Where to place Central Administration service?
This small topic has come up since my client asked as to why SharePoint Foundation Web Application service started on the server that was hosting Central Administration service a couple of days ago. Sometimes such a question is easy to be answered. Sometimes it would steal your hours just trying to find good reasons to justify against what you have proposed.
You might need to read the relevant topic: Determine your Web Front-end server
This article is going to clarify a few following concerns you might have when planning for SharePoint 2013 topology:
- Should SharePoint Foundation Web Application service and Central Administration service both run on an application server?
- Should SharePoint Foundation Web Application service and Central Administration service both run on a web front-end server?
Historically, the previous team proposed my client the traditional topology. That said, the topology contains two application servers and three web front-end servers. However, SharePoint Foundation Web Application service run on two application servers. Fundamentally these application servers also act as web front-end servers. Page requests from end-users to SharePoint are sent to application servers some future times. Recently, when the client bought a 3rd party product, they were required to pay totally 5 licenses because the topology had 5 web front-end servers. They came to us questioning why as proposed, the number of web front-ends were 5 instead of 3. If we had to turn off the SharePoint Foundation Web Application service, we needed to give them a reason.
After looking around the whole picture, I figured out that one of the farm solution contained custom timer job that was deployed to Central Administration web application (specifically to Job Definition page). With this purpose, the SharePoint Foundation Web Application service required to be started to handle the deployment (i.e. copying resources to the server). Moreover, the custom timer job used Microsoft.SharePoint.Administration.SPJobDefinition class. Such a job requires Central Administration service to be started on the server that the timer service processes the job. That’s why now the Central Administration service and SharePoint Foundation Web Application services are started on the same server.
Back to the questions at the beginning of this article, where are the two services supposed to be started? Well, it depends. This answer is the most common in the SharePoint world you uncomfortably have to hear all the time. It, however, is true in this case. Prior to the release of streamlined topology, Microsoft recommended Central Administration to be hosted in application server . If you don’t have custom timer job to be deployed to Central Administration web application, turn off SharePoint Foundation Web Application service in application server for the following reasons:
- When deploying farm solution, resources are not deployed to application server. This helps you save deployment time.
- Normal page request from end-users don’t hit application server, excepting requests to service applications (e.g. query search).
- Saving license of 3rd party product which is based on the number of web front-end servers.
The streamlined topology provides more flexibility to control performance, especially for low latency tier. In this type, Central Administration is recommended to be run on web front-end server. This should be fine if your organization doesn’t have strict policies on it.
If you decide to turn off SharePoint Foundation Web Application service, be aware of the fact that all web applications excepting the one for Central Administration will be unprovisioned.
If you turn on it on a Central Administration-hosted server, existing farm solutions and web application resources will be then deployed to that server. This take pretty much time and sometimes hang off unexpectedly if the server hosts many big web applications. The change may hurt your SharePoint configuration that would require recovery.