Max Apps per App Service Plan SKU Guidance Needs Updating

[zack4485]

The guidance found on this page under the Should I put an app in a new plan or an existing plan? heading appears to ignore the per-app/high-density scaling feature...

Specifically the guidance expresses a limit on the number of applications that can be hosted on an app service plan dependent upon the ASP SKU. That guidance was correct prior to the release of the per-app/high-density scaling feature, but with the availability of this feature the guidance really should be expressed either as:

• Maximum number of apps per app service instance/worker -or-
• Maximum number of apps per app service plan SKU when per-app/high-density scaling is disabled

The documentation for per-app/high-density scaling focuses myopically on the scenario of collocating lightweight and heavyweight applications within the same ASP and doesn't account for a scenario where a customer has lots of apps having identical memory requirements; in the latter scenario a customer might realistically be able to exceed the "max apps per plan" guidance without negative consequences...

Here's an example:

1. Suppose a SaaS provider operates a multi-tenant application that requires 1GB of RAM per tenant
2. Suppose the SaaS provider selects the P1mv3 SKU (16GB of RAM)
3. Suppose the SaaS provider deploys an ASP with minimum instance count = 3
4. Suppose the SaaS provider deploys each app with SiteConfig.NumberOfWorkers = 2

Node1	Node2	Node3
1	1
	2	2
3		3
4	4
	5	5
6		6
7	7
	8	8
9		9
10	10
	11	11
12		12
13	13
	14	14
15		15
16	16
	17	17
18		18
19	19
	20	20
21		21
22	22
	23	23
24		24

In the above example the SaaS provider could deploy approximately 24 apps to such an ASP and each instance would only host 16 apps.

This is within what I believe is the spirit of the guidance but unfortunately, as written, the guidance would appear to mean such a deployment would be unsupported.

I've filed an issue on the high-density scaling documentation as well for the same reason; they should probably be triaged together. https://github.com/MicrosoftDocs/azure-docs/issues/120712

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Document Details

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• ID: 09a9696e-10fd-a74e-4957-0d7ed9ef5a0f
• Version Independent ID: dad3cbd5-b2d0-9cc4-261f-97b95cf811c6
• Content: App Service plans - Azure App Service
• Content Source: articles/app-service/overview-hosting-plans.md
• Service: app-service
• GitHub Login: @msangapu-msft
• Microsoft Alias: msangapu

[ManoharLakkoju-MSFT]

@zack4485 Thanks for your feedback! We will investigate and update as appropriate.

[Venkateshdodda-MSFT]

@zack4485 I have assigned this to content author @msangapu-msft to review and shared the valuable feedback on this.

[msangapu-msft]

We've added this to our backlog to review and update as necessary. #please-close