Upgrading a Deployed Solution

One of the problems SharePoint developers encountered in past versions of the product is that it was difficult to update solutions once they had been deployed to the farm. If a feature deploys elements like content types or list instances when it is activated, how do these get updated if they are altered in a later version? In 2010, SharePoint introduced a new set of configuration options designed to make these upgrades, if not exactly easy, at least manageable.

Feature Versioning

The key to upgrading a solution package successfully is a new technique called feature versioning. Each feature in a solution file has an associated feature.xml file. This file identifies all of the parameters and components of the feature. New markup options in SharePoint 2010 allow the feature to be given a version number and have a set of upgrade actions defined. When the solution is upgraded, this information is used to perform any actions needed to upgrade existing content that was created based on a previous version of the solution.