Which Allocation Policy to Use for Distributing Device Connections in Azure IoT Solution?
Question
You are working for a company which is about setting up a country-wide environmental monitoring system for real-time air pollution monitoring.
The system, in the first stage, will consist of 10000 sensor end-devices deployed all over three regions.
Your task is to connect these devices to an Azure IoT solution.
Because of the large number of devices, you decide to use three IoT Hubs, with the Device Provisioning Service.
Which is the best allocation policy you should use to distribute the device connections over the hubs?
Answers
Explanations
Click on the arrows to vote for the correct answer
A. B. C. D.Correct Answer: B.
Option A is incorrect because there is no allocation policy named “Hashed distribution”
Hashed distribution is applied by DPS in the case of Lowest latency, when more than one linked IoT hubs can provide the same latency.
Option B is CORRECT because in order to get the best performance and an actual real-time behavior, the best solution is to allocate the devices to the IoT Hub with the lowest latency.
The built-in “Lowest latency” allocation policy is the best choice here.
Option C is incorrect because with the Evenly weighted distribution (which is the default allocation policy) the requirement of real-time behavior will not be touched.
In the case of several IoT hubs, the solution should be optimized for latency.
Option D is incorrect because distribution by static configuration will not take into account the latency (real-time) requirement.
In addition, it doesn't make use of the DPS's built-in automatism.
Reference:
Given that the first stage of the environmental monitoring system consists of 10,000 sensor end-devices deployed all over three regions, and the goal is to connect them to an Azure IoT solution using three IoT Hubs, with the Device Provisioning Service. The challenge is to distribute the device connections over the hubs effectively.
The answer to this question depends on several factors, including the expected device traffic, the communication latency, and the distribution of devices across regions.
Let's take a closer look at the four possible allocation policies:
A. Hashed distribution: This policy involves distributing the devices based on a hash of the device ID or other device attributes. This policy is suitable when devices have no geographic or traffic-based patterns. However, if the devices are not evenly distributed or the traffic is not uniformly distributed, some hubs may become overloaded, and others may be underutilized.
B. Distribution by lowest latency: This policy involves allocating devices based on the hub with the lowest latency. This policy is useful when devices are geographically distributed and communication latency is a significant factor. However, this policy does not consider the current traffic on each hub and may result in overloading one hub while underutilizing others.
C. Evenly weighted distribution: This policy involves distributing the devices evenly across all hubs. This policy is suitable when there is no significant difference in the traffic or communication latency between the hubs. However, if the devices are not uniformly distributed, some hubs may become overloaded, and others may be underutilized.
D. Static configuration via enrollment list: This policy involves manually configuring each device to connect to a specific hub. This policy is suitable when there is a clear understanding of the distribution of devices and traffic, and the environment is not expected to change significantly.
Based on the given scenario, the best allocation policy to distribute the device connections over the hubs would be option A, Hashed distribution. It is because the devices are deployed all over three regions, and there is no indication of significant differences in traffic or communication latency between the hubs. Hashed distribution would ensure an even distribution of devices across the three hubs based on a hash of the device ID or other device attributes.
