Questions on the Iot Hub quotas and throttling. RRS feed

  • Question

  • Questions on the Iot Hub quotas and throttling.
    https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-devguide-quotas-throttling  )

    1. Accroding to the document,
    the one S1 instance can accept 100/sec connections and can receive 100/sec Device-to-cloud messages.

    In case there's 100000 clients and they try to connect simultaneously, what's the connections result most clients would get?
    (They get connection error? or the Client SDK handles it and retry connection interally? )

    2. In case a use tries to send a message to all of the clients at once and calls 100000 cloud-to-device message request at once,
    what would be the results the user get?
    (Success for 100 and failures for the rest 99900?
    Or Service Client SDK retries internally till it get success?
    Or the IoTHub instance accepts all the requests and then send 100 messages per sec for 1000 secs?)

    3. In the table, for S1 Instance,

      Cloud-to-device sends : 100/min/unit
      Cloud-to-device receives  : 1000/min/unit
    (only when device uses HTTP)

    -> Could anyone explain me what they means and what's the difference of 'Cloud-to-device sends' and 'Cloud-to-device receives' ?

    Thanks for reading.
    Monday, March 13, 2017 1:04 AM


  • Hi Jae Eun,

    Some answers for you in order of your asks:

    1. After your hub hits the throttle, the clients will start getting 429 (Throttled) errors.
    2. Similar to above, once your hub hits the throttle for sending C2D messages, the sender will get a 429 (Throttled) error. We recommend you use a device job to send messages to a large set of devices.
    3. "C2D sends" rate is the rate at which the user sends messages to IoT Hub to be passed on to the devices. The "C2D receives" rate is the rate at which devices can poll for C2D messages. Because HTTP is not a continuous connection (by the definition of the HTTP protocol), devices have to poll the service for new C2D messages, and we throttle that polling.



    • Marked as answer by jaeeunchoi Wednesday, March 15, 2017 4:20 AM
    Tuesday, March 14, 2017 8:15 PM