Installing and Upgrading Applications in ServiceNow
Understanding Installing and Upgrading Applications in ServiceNow
Installing and upgrading applications is a fundamental aspect of managing applications within the ServiceNow platform. For the Certified Application Developer (CAD) exam, this topic is critical because it tests your understanding of how applications are distributed, installed, maintained, and upgraded across ServiceNow instances.
Why Is This Important?
ServiceNow environments are dynamic and constantly evolving. Organizations rely on both built-in and custom applications to automate workflows, manage IT services, and drive business outcomes. Understanding how to properly install and upgrade applications ensures:
- System stability: Improperly installed or upgraded applications can break existing functionality, cause data loss, or introduce conflicts.
- Version control: Keeping applications up to date ensures access to the latest features, bug fixes, and security patches.
- Compliance and governance: Organizations need structured processes for deploying changes to production environments.
- Developer productivity: Knowing the correct procedures allows developers to efficiently move applications between instances.
What Is It?
Installing and upgrading applications in ServiceNow refers to the process of deploying new applications or updating existing ones within a ServiceNow instance. Applications can come from several sources:
1. ServiceNow Store: The official marketplace where both ServiceNow and third-party vendors publish applications. These applications are certified and tested for compatibility.
2. Update Sets: XML files that capture configuration changes made in one instance and can be transferred to another instance.
3. Source Control (Git): Applications linked to a source control repository can be installed or updated by pulling changes from the repository.
4. Application Repository: ServiceNow maintains an application repository that tracks published applications and their versions across instances within the same company.
How It Works
Installing Applications from the ServiceNow Store:
- Navigate to System Applications > All Available Applications > All.
- Browse or search for the desired application in the ServiceNow Store.
- Click Install to download and install the application to your instance.
- The application and its dependencies are automatically installed.
- A system administrator role (admin) is typically required to install store applications.
Installing Applications via the Application Repository:
- When a developer publishes an application from a development instance, it is stored in the application repository.
- On the target instance, navigate to System Applications > All Available Applications > All.
- Applications available from the repository will appear and can be installed directly.
- This is the standard mechanism for moving scoped applications between instances in the same company.
Installing Applications via Update Sets:
- Export the update set from the source instance as an XML file.
- On the target instance, navigate to System Update Sets > Retrieved Update Sets.
- Upload the XML file and preview the update set to identify conflicts.
- Commit the update set to apply the changes.
- Note: Update sets are primarily used for configuration changes and are not the recommended method for installing scoped applications.
Installing Applications via Source Control:
- Link an application to a Git repository using Studio or Source Control integration.
- On the target instance, import the application by connecting to the same repository and applying the desired branch or tag.
- This approach supports modern DevOps practices and is increasingly recommended by ServiceNow.
Upgrading Applications:
- When a newer version of an installed application is available (from the Store or application repository), a notification or indicator appears.
- Navigate to System Applications > All Available Applications > All or the Installed tab.
- Click Update next to the application to upgrade to the latest version.
- ServiceNow handles dependency checks and version compatibility during the upgrade process.
- It is important to test upgrades in a sub-production instance before applying them to production.
- Customizations made to store applications may be overwritten during upgrades, so it is best practice to use separate custom applications or update sets for customizations rather than modifying store application files directly.
Key Concepts to Remember:
- Scoped Applications have their own application scope, which protects their artifacts from being modified by other applications. This is central to how applications are installed and upgraded.
- Application Dependencies: Some applications depend on others. ServiceNow checks for and installs dependencies automatically when possible.
- Publishing Applications: Developers publish applications to the application repository using Studio. The Publish action makes the application available for installation on other instances in the same company.
- Versioning: Each published application has a version number (e.g., 1.0.0). When you upgrade, you move from one version to a higher version. Proper versioning is essential for tracking changes.
- Team Development: In environments using Team Development, applications can be pushed or pulled between instances. This is another mechanism related to installing and syncing application changes.
- System Plugins: Some ServiceNow features are delivered as plugins that must be activated. Activating a plugin is similar to installing an application and is done via System Definition > Plugins. Plugins are managed by ServiceNow and are upgraded automatically during platform upgrades.
Exam Tips: Answering Questions on Installing and Upgrading Applications
1. Know the primary methods: Be clear about the differences between installing from the ServiceNow Store, the application repository, update sets, and source control. Exam questions may present scenarios and ask you to choose the correct method.
2. Understand the role of the application repository: This is the recommended way to move scoped applications between instances. If a question asks about deploying a custom scoped application from development to test or production, the answer is typically publish to the application repository and install from there.
3. Differentiate between update sets and scoped application deployment: Update sets are used for global scope configuration changes. Scoped applications should be published and installed via the application repository or source control. This is a common exam trap.
4. Remember the testing best practice: Always test upgrades in a sub-production instance before deploying to production. If a question mentions best practices for upgrading, this is almost always the correct answer.
5. Watch for questions about customizations during upgrades: Customizations to store applications can be lost during upgrades. The best practice is to avoid directly modifying store application files. Instead, extend functionality in a separate scoped application.
6. Know about plugins vs. applications: Plugins are activated (not installed in the traditional sense) and are upgraded as part of the platform upgrade. Applications from the store are installed and upgraded independently.
7. Pay attention to roles: Installing applications typically requires the admin role. Some questions may test whether a specific role can perform installations.
8. Understand dependencies: If an application depends on another, ServiceNow will attempt to resolve the dependency automatically. Know that dependencies are checked during installation.
9. Source control integration: Questions may ask about how to use Git with ServiceNow applications. Remember that Studio provides the interface for linking to repositories, and branches/tags are used for version management.
10. Elimination strategy: When in doubt, eliminate answers that suggest manual or ad-hoc methods (like copying XML files manually or making direct database changes). ServiceNow emphasizes structured, platform-supported methods for application lifecycle management.
By mastering these concepts and tips, you will be well-prepared to handle any CAD exam question related to installing and upgrading applications in ServiceNow.