purpose of Azure iot hub device-to-cloud partitions

Question

When creating a new Azure IOT Hub you are asked how many device-to-cloud partitions you need. You can select between 2-32 partitions for standard tiers.

I understand that the SKU and number of units determine the maximum daily quota of messages that you can send to IOT Hub. And that it is recommended to shard your devices into multiple IOT hubs to smooth traffic bursts. However, device-to-cloud partitions need clarification.

1>> What is the purpose of those device-to-cloud partitions under a single IOT hub?

2>> How are we supposed to take advantage of those IOT Hub device-to-cloud partitions? 

Thanks.

Answer 1

1>> What is the purpose of those device-to-cloud partitions under a single IOT hub?

Partition property is setting for Event Hub-compatible messaging endpoint(messages/events) built in Azure IoT Hub. From here we can see "partitions" is a concept belongs to Event Hub.

Event Hubs is designed to allow a single partition reader per consumer group. A single partition within a consumer group cannot have more than 5 concurrent readers connected at any time. More partitions enables you to have more concurrent readers processing your data, improving your aggregate throughput.

Ref: Built-in endpoint: messages/events and How many partitions do I need?

2>> How are we supposed to take advantage of those IOT Hub device-to-cloud partitions?

Event Hubs has two primary models for event consumption: direct receivers and higher-level abstractions, such as EventProcessorHost. Direct receivers are responsible for their own coordination of access to partitions within a consumer group.

Ref:Event consumers.

More information about the partitioning model of Azure Event Hubs are here.