Background: Our server beyond the recommended limit for SP2013 (Software Boundaries and Limits) on the number of Application Pools per server (10). I'm wondering if that is what is causing a noticeable lag, especially in Central Administration. I already fixed a time-out issue by extending the "Shutdown Time Limit" in IIS, but would like also to optimize the performance.
Question: I'd like several of the SP Web Applications grouped to share an AppPool, so I have 3 AppPools instead more than 10. By order of preference (1) How do I do this in Central Administration, (2) in PowerShell, (3) or in IIS (most likely not the recommended practice)? What is the best practice?
Update (6/29/17): I actually ended up deleted 5 unused Web Apps (7 left, including Central Admin). That didn't really fix the lag issue on the WFE side, but this these two Powershell commands seem to:
PS> Set-SPEnterpriseSearchService -PerformanceLevel PartlyReduced
PS> Restart-Service SPSearchHostController
Credit: https://sharepoint.stackexchange.com/questions/125174/reduce-noderunner-exe-impact
Each time you create a web application in sharepoint, you are invited to create a new application pool, via central admin.
Each time you create a service application in sharepoint (search, user profile, managed metadata), you are invited to create a new application pool, via central admin.
If you want to re assign the app pool, you can navigate to central admin > Manage service application > Select the service > Click properties in the ribbon > Change the applicaiton pool.
As for powershell code to create app pool or re assign services, i do not have them.
From IIS side you shall only create application pool in case you want to re assign existing services applicaitons to new app pool.
As for your central admninistration slowness, may you share your existing machine specs ? For a developer VM, I have run my VM fast with 4vcpu / 24 gb ram / 8 gb for sql (limit the sql instance to 8gb) / set the search to minimal performance (there are powershell for this)