Azure App Service Plan Selection for Custom Domains and Dedicated Instances

AZ-900 By islever Editorial Last updated

Describe Azure compute and networking services

Short answer

B The Basic tier supports custom domains, dedicated instances with 10GB storage per app, and load balancing while minimizing costs.

Question

Your developers have created 10 web applications that must be host on Azure.
You need to determine which Azure web tier plan to host the web apps. The web tier plan must meet the following requirements:
✑ The web apps will use custom domains.
✑ The web apps each require 10 GB of storage.
✑ The web apps must each run in dedicated compute instances.
✑ Load balancing between instances must be included.
✑ Costs must be minimized.
Which web tier plan should you use?
  1. Standard
  2. Basic Correct Answer
  3. Free
  4. Shared

Key Takeaways

The core trap is misinterpreting '10 web apps' as requiring 100GB total storage or assuming Basic limits instances per app; in reality, Basic supports unlimited apps with 10GB each and dedicated instances per app.

This question evaluates the selection of an Azure App Service Plan that balances dedicated compute instances, custom domain support, and cost efficiency. The correct choice is Basic, as it meets all technical requirements including load balancing while minimizing costs compared to Standard or higher tiers.

Common mistake: Many learners choose Standard because they incorrectly sum the storage (10 apps × 10GB = 100GB) and assume Basic's 50GB limit applies to the total rather than per instance, or they confuse instance scaling limits with app hosting limits.

Expert Analysis

Why the Answer Is Correct

The Basic tier of Azure App Service is the optimal choice because it satisfies all specific constraints at the lowest price point. It supports custom domains (unlike Free/Shared), provides dedicated compute instances for each web app (avoiding the noisy neighbor effect of Shared), and includes built-in network load balancing across those instances. Crucially, the Basic plan allocates 10GB of disk space per instance, which perfectly matches the requirement for each of the 10 separate web applications.

Why the Other Options Are Wrong

Free and Shared tiers do not support custom domains, eliminating options C and D immediately. While the Standard tier also meets all technical requirements, it is significantly more expensive than Basic. Since the prompt explicitly states that 'Costs must be minimized,' choosing Standard would violate this business constraint despite its technical adequacy. Some might argue Standard is needed for scale, but Basic allows up to 3 instances per app (scale-out) and sufficient storage per app, making it the cost-effective winner.

Community Comment Notes

Community discussion highlights the confusion around storage calculations. As user mahmoud_az noted, Standard has 50GB per instance, which seems ample, but ignores the cost minimization rule. User hkmomin pointed out that Standard supports 150GB total in examples, reinforcing that capacity isn't the bottleneck. Users like Harry28731 and Pradh clarified that the 10GB requirement is per web app, not a cumulative 100GB pool, confirming Basic's sufficiency. User sam7777 emphasized that Basic supports unlimited web apps, addressing fears about platform limits.

Exam Strategy

When selecting cloud services, always prioritize the lowest-cost option that meets all functional requirements. Do not over-provision based on cumulative sums if the service charges per unit (e.g., per instance); verify if limits apply per-unit or aggregate.

Frequently Asked Questions

Does Basic tier support custom domains?

Yes, the Basic tier fully supports custom domains, unlike Free and Shared tiers which require subdomains.

Is 10GB storage enough for 10 web apps in Basic?

Yes, the 10GB limit applies per instance/app, so each of the 10 apps gets its own 10GB allocation.

More AZ-900 FAQ →

Discussion 187 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 30 of 187

  1. mahmoud_az 👍 77
    the Answer is Standard : Standard tier support Custom Domains, Disk Space of 50GB wich is more than enough for the requested plan, and as long as they want to run each web app in a dedicated instance, that means we need 10 dedicated instances for the 10 web apps with a load-balancing service between them, the basic plan only support up to 3 dedicated instances. Finally the Standard plan has the lowest cost compared to Premuim and Isolated pricing tiers.
  2. hkmomin 👍 21
    It's confusing for sure but if I scroll down on the link and see under "Standard Service Plan" they have 50GB per instance. Example has 3 instance therefore 150 GB in total, based on that Standard should support.
  3. DartTrapdoor 👍 14
    Ten services need 10GB each whic his 100GB. I don't htink Standard is enough, I don't think any of the provided answers fit.
  4. angelrps 👍 14
    Why are there in general so many wrong answers in these tests? You cannot trust the solutions shown...
  5. Harry28731 👍 9
    Hi, Answer is unfortunately B. The wording of the question is bad though. Explanation : https://azure.microsoft.com/en-us/pricing/details/app-service/windows/#overview Customs domains : All but free 10G storage : Here is the confusion EACH web app requires 10GB does not mean 10 instances of ONE web app requires 10x10G = 100G or whatever. Its 10 DIFFERENT web apps. So BASIC is enough. Dedicated Compute Instances : Basic is enough. Load-balancing : Basic is enough. Don't mislead the scalability number. It works only if ONE specific web app is very consuming or you need high availability. Costs minimized : Here is the confusion. Nowhere it's written that all 10 web app must be in the same app service plan. You can have 10 app services for 10 web apps, or 2 app services fo 5 web apps each (standard). However I belive the question assumes 1 app service plan per web app, which one to choose ? This is why basic is preferred.
Show 25 more comments
  1. Pradh 👍 8
    FINALY AN END TO ALL THE ARGUMENTS !!!!!!!!!!!!!!!!!!!! YOU GUYS HAVE STRUGGLED A LOT FOR THE ANSWER . FINALLY YOU GET IT HERE :) Answer is B : BASIC Unlimited WebApps can be created per Azure App service Plan Custom Domain is supported in Basic Plan ..that too unlimited Compute instance type for each webApp is Dedicated with 10gb Storage..its not shared compute instance.That means 10 web app will have 10 dedicated compute instance of 10Gb each . Maximum instance that can be scaled out is 3 ....forget this point..not required in this question integrated load balancing is supported in basic Anybody who feels i am bluffing please go through this link.you will have to scroll down a bit to come to App service limits... ENJOY !! https://docs.microsoft.com/en-us/azure/azure-resource-manager/management/azure-subscription-service-limits#app-service-limits
  2. ilia_smirnov 👍 7
    How can i hold this information about limits and prices in my head?
  3. sam7777 👍 6
    The web apps will use custom domains. -- Basic is OK! The web apps each require 10 GB of storage. --Basic is OK! Do not mess it with the 10 VM and each VM 10 GB so total will be 100 GB-NO! We can create 10 instances and each 10 GB. So Basic is the best solution. The web apps must each run in dedicated compute instances. --We will create 10 instances in Basic :) Load balancing between instances must be included. -load balancing is included in basic tier. Costs must be minimized. -- Basic tier, 10 instances with 10 GB Reference: https://azure.microsoft.com/en-us/pricing/details/app-service/windows/ Please press ctrl+f and search for "Load balancing" :)
  4. hkmomin 👍 5
    Basic supports: Can host unlimited Web, mobile, or API apps - so this covers "Your developers have created 10 web applications that must be host on Azure" Basic supports custom domains which Web Apps require Basic also supports dedicated compute instances that web apps must each run on. Basic also supports Load balancing between instances (Built-in network load balancing support automatically distributes traffic across instances) What I don't understand is 10 GB per instance (3 for Basic) will be sufficient for 10 web apps that each require 10 GB of storage in Basic tier. Will that be 100GB of requirement in total and therefore you need to use Standard Plan (let's say one instance for each web app i.e. 10 instances which standard supports and 50 GB for each instance which is more than what's required).
  5. asans 👍 5 Answered B
    Basic tier meets all the requirements. The 3 instances that others are talking about is for scaling out, i.e. you can increase the VMs to a maximum of 3 should each Web app demand that. Off course, there is also the scale up, which is increasing the CPU, memory on one VM. ✑ The web apps will use custom domains. - Basic supports this ✑ The web apps each require 10 GB of storage. - Basic supports 10Gb per instance ✑ The web apps must each run in dedicated compute instances. - Basic supports this ✑ Load balancing between instances must be included. - Basic supports integrated LB ✑ Costs must be minimized. This link provides comprehensive details on the quotas for each Web tier. https://learn.microsoft.com/en-us/azure/azure-resource-manager/management/azure-subscription-service-limits#app-service-limits
  6. Dziurkas 👍 5
    "The storage limit is the total content size across all apps in the same App service plan. " - Doesn't it mean that 50GB is for all instances it this service plan?
  7. Moitjuh 👍 5
    "-We will create 10 instances in Basic :)" Only that is impossible as basic only supports up to three instances.
  8. Noble_Fart 👍 5
    Memorizing this table is ludacris. No one in the real world memorizes marketing charts.
  9. Ciupaz 👍 5
    Support Plans are not more in the exam.
  10. maxrudenk 👍 4
    answer is Basic. you could create 10 app service plans with limits per each 10gb storage. then we can host it on compute dedicated instances - App service. App service working on service plan. And Basic plan provides dedicated compute instance type. Also we could create load balancer on basic plan but we can't enable autoscaling. But we only need load balancing according to requirements. https://learn.microsoft.com/en-us/azure/azure-resource-manager/management/azure-subscription-service-limits Basic Plan: - The actual number of apps that you can host on these machines depends on the activity of the apps, the size of the machine instances, and the corresponding resource utilization = 100 App service plans per resource group - The storage limit is the total content size across all apps in the same App service plan. The total content size of all apps across all App service plans in a single resource group and region cannot exceed 500 GB. The file system quota for App Service hosted apps is determined by the aggregate of App Service plans created in a region and resource group = 10 GB for App service plan
  11. Ariel235788 👍 4 Answered A
    A. Standard Here's why: Custom Domains: The Standard plan supports custom domains. Storage: The Standard plan offers 50 GB of storage, which can accommodate 10 GB per web app. Dedicated Compute Instances: The Standard plan provides dedicated compute instances for each web app, unlike the Free or Shared tiers that share resources. Load Balancing: The Standard plan includes built-in load balancing across instances. Cost Minimization: The Standard plan is more cost-effective than the Premium plan, while still meeting all the necessary requirements.
  12. Sharneh 👍 4
    The Answer is Basic: don't get confused with No of Instance requirement vs Maximum Supported Instance for scalability. Basic Tier supports manual Scalability up to 3 instance for a particular web app hosted on it. We do not have a scalability requirement so we just need to run 1 instance of each web app and Basic can support that.
  13. aguinaga 👍 4
    Answer D: Non of the above - 10 Web Apps x 10GB required space for each = 100GB They would would near a Premier plan, which isn't even in the answer choices.
  14. Dharun_19 👍 3
    The requirements specify that the web apps need custom domains, each requires 10 GB of storage, must run in dedicated compute instances, and need load balancing between instances, while also minimizing costs. Here's a breakdown of the options: - Free: Does not support custom domains, has limited storage, does not provide dedicated compute instances, and lacks load balancing. - Shared: Supports custom domains but does not provide dedicated compute instances and lacks load balancing. - Basic: Supports custom domains and provides dedicated compute instances, but does not include load balancing. - Standard: Supports custom domains, provides dedicated compute instances, includes load balancing, and offers more storage. Given the requirements, the Standard tier plan is the only option that meets all the requirements: A. Standard
  15. MGJG 👍 3
    Your developers have created 10 web applications that must be host on Azure. -> Free,shared,basic, standard and premium do that. You need to determine which Azure web tier plan to host the web apps. The web tier plan must meet the following requirements: The web apps will use custom domains. ->shared,basic, standard and premium do that. The web apps each require 10 GB of storage. ->Your developers have created 10 web applications that each require 10 GB of storage. 100 Gbs.. premium do that The web apps must each run in dedicated compute instances. -> dedicated Compute Type .. premium do that Load balancing between instances must be included. -> Integrated load balancer .. premium do that Costs must be minimized. https://docs.microsoft.com/en-us/azure/azure-resource-manager/management/azure-subscription-service-limits#app-service-limits
  16. Kanatius 👍 3
    The Basic plan supports 10GB storage for $0.018/hour and Standard Supports 50GB for $0.095/hour. In one Basic Plan we can put only 1 app, so we need 10 basic plans = a total of $0.18/hour In one Standard Plan we can put 5 apps, so we need 2 standards plans = a total of 0.19/hours Max number of instances in the plans means REPLICATION, how many times you can replicate your app to get scalability. You cannot put 3 different apps each using 10GB on basic plan, but 1 app using 10 GB replicated in 3 instances, instead.
  17. Meesquared 👍 3 Answered A
    Key Points from Requirements: ✅ Custom domains → Requires at least Basic ✅ 10 GB x 10 apps storage = 100GB → Standard ✅ Dedicated compute instances → Basic or Standard ✅ Load balancing → Only Standard or Premium tiers ✅ Minimize cost → Choose the cheapest that meets requirements = Standard 👉 Answer: Standard (A)
  18. packl74 👍 3
    Standard and basic not adjust because you have 10 web app and need 10 GB each one, for that reazon the total of storage is 10 appweb x 10 GB store = 100 GB total storage and in standard tier the limit is 50Gb storage?????? I think something is missing in the question
  19. Stanzin 👍 3
    I don't think the 10GB of space is shared b/w all web app instances, i.e. if you have 10 different web apps, Standard tier will get you 50gigs each, Basic will get you 10gigs each and so on.
  20. ssddd9156 👍 3 Answered A
    As thy require 10 instances but basic supports max 3 instance so i think standard should be ans.I am also preparing for az-900 let see how much helpful a public community thread is.
  21. Kordrakka 👍 3 Answered A
    https://azure.microsoft.com/en-us/pricing/details/app-service/windows/ Basic's Maximum instances is Up to 3. Question requires 10 which Standard covers.
  22. examtopics6969 👍 3
    I think you confuse app with app instance.
  23. ancity 👍 2
    the Basic web tier plan can support 10 web applications. Let's take a closer look at the details: The Basic web tier plan has the following limits: Number of web apps: 10 Number of small (shared) instances: 3 Number of medium (dedicated) instances: 3 Number of large (dedicated) instances: 3 So the Basic plan can indeed support up to 10 web apps, with the limitation that you can only have up to 3 dedicated instances. For 10 web apps, each requiring dedicated compute instances, the Basic plan may not be sufficient. The Standard web tier plan would be a better choice, as it has higher limits: Number of web apps: 100 Number of small, medium, and large (dedicated) instances: 10 each The Standard plan would provide more flexibility to scale out the 10 web apps and ensure they each run in a dedicated compute instance. Therefore, the correct answer should be: A. Standard
  24. jakerson 👍 2
    A. Standard: The Standard tier plan provides features such as custom domains, dedicated compute instances, 10 GB of storage per app, and load balancing between instances. It offers the necessary capabilities to fulfill all the requirements mentioned. B. Basic: The Basic tier plan does not provide dedicated compute instances or load balancing between instances, which are required in this case. C. Free: The Free tier plan does not offer the necessary features for hosting the web apps, such as custom domains, dedicated compute instances, or sufficient storage. D. Shared: The Shared tier plan does not provide dedicated compute instances or load balancing, and it may not offer the required storage capacity for each web app. Therefore, the most suitable web tier plan that satisfies all the given requirements while minimizing costs would be the "Standard" tier plan.
  25. Pieter1101 👍 2 Answered A
    The correct answer is A. Standard ✅ Here’s why the Standard tier is the best fit: 🔍 Requirements Breakdown - Custom Domains: Supported by Basic and Standard, but not Free or Shared - 10 GB Storage per App: Basic offers 10 GB total per plan—not per app—while Standard provides 50 GB per plan, which is more scalable - Dedicated Compute Instances: Only Basic and Standard tiers offer dedicated compute; Free and Shared use shared infrastructure - Load Balancing: Included in the Standard tier by default; Basic does not include built-in load balancing - Cost Minimization: While Basic is cheaper, it fails to meet all requirements. Standard is the lowest-cost tier that satisfies every condition So even though Basic might seem tempting for cost reasons, it falls short on storage and load balancing. Standard is the most cost-effective option that ticks every box.

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