What is a Content Type Hub?
A Content Type Hub is pretty much a site collection that has the Content Type Syndication Hub site collection feature activated. Content types created in that site collection can be published to all site collection in the farm. This is useful when you want to have the same content type through all your site collections without having to go in each site collection and create the same content type. Also, it is easy to update the content type and push modifications to all site collections.
How to publish a Content Type from the Hub
It is easy to publish content types or push modifications that has been done on a content type. Simply go to the Content Type Hub site collection of your SharePoint version (listed above) and create your content type. Then go in the content type settings and click on Manage publishing for this content type. If this is a new content type, select publish and press OK. If you are making modifications on an existing content type, select Republish and press OK. Your content type will not be copied right away after publishing the content type. SharePoint uses timer jobs that will eventually copy the content type to all site collections. If you want the content type to be copied right away, you will need to run the two following timer jobs in central administration :
- Content Type Hub
- Content Type Subscriber : there is one of this timer job for each web app, so run the job of the web app where the site collection, that you want to get the content type, resides.
There is no way to run the timer jobs in Office 365, so you will have to wait for the timer jobs to execute themselves (worst case 1 hour).
Does Sharegate auto-publish migrated content types to the Content Type Hub?
Sharegate will only migrate the content types. It is possible to migrate content type from a site collection to a content type hub, for example, but Sharegate does not publish content types. Publishing the content types will require manual operations from the user.
Migrating a site collection with a content type from a Content Type Hub.
When publishing a content type from the Hub, the content type is physically copied to the site collection. So when copying the site collection to another web app, the content type will be copied. However, if the destination has a Content Type Hub containing a content type with the same name, we will not reattach to the content type from the Hub. This is because the Content Type Hub works with the content type ID and Sharegate do not preserve those IDs.
Publishing a content type that already exists in a site collection.
There is a mechanism in SharePoint that check if there is already a content type with that name in of the subscriber site collections. If there is one, SharePoint do not publish the content type on that site collection. Since the content type is not copied to the site collection, the publish is not done on that site collection. That is explain by the fact that the publish is made using the content type ID and since it is not the same content type, it is not modified.
What if we migrate a content type to a site collection that subscribes to a Content Type Hub and this content type already exists and is pulled from the Hub.
Sharegate only merge content types. That means that the content type ID will not be modified. However, content type from the Hub are Read-Only by default. When merging to a Read-Only content type, we skip informations about the content type. You can remove the Read-Only constraint on the content type at destination, then do a merge to get information from the content type at the source. The content type ID is kept so on the next publish on the Hub, the content type will be overwritten by the content type on the Hub. Be assured that removing the Read-Only constraint does not detach the content type from the Content Type Hub.
What if we migrate a content type to a Content Type Hub?
Once again, we can only merge. The content type on the Hub is not Read-Only so we will pull informations from the source content type but we will keep the ID intact. You will need to republish manually the content type if you want to apply this change to all subscriber site collections.
Can I migrate a Content Type Hub?
Yes. But there is some manual operations that will be required for the Content Type Hub to be working. First, it is recommended to put the Content Type Hub on a separate web application. So you will need to create a new web application first. You can copy the site collection with Sharegate to the new web application. We do not activate the Content Type Syndication Hub feature, so that will need to be activated manually. A Managed Metadata Service will need to be created in the Central Administration. This service is needed to publish content types to site collections.
Important informations on Content Type Hub
- Content types in a site collection that is from the Content Type Hub will be read-only by default
- Content Type Hubs are only available in SP2010, SP2013, SP2016 and Office 365
- Content type from the Content Type Hub are pretty much the same so there should not be a problem within Sharegate
- A republish of the Content Type is needed after modifications, otherwise changes will not be pushed to site collections