Exam Professional Cloud Network Engineer topic 1 question 83 discussion

Answer was clear, 3-tier setup required internal lb to application layer. https://cloud.google.com/load-balancing/docs/l7-internal Three-tier web services You can use Internal HTTP(S) Load Balancing to support traditional three-tier web services. The following example shows how you can use three types of Google Cloud load balancers to scale three tiers. At each tier, the load balancer type depends on your traffic type: Web tier: Traffic enters from the internet and is load balanced by using an external HTTP(S) load balancer. Application tier: The application tier is scaled by using a regional internal HTTP(S) load balancer. Database tier: The database tier is scaled by using an internal TCP/UDP load balancer.

This pretty much sums it (https://cloud.google.com/load-balancing/docs/l7-internal): Three-tier web services You can use internal Application Load Balancers to support traditional three-tier web services. The following example shows how you can use three types of Google Cloud load balancers to scale three tiers. At each tier, the load balancer type depends on your traffic type: Web tier: Traffic enters from the internet and is load balanced by using an external Application Load Balancer. Application tier: The application tier is scaled by using a regional internal Application Load Balancer. Database tier: The database tier is scaled by using an internal passthrough Network Load Balancer.

Since the web servers are already being load balanced by an external HTTP(S) load balancer, it makes sense to use an internal HTTP(S) load balancer to balance the application tier of servers, as it provides a way to keep traffic internal to the VPC network. Option A is incorrect as configuring a forwarding rule on the existing load balancer for the application tier would lead to mixing of external and internal traffic which is not a good practice. Option B is also incorrect because it suggests equal cost multi-path routing which is used for network routing rather than load balancing application tier servers. Option D is not feasible as a URL map is used to route traffic based on the URL path, rather than the server or backend group.

• C. Configure a new internal HTTP(S) load balancer for the application tier. Three-tier web services You can use Internal HTTP(S) Load Balancing to support traditional three-tier web services. The following example shows how you can use three types of Google Cloud load balancers to scale three tiers. At each tier, the load balancer type depends on your traffic type: PK: Just remember this topology. ******* • Web tier: Traffic enters from the internet and is load balanced by using an external HTTP(S) load balancer. • Application tier: The application tier is scaled by using a regional internal HTTP(S) load balancer. • Database tier: The database tier is scaled by using an internal TCP/UDP load balancer.

Answer - C https://cloud.google.com/load-balancing/docs/l7-internal#:~:text=Application%20tier%3A%20The%20application%20tier%20is%20scaled%20by%20using%20a%20regional%20internal%20HTTP(S)%20load%20balancer.

Answer D

c is right

forwarding rules route traffic to backends

Option C. Create new internal HTTP(S) Load Balancer

For example there is an external-facing web tier using an external HTTP(S) load balancer. This load balancer provides a single global IP address for users in San Francisco, Iowa, Singapore, and so on. The backends of the load balancer are spread across different regions, providing a high degree of failure independence and improved network latency for global users. These backends then access an internal load balancer in each region as the application or internal tier. Finally, the internal tier communicates with a database tier. The benefit of this 3-tier approach is that neither the database tier nor the application tier is exposed externally. This simplifies security and network pricing.

Please refer below link for more details. https://cloud.google.com/load-balancing/docs/l7-internal

C. Configure a new internal HTTP(S) load balancer for the application tier.

Answer is D. Url maps are used to direct traffic to the back ends and this would be where the application is located