# Development Related Questions

# Which protocol connections are supported?

EMQX Cloud deployment supports MQTT over TLS/SSL and WebSockets over TLS/SSL protocol connections.

If you need other protocol support, you can submit a ticket or send an email (cloud-support@emqx.io) to us.

# How to bind a domain name?

When you create a deployment in EMQX Cloud, you will be given an MQTT connection address, which is displayed as a domain in the deployment.

You may already have your own domain and would like to be able to bind to it.

Note: mqtts and wss ports will not be available on Standard after the domain is bound.

# Steps

  1. Let's assume you have the top-level domain abc.com and want to access the MQTT service as mqtt.abc.com, and your deployment on EMQX Cloud has a connection address of xxx.emqx.cloud.

  2. Point the CNAME record from mqtt.abc.com to xxx.emqx.cloud in your domain settings panel.

  3. Once the DNS resolution has taken effect, you can connect to the MQTT service via mqtt.abc.com.

# How to set up NAT gateway configuration?

NAT is only supported for Professional plan. You can enable NAT gateway in Valued-Added Service.

# Will cluster scaling affect device connectivity?

It will cause an interruption to the connectivity for a few seconds.

# How do I connect my own services to the MQTT service via local network when I have built a VPC peer-to-peer connection?

If you need an internal network connection to deploy to MQTT, you will need to submit a ticket and contact us to open SLB.

# Is API supported?

Yes. An HTTP API is provided for integration with external systems, such as querying client information, posting messages, and creating rules.

Find more here REST API

# What kind of TLS/SSL authentication is supported?

Support one-way, two-way, and custom signature for configuration.

# How to integrate with other systems?

You can use data integrations to integrate with other applications. Check Data Integrations for more details.

# The authentication data of the device is stored in my own database. Can I do the authentication of MQTT connections through my own database?

It is not yet supported to get data directly from your own database. You can import data from csv files together. Or you can submit a ticket or send an email (cloud-support@emqx.io) to us.

# How long can device logs be kept in the console?

EMQX Cloud does not keep device communication logs, only deployment event logs, which are kept for 7 days by default.

# How long can device events be stored in the console?

Device event data can be saved permanently.

# How to calculate sessions?

The definition for session: The number of sessions is calculated by adding the number of connected clients and the disconnected clients with sessions retained in the broker. Connected clients are those that connect to the broker after CONNECT, including those that are not disconnected within the keepAlive span. Disconnected clients that keep a session are clients that are offline but have CleanSession set to false, and such clients are counted in the session count. When a device DISCONNECT goes offline, or if it has not communicated for more than the keepAlive span, the device will go offline and will not be counted in the number of sessions.