With the release of Sitecore 9.0.2 rev. 180604 (Update 2), Sitecore has provided a new application called Update Center.
Yes, the new application and as the name says, it allows you to find, download, install, and manage updates and hotfixes for the Sitecore platform and Sitecore modules. This update center accesses a package management service for getting information about the updates available. You would have two options for the package management service. Once is to use provided by Sitecore, or you can install and provide a service yourself. Apart from this, using the Update Center, you can install updates from a package in the file system as well.
When you open the Update Center window from the Sitecore Dashboard, it looks like below given screen.
The Update Center provides three options (left pane):
- Updates – By clicking this you can see a list of available updates from the package management service.
- Installed modules – By clicking this you can see a list of already installed modules.
- Install custom update – By clicking this you can select a package from the file system to install it in Sitecore.
When you select any update package from the list of available updates, the Update Center shows you the following information about the package, and those are obtained from package metadata.
- Version Number
- Information about breaking changes
- A link to the release note for the packages.
- Pre-and post-installation steps.
The Update Center provides a button to toggle between “Enter update mode/Exit update mode” while installing the updates.
The Ready to install dialog provided during the update installation process provides a set of options which you can use to customize the install/update module process. This Read to install dialog first notifies that the Sitecore will switch to Update Mode during the installation of the update file and will remain in Update Mode until the mode is disabled manually from the Update Manager application.
Begin in Update Mode allows you to modify your Sitecore installation after completing the update. All installed modules and other parts of Sitecore are deactivated while being in Update Mode.
The most important functionality from Update Center is the use of Update Mode during installing the updates.
The Sitecore configuration is divided into four different layers:
While installing updates, the Update Center turns all the configuration layers off except the Sitecore layer. On top of that, it adds and activates a layer called Update, and creates a temporary folder called Update in App_Config folder.
This update folder contains the following three configuration files:
- DisableXDB.config – this file disables Sitecore xDB and Sitecore xDB Tracking
- DataFolder.config – this file enables the Data folder. This is necessary because Sitecore does not work without access to the license.xml file.
- Layers.config.orig – this file is a back up of the original Layers.config file before Sitecore has entered in update mode
If we check the Layers.config in the Sitecore, when it is in the update mode, we can see that only Sitecore and Update layer elements are on and other layers are in the off mode.
When Sitecore is in the update mode, it runs as platform-only. This provides more stability while the update takes place. When Sitecore exits update mode, it restores the Layers.config file from Update folder an deletes the temporary Update folder.
Update Center Configuration
Sitecore has made this Update Center configurable where we can set the location of packages via PackageManagementServiceUrl setting in App_Config/ConnectionStrings.config file.
The default setting connects to Sitecore Package management:
<add name=”PackageManagementServiceUrl” connectionString=”https://updatecenter.cloud.sitecore.net/” />
You can point to a local instance of the package management service, by changing this above connection string value.
I’ll keep updated as I’ll learn more about this.