Google Cloud Professional Cloud Developer — Question 306

You work for an environmental agency in a large city. You are developing a new monitoring platform that will capture air quality readings from thousands of locations in the city. You want the air quality reading devices to send and receive their data payload to the newly created RESTful backend systems every minute by using a curl command. The backend systems are running in a single cloud region and are using Premium Tier networking. You need to connect the devices to the backend while minimizing the daily average latency, measured by using Time to First Byte (TTFB). How should you build this service?

Answer options

• A. 1. Run the air quality devices’ backends on Compute Engine VMs. 2. Create a weighted round robin routing policy on Cloud DNS. 3. Configure the air quality devices to connect by using this DNS.
• B. 1. Run the air quality devices’ backends on Compute Engine VMs. 2. Create a round robin routing policy on Cloud DNS for these Compute Engine VMs. 3. Configure the air quality devices to connect by using this DNS.
• C. 1. Run the air quality devices' backends in a managed instance group. 2. Create an external passthrough Network Load Balancer to connect to the managed instance group. 3. Configure a connection between the air quality devices and the Network Load Balancer.
• D. 1 Run the air quality devices' backends in a managed instance group. 2. Create an external Application Load Balancer, and connect it to the managed instance group. 3. Configure a connection between the air quality devices and the Application Load Balancer.

Correct answer: D

Explanation

Option D is correct because using a managed instance group with an external Application Load Balancer optimizes routing and reduces latency, which is crucial for minimizing TTFB. Other options, like using Compute Engine VMs with DNS routing (A and B), do not provide the same level of efficiency and scalability as the managed instance group with a load balancer. Option C, while using a managed instance group, employs a passthrough Load Balancer that may not optimize for HTTP traffic as effectively as an Application Load Balancer.