Azure Event Grid namespace MQTT terminology

This article defines key terms relevant to Event Grid namespaces and MQTT resources.

Namespace

An Event Grid namespace is a declarative space that provides a scope to all the nested resources or subresources such as topics, certificates, clients, client groups, topic spaces, permission bindings.

Using the namespace, you can organize the subresources into logical groups and manage them as a single unit in your Azure subscription. Deleting a namespace deletes all the subresources in the namespace.

It gives you a unique fully qualified domain name (FQDN). A namespace exposes two endpoints:

• An HTTP endpoint to support general messaging requirements using Namespace Topics.
• An MQTT endpoint for IoT messaging or solutions that use MQTT.

A namespace also provides DNS-integrated network endpoints and a range of access control and network integration management features such as IP ingress filtering and private links. It's also the container of managed identities used for all contained resources that use them.

Namespace is a tracked resource with tags and location properties, and once created, it can be found on resources.azure.com.

The name of the namespace can be 3-50 characters long. It can include alphanumeric, and hyphen(-), and no spaces. The name needs to be unique per region.

Throughput units

Throughput units (TUs) control the capacity of Azure Event Grid namespace and allow user to control capacity of their namespace resource for message ingress and egress. For more information about limits, see Azure Event Grid quotas and limits.

Certificate / cert

A certificate is a form of asymmetric credential. It's a combination of a public key from an asymmetric keypair and a set of metadata that describes the valid uses of the keypair. If the keypair of the issuer is the same keypair as the certificate, the certificate is self-signed. Third-party certificate issuers are sometimes called certificate authorities (CA). For more information about client authentication, see MQTT client authentication.

Client

A client is a device or an application that can publish or subscribe to MQTT messages. For more information about client configuration, see MQTT clients.

Client attributes

Client attributes are a set of key-value pairs that provide descriptive information about the client. You use client attributes to create client groups and as variables in topic templates. For example, client type is an attribute that provides the client's type. For more information about client configuration, see MQTT clients.

Client group

A client group is a collection of clients. You can group clients together by using common client attributes. You can give client groups permissions to publish or subscribe to a specific topic space. For more information about client group configuration, see MQTT client groups.

Permission bindings

A permission binding grants access to a specific client group to either publish or subscribe on a specific topic space. For more information about permission bindings, see MQTT access control.

Topic filter

An MQTT topic filter is an MQTT topic that can include wildcards for one or more of its segments, allowing it to match multiple MQTT topics. It simplifies subscription declarations because one topic filter can match multiple topics.

Topic space

A topic space is a set of topic templates. It simplifies access control management by enabling you to scope publish or subscribe access for a client group to a group of topics at once instead of individual topics. For more information about topic space configuration, see MQTT topic spaces.

Topic template

Topic templates, an extension of the topic filter, support variables. You use them for fine-grained access control within a client group.

Next steps

• Learn about creating an Event Grid namespace.
• Learn about MQTT broker feature in Azure Event Grid.
• Learn more about MQTT clients.
• Learn how to Publish and subscribe MQTT messages by using Event Grid namespace.