Sizing/Planning and compatibility – SP 2013 OOTB Workflow & Workflow Manager

As we prepare for our upcoming SharePoint 2013 migration, I asked Keith in our office to look into how to best size our Workflow platform and the new Workflow Manager and to determine the correct placement for the Workflow Manager (key learning is it can be installed on your SharePoint APP Server, unlike the OWA role in 2013).

Can the new Workflow Manager be installed on a SharePoint App Server?

Before considering server deployment targets, it’s important to understand the new workflow architecture in SP 2013. A new option exists when you build a workflow for SharePoint Server 2013. This option is called Platform Type. The figure shows the Platform Type option when you are creating a new workflow by using SharePoint Designer 2013.

Figure: SharePoint 2013 includes three workflow platform options.

The only platform available when you first install SharePoint Server 2013 is the SharePoint 2010 Workflow platform. The SharePoint 2013 Workflow platform and the Project Server platform require additional steps. The three workflow platforms are outlined in the following table.

Workflow Platform types available in SharePoint Server 2013

Reference: http://technet.microsoft.com/en-us/library/jj658588%28v=office.15%29

What this boils down to: if you are running OOTB SharePoint 2013, it will have the SharePoint 2010 Workflow model built in, which runs on Windows Workflow Foundation 3 and “lives” in the OWSTIMER.EXE process just as it did on 2010. Same topology rules apply as in 2010. If we want to leverage the new 2013 Workflow engine, we need to install the Workflow Manager from http://go.microsoft.com/fwlink/p/?LinkID=252092

Instructions for Installing and Configuring Workflow Manager:
http://technet.microsoft.com/en-us/library/jj193478.aspx

So, now we understand the flavours, let’s examine the base question which is essentially – could I/should I install the Workflow Manager on just the App Server in a WFE + App server environment, to reduce load on WFE’s.

Can Workflow Manager be installed on App Server? Yes

1. On http://technet.microsoft.com/en-us/library/cc262485%28v=office.15%29 it’s indicated that “You can install Workflow Manager on a dedicated computer.”
2. On the topology chart at http://zoom.it/GvRG#full it displays configurations (e.g. “Two-Tier”) where it’s all in one.
3. The Workflow Manager is abstracted from SharePoint and really is more of an Azure thing. It creates an IIS site on the server(s) where it’s installed but doesn’t really care what else is on that server.

Is there any benefit to isolating the Workflow Manager to the App Server?

Same concepts that would apply to standard SP2010 workflow topology considerations apply: if you are expecting heavy lifting, then offsetting the Workflow Manager to an App server is prudent.  For “high-availability” mode you would need involve Service Bus and it requires 3 servers running Workflow Manager, in their own internal “farm” network.