Hello

I currently have one application pool in my SharePoint environment that holds 12 SharePoint Web Applications.  I am following the Microsoft standards by having one app pool and all the web applications running in it.

However, when I create a new web application in the application pool, I find that during the creation process the existing web applications in the app pool become unresponsive - I have monitoring software that polls my SharePoint web apps and when the new web app is being created I get feedback from my monitoring software saying that my other web apps are not contactable or available.

My two questions are

1 - Is it best to have all web apps in one app pool?  I have 2 wfe servers, an app server and a sql server.

2 - how can I stop this from happening?  Do the web applications restart when a new web app is created? 

THanks

Martin

1 - It is not a best practice to have all web apps in one app pool. This is for precise reason that app pool restart/hung will cause all web apps to restart/hung at once. Also app pool acts a logical and security boundary.

2 - Ideally you should have separate app pools for separate web apps. You can use same/different service account to create another web app pool. As long as its a separate identity, it will not cause restart of other web apps.

However this will increase the resource usage on the server. Each app pool cause a separate overload of ~100/200 MB on its own (noting that incoming request load remains same per web app).

Hope this helps.

Thanks for that.  Why would Microsoft say that it is good practice to put all of your web apps in once application pool then?

So are the web apps restarting because I am creating a new web application in the same pool as existing web applications?

I'm not sure where Microsoft said that it is good practice to put all of web apps in one application pool. In terms of SP2013, MS recommends use of host named site collections which allows multiple FQDNs within one single web app. However again its one app pool per web app.

Your web apps are restarting most probably because application pool is recycled during creation of web app.

hope this

1. Microsoft recommendation is 10 application pools per web server. 

https://social.technet.microsoft.com/Forums/office/en-US/c2de887a-25dd-4554-9181-f4ab1093d8d1/best-practices-for-web-applications-and-app-pools-in-2013?forum=sharepointgeneral

https://technet.microsoft.com/en-us/library/cc262787.aspx?f=255&MSPPError=-2147217396#WebApplication

2. When new web application is created the application pool is recycled. All existing application using the application will be down during that time.

Hi,

I don't think is currently possible to have a no downtime architecture model with Sharepoint 2013. 

A possible way to reduce the deployment downtime considerably is to have a multi-front-end farm and upgrade them one by one and make the switch between them using a load-balancer.

This will mimic the "no downtime" method.

Having a single application pool for multiple Web applications indeed reduces the number of w3wp.exe processes but when a new webapp is created the pool will recycle.

To conclude, minimize downtime by using separate App pools, multi web-front-end farm and load balancer.

In the near future Sharepoint 2016 claims to have no downtime deployments.

Hope this helps, 

Regards,

R

• Edited by Razvan Stefan 23 hours 9 minutes ago

Hi Razvan,

Thanks for your reply.  What do you mean by having a "multi-front-end farm" and then upgrading them one by one?  I am taking about creating new web applications, not upgrading them.

I created a new web app just before using a new application pool and I still had an alert from my monitoring software.