": true,
    "Username": "",
    "Password": "",
    "WithTLS": false,
    "ClientId": "ClientId1"
  },
  "SQL": {
    "ServerAddress": "test.address",
    "ServerPort": 3306,
    "Databasename": "example-database",
    "Username": "user",
    "Password": "pass",
    "QueryTimeoutInSeconds": "10"
    },
  "Tags": [
    {
      "Name": "TemperatureData",
      "Route": 0,
      "Publish": 0,
      "PublishCycle": 350,
      "MqttTopic": "room/temp",
      "MqttRetain": true,
      "MqttFeedbackTopic": "feedback/topic",
      "Query": "SELECT temperature FROM data",
      "OutputType": 1,
      "QualityOfService": 0
    }
  ]
}

⚠ Warning: Only one query can be executed per MQTT event. Ensure your SQL statements are designed accordingly to avoid unexpected behavior.

Data Insertion Guide

This Asset supports multiple data formats for inserting records into the data table: Raw, CSV, and JSON. Below is a quick reference guide on how to send data in each format.

Format SQL Query Payload
Raw INSERT INTO table(age) VALUES ({value}); 15
CSV INSERT INTO table(name,position) VALUES ('{value.csv.name}', '{value.csv.position}'); name, position
Rita, Developer
JSON INSERT INTO table(age, name) VALUES ({value.json.age}, '{value.json.name}'); { "age": 25, "name": "John"}

Explanation

  • Raw: The value is passed directly into the SQL query.
  • CSV: Data is formatted as CSV, with field names and values separated by new lines.
  • JSON: Data is sent in JSON format, and the fields are referenced in the SQL query using dot notation.

Saving the configuration

Asset management and control are conducted using the MQTT protocol. Commands (MQTT payload) are sent to the $SYS/Coreflux/Command topic. The results of these commands are published to $SYS/Coreflux/Command/Output. The following steps will focus solely on the payload that needs to be sent.

ℹ : Configuration requires the user to be logged in and have an asset installed. If these requirements are not met, please refer to the installation section.

  1. Save configuration: 
    -assetConfigSave <asset_guid> <configuration>`

    ℹ : The asset asset_guid can be obtained by consulting the $SYS/Coreflux/Assets topic.

Example:

-assetConfigSave assetName {
  "MqttParameters": {
    "Port": 1883,
    "Address": "iot.coreflux.cloud",
    "IsAnonymous": true,
    "Username": "",
    "Password": "",
    "WithTLS": false,
    "ClientId": "ClientId1"
  },
  "SQL": {
    "ServerAddress": "test.address",
    "ServerPort": 3306,
    "Databasename": "example-database",
    "Username": "user",
    "Password": "pass",
    "QueryTimeoutInSeconds": "10"
    },
  "Tags": [
    {
      "Name": "TemperatureData",
      "Route": 0,
      "Publish": 0,
      "PublishCycle": 350,
      "MqttTopic": "room/temp",
      "MqttRetain": true,
      "MqttFeedbackTopic": "feedback/topic",
      "Query": "SELECT temperature FROM data",
      "OutputType": 1,
      "QualityOfService": 0
    }
  ]
}
  1. Check if the configuration was saved (optional) : 
    -assetConfigLoad <asset_guid>

Using the asset

⚠ : It is important to understand that the flow of data between the broker and the device highly depends on the configuration of both the asset and the device. In case of unexpected results, please verify the configuration and/or check the logs for any possible errors.

With Coreflux HUB

Please refer the to general docs for asset installation through the Coreflux HUB.

With Coreflux HUBLESS

Asset management and control are conducted using the MQTT protocol. Commands (MQTT payload) are sent to the $SYS/Coreflux/Command topic. The results of these commands are published to $SYS/Coreflux/Command/Output. The following steps will focus solely on the payload that needs to be sent.

ℹ : The asset guid can be obtained by consulting the $SYS/Coreflux/Assets topic.

Run asset

  1. Run asset:
-R <asset_guid>

Stop asset

  1. Stop asset:
-S <asset_guid>

Logs

Logs are essential for monitoring and debugging your system. They provide insight into the operation of your assets and can help identify and resolve issues promptly.

With Coreflux HUB

On Coreflux HUB, the logs are displayed in the "Log" section of the asset configuration.

With MQTT Explorer

To display logs in MQTT Explorer, follow these steps:

  1. Publish the following command to the $SYS/Coreflux/Command topic:

-addTraceLog topic=topic/to/show/log level=Error/Information/Warning messageContains=(assetID)
2. The logs will be shown on the $SYS/Coreflux/Log/Traces/topic/to/show/log topic.

Example1:

To display informational logs, use:

-addTraceLog topic=log/inf level=Information

Note : This will display the Logs "Information" of all the assets

Example2:

To display error logs, from a specific asset, use:

-addTraceLog topic=log/mariadb/err level=Error messageContains=assetID

Note : This will display the Logs "Error" of a specific asset

Note: To display all three types of logs (Error, Information, and Warning), you will need to repeat this process three times, one for each log level. three times, one for each log level.