SharePoint MinRole - IIS Server AppPools

Question

I have just installed a new SharePoint 2016 environment using MinRoles like this.

1. [WebFronEnd & Cache]
2. [Application & Search]
3. [Database]

I have now created the very first web applications and sites and just reviewed the IIS Manager.

I was now wondering that also on the Application & Search role server the IIS-Pools and Sites have been created. I would have expected that they would only been created on the web-front end?

Could you please help me to get an better understanding why this is that way?

Answer 1

It is a good practice to also start the "Microsoft SharePoint Foundation Web Application" on application servers of the SharePoint farm. For example, a WebApplication-scoped solution will only deploy it's code only to a server where this service is started. The code might be needed on backend-servers and starting the service will ensure that. Another thing might be the ability to crawl WebApplications directly on the SearchServer by redirecting the crawler via HOSTS-file.

Microsoft has taken this behavior into account when building the minrole service-assignment.

Answer 2

This is expected behavior due to fact that "Microsoft SharePoint Foundation web Application" is part of both min role ('WebFronEnd & Cache' & 'Application & Search'). This service is automatically provisioned on both server which basically provisioned the Web application on both servers.

Why we need this, there are many back end timer services which required foundation web services. if you want to crawl backend server rather to crawl via Web front to reduce load on WFE, this service is required. Also, if you have to deploy a solution farm wide, this service required otherwise it failed. Or if you have Nintex workflow in your farm then u need this service on app servers otherwise workflow will throw errors. these are just few examples.