Sonntag, 4. Januar 2015

The anatomy of Office 365 Groups

Microsoft released a new feature called „Groups“. This article is about the anatomy of this feature, the architecture and the structures in the backend.
For common information and the ideas behind Groups check out this link:

Create a Group

Groups are actually only available in O365 using Outlook online. You can create a new Group by navigating to Outlook online “Group” tab and press “Create Group”:

This starts a dialog for to collect the needed information’s like Name, Privacy settings etc.
Default setting for Groups in O365 allows everyone to start a new Group. To change this we need PowerShell:
Connect to your O365 Tenant -> Exchange Online:
Then we can use this commands:
-          to disable Groups: Set-OwaMailboxPolicy -Identity\OwaMailboxPolicy-Default -GroupCreationEnabled $false
-          to enable Groups: Set-OwaMailboxPolicy –Identity\OwaMailboxPolicy-Default -GroupCreationEnabled $true

Groups architecture

After a new Group is created you see a new tab in Outlook online for this Group. For every Group we have an overview page like this:

We can see all the conversations for this Group. Based on the “subscribe setting” during the create dialog every post in a conversation will result in an Email to all members of this Group. Insofar we are still in Exchange online.
We can also see that per Group we have elements like Calendar and Files. Calendar is also based in Exchange online but Files are based in SharePoint online. Navigating to the Files of a Group redirects to the MySite of the user:

But the MySite host is not where the documents a stored. For every Group a hidden Site Collection is created in SharePoint online. We cannot see this Site Collection in SharePoint online administration, but you see the URL for example in the hover-panel of a document:

So in my example the URL of the hidden Site Collection associated to my Group is:
We cannot access this Site Collection. Navigation to this URL automatically redirects us to the Group Files overview page located in users MySite. This is also true for every other Sub-URL. So if we try to go to _layouts/15/seetings.aspx or to the _layouts/15/listedit.aspx to change Document Library Setting etc. we are redirected to the Group Files overview page located in users MySite. The only way to manipulate settings is using SharePoint Designer or SharePoint Client Browser. Opening the Site in SharePoint Designer looks like this:

As we see we can manipulated some settings using SharePoint Designer. BUT this is not supported and can only be useful as part of testing and troubleshooting scenarios!
Last component is Azure AD. As we see so far Groups are using Exchange online and SharePoint online. So question is what kind of objects are Groups – and the answer is that Groups are Azure AD objects.

As you can see we have a Groups tab in Azure AD and there we can find a list of all Groups. Navigating to a Group we have several settings and information’s, amongst other things we can see the Objekt-ID which is the unique identifier for the Group.
So Groups are not a SharePoint online thing and also not an Exchange- or Outlook online thing. Groups are located in Windows Azure AD and Groups are a Office 365 feature. Because of this: Groups can easily be used in all features belonging to Office 365 and the underlying Windows Azure AD. The article I mentioned at the start of this post talks about “…In upcoming phases, we will add Yammer and Lync to the Groups experience to help you do even more”. Now we understand that this can easily be done based on the underlying Azure AD.


4 Kommentare:

  1. Hi Nicki - thanks for the post. I was wondering if you know what are the optiosn for getting the member in a group programmatically, (via REST or Powershell)?

    Mark Jones

  2. Hi, yes, you can use the REST API to do this. The API works also on this special / hidden SiteCollections

  3. Hi Nick - great post. Do you have any info or references to how Yammer will be added to Office 365 groups?