# Dashboard

# Introduction

EMQX Dashboard is a web console provided by EMQX. You can view the running status of nodes and cluster, metrics, online status and subscriptions of clients through the Dashboard. You can also configure the plug-in on the Dashboard, stop and start the specified plug-in, manage the HTTP API key and most configurations of the EMQX cluster.

# Quick Start

If EMQX is installed on this machine, use your browser to open the address (opens new window). To log in, enter the default user name admin and the default password public to log in to Dashboard. If you forget to account information, click the Forgot Password button on the login page and follow the instructions or use management commands to reset or create a new account.

The Dashboard interface is shown in the following figure. It contains the left navigation bar, top control bar, and content area. The top control bar (red frame area) has three functions:

  • Alarm: EMQX alarm info. The number of alarms triggered by excessive resource usage and EMQX internal errors is displayed. Click to view the alarm list.
  • User: the currently logged-in Dashboard user, which can be used to log out and change passwords;
  • I18n: Dashboard displays Chinese / English by default according to the user's browser language. Click to switch languages.


# Monitor

On the monitoring page, you can view the running status of the current cluster. The functional area from top to bottom of the interface is as follows:

# Running Status

There are four cards at the top of the page, which are the message-out rate of the cluster, the message-in rate, the number of subscriptions, and the current number of connections.

# Node

Click the node drop-down list to switch to view the basic information of the node, including EMQX version, runtime, resource occupation, connection, and subscription data. Some data is defined as follows:

  • Memory: The current memory/maximum memory used by the Erlang VM, where the maximum memory is automatically applied to the system by EMQX depending on the resource usage.
  • Max Fds: Allow the current session/process to open the number of file handles. If this value is too small, it will limit the EMQX concurrency performance. When it is far less than the maximum number of connections authorized by the license, please refer to the tuning or contact the EMQ technical staff to modify;
  • Erlang Process, Connections, Topics, Subscriptions, Retained, Share Subscription: It is divided into two groups by / which are the current value and the maximum value.


# Latest Status

Click the button group on the right side of the node data area to switch to the recent cluster data graph. The graph values are the actual values during the sampling period:


# Nde details

Click the View More button below the node data to open the node details page, view the basic information of the current node, the listener* and connection status, and metrics.

# Listener

The listener is the list of the current EMQX listening network ports. The field information is as follows:

  • Protocol: listening network/application protocols, including protocol and function info:
    • mqtt:ssl: MQTT TCP TLS protocols, the default is 102400
    • mqtt:tcp: MQTT TCP protocols, the default is 102400
    • http:dashboard (opens new window): HTTP protocol used by Dashboard, the default is 512
    • http:management (opens new window): HTTP protocol used by EMQX REST API, the default is 512
    • mqtt:ws :MQTT over WebSocket, the default is 102400
    • mqtt:wss: MQTT over WebSocket TLS, the default is 102400
  • Address: Listen to the bound network address and port. Listen to all IP addresses by default;
  • Acceptors: listening the processor thread pool;
  • Connect: It contains a set of current/maximum values. The current value is the actual number of established connections. The maximum value is the maximum number of connections configured in the configuration file. If any listener exceeds the maximum value, a new connection cannot be established.

# About the maximum number of connections

The actual maximum connection depends on the license and configuration:

  1. The number of connections per listening protocol in the node cannot exceed the maximum number of connections in the configuration file;
  2. The total number of MQTT/MQTT over WebSocket protocol connections in the cluster cannot exceed the upper limit of the license.

Of course, system tuning and hardware will also affect the maximum number of connections. Please refer to tuning or contact EMQ technicians for confirmation.



# License

You can view the license information of the cluster by monitoring the license card at the bottom of the page:

  • Customer: Name of the company or department of the same business contract customer.
  • License usage: License specification and current usage.
  • Issuance of email: Same email address as a business contract customer.
  • License Edition: License edition, trial or official.

EMQ will issue a mailbox through email notification before the certificate expires. Please pay attention to receiving information so as not to miss the renewal time, which will affect the business.


# Connections

# Current Connections

The client list page displays a list of currently connected clients. Below lists some of the key information:

  • Client ID、Username: MQTT client ID and MQTT username, respectively. Click the Client ID to view the client details and subscription info.
  • IP Address: The client address + port.
  • Disconnect/Clean Session: For an online client, the connection will be disconnected and the session will be cleared. If the client is not online, clicking Clear Session will clear the session such as the client's subscription relationship.


# Basic Info

Click the Client ID to view the client details and subscription list. The basic information includes the selected client connection info and session info and includes key business information such as message traffic and message statistics.


# Subscription

The subscription contains information about the topics to which the selected client has subscribed:

  • Unsubscribe: Clicking the Unsubscribe button will delete the subscription relationship between the device and the topic. This operation is insensitive to the device.
  • Add: Specify a topic for the selected client proxy subscription.


# Rule

# Rule Engine

Use SQL to set rules to filter, encode, decode, and modify message data, and seamlessly forward processed data to data destinations such as databases, stream processing, and API gateways.

The Rule Engine not only provides a clear and flexible configurable business integration solution, but also simplifies the business development process, improves user usability, and reduces the degree of coupling between business systems and EMQX. Excellent infrastructure.

  • ID: Unique ID within the cluster, which can be used in CLI and REST API.
  • Topic: The MQTT topic or EMQX event topic that the Rule matches.
  • Monitor: Click to display the execution statistics of the selected Rule, including the number of rule hits and executions, and the number of successful/failed actions triggered.


# Create Rule

EMQX will trigger the Rule Engine when the message is published and the event is triggered, and the rules meeting the triggering conditions will execute their respective SQL statements to filter and process the context information of the message and event.

With the Actions, the Rule Engine can store the message processing results of a specified topic to the database, send them to the HTTP Server, forward them to the Kafka or RabbitMQ, and republish them to a new topic or another broker cluster like Azure IoT Hub. Each rule can allocate multiple Actions.

  1. Select the messages published to t/# and select all fields:
SELECT * FROM "message.publish" WHERE topic =~ 't/#'
  1. Select the message published to the t/a topic, and select the "x" field from the message payload in JSON format:
SELECT payload.x as x FROM "message.publish" WHERE topic =~ 't/a'

The Rule Engine uses the Events to process the built-in events of EMQX. the built-in events provide more sophisticated message control and client action processing capabilities, which can be used in the message arrival records of QoS 1 and QoS 2, the device up and down line records and other businesses.

  1. Select the client connected event, filter the device with Username 'emqx' and select the connection information:
SELECT clientid, connected_at FROM "client.connected" WHERE username = 'emqx'


# Resource

The resource instances (such as database instance and Web Server ) required by the Rule Engine action. Before creating a rule, you need to create the resources required for the relevant action and ensure that the resources are available.

# Resource list

  • ID: Unique ID within the cluster, which can be used in CLI and REST API.
  • Status: After the resource is created, each node in the cluster will establish a connection with the resource, click to expand the resource status on the node.
  • Delete: The resources being used by the Rule Engine cannot be deleted. Please delete the rules that depend on the selected resource before deleting.


# Create Resource

Click the Create to open the resource creation dialog. Select the resource type and enter the corresponding connection information to create the resource. Click Test to check the resource connectivity before creation.


# Schema Registry

Schema Registry supports Protobuf, Avro, and private message encoding parsing and processing, and can implement complex operations like message encryption, message compression, and binary-JSON message conversion.

# Alarm

The alarm shows the basic alarm information of EMQX, including current alarm and historical alarm. More advanced alarm, log and monitoring management is provided by EMQX Control Center, please contact EMQ technicians if necessary.


# Plugin

View the list of EMQX built-in plugins.

Unlike the command line plugin management, the plugin starts and stop operations on the Dashboard are synchronized to the cluster. If the plugin fails to start, check whether the configuration of each node in the cluster is correct. If any node fails to start, the plugin cannot be successfully started.


# Tool

It provides MQTT over WebScoket client test tool, which can realize the publish and subscribe test of multiple mqtt connections at the same time.

# Setting

Provides parameter configuration for the EMQX cluster and supports hot configuration. You can join and leave the cluster on the Dashboard.

# Basic

Some basic configuration items that can be hot updated inemqx.conf are opened in the settings. You can complete most configuration items such as whether to enable anonymous authentication, ACL cache events, and ACL cache switches without restarting EMQX.

The basic settings are organized in zones. By default, the external zone is associated with the listener on port 1883.

# Cluster

The cluster setting cannot change the cluster mode, but it can be used for manual cluster invitation nodes to join the cluster, and change the cluster parameter parameters such as static cluster and DNS cluster.

# General

# Application

In order to invoke the certificate of REST API, the application can query and adjust EMQX cluster information through REST API, and manage and operate the equipment.

After the application is created successfully, click the Application ID in the AppID column of the application list to view the AppID and Secret. You can edit the application status and expiration time, and create or delete an application.

# Users

Dashboard user account management, you can create, edit, delete users, if you forget the user password, you can reset the password through CLI.