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Microsoft Fabric provides multiple ways to add and manage libraries when developing with Spark. With the recent release of Quick mode in Environments, Fabric now offers a more flexible, performance-oriented approach to library management. Choosing the right strategy can reduce publish time, speed up notebook startup, and improve production stability.
This guide explains when to use each option and how to combine them effectively.
Figure: Screenshot of the Environment interface showing libraries being added through quick mode and full mode.
Adding Libraries in Microsoft Fabric Environments
Microsoft Fabric Environments provide multiple ways to add and manage libraries, each optimized for different scenarios such as fast iteration, production stability, or custom package control. This table summarizes the available options and when to use each.
| Option | Typical use case | Environment publish | Starting session | Key benefit |
| Full mode |
| 3-6 minutes (depends on library size and complexity) | 1-3 mins waiting time to deploy the library snapshot (depends on library size and complexity) |
|
| Full mode with custom live pool |
| 3-6 mins (include custom live pool creation) | ~ 5 seconds |
|
| Quick mode |
| ~5 seconds | Extra time to install libraries when notebook session starts (depends on library size and complexity) |
|
| Resources folder |
| Not affected by Environment publishing | Installed manually from the Resources folder |
|
| Inline installation |
| Not affected by Environment publishing | Installed manually using inline commands |
|
Figure: Library management options in Fabric environments and notebooks.
Select the suitable method depending on your situation and stage of development
Choosing the right approach helps you iterate faster during development while keeping production environments stable and reproducible.
In this section, several real-world scenarios show how to combine inline installation, the Resources folder, Quick mode, and Full mode to manage libraries efficiently throughout the lifecycle of a project.
Starting a new project in Fabric
When you’re starting a new project, requirements are often uncertain and dependencies may change frequently.
- Use inline installation to quickly test packages directly in notebooks.
- Use the Resources folder to store custom wheels or JARs that you want to reuse during early exploration.
- Once dependencies become clearer:
- Use Quick mode for lightweight or frequently changing libraries.
- Use Full mode for common or heavier dependencies that you expect to share across notebooks.
This approach lets you validate ideas quickly without paying the cost of environment publishing for every change, and then gradually stabilize the environment as the project takes shape.
Iterating on an existing environment
As your project evolves, you may need to update library versions or introduce new dependencies while keeping the existing environment usable.
- Keep existing libraries in Full mode unchanged to preserve the current snapshot.
- Add new libraries or updated versions to Quick mode.
- Quick mode libraries are installed at notebook session start and override the libraries in Full mode for that session.
This allows you to test changes immediately with fast publishing and startup, while continuing to benefit from the existing snapshot deployed through Full mode. Once the changes are validated, you can decide whether to promote them to Full mode.
Using environments for production workloads
For production scenarios, consistency and reproducibility are critical.
- Move validated libraries from Quick mode to Full mode.
- Publish the environment to generate a stable, validated library snapshot.
- Decide whether to use the custom live pool based on your performance and isolation requirements.
This ensures that all notebooks and jobs run against the same library set, reducing runtime surprises and simplifying operational management.
Key takeaways
You’re now ready to manage libraries effectively in Microsoft Fabric Environments. Use these best practices to stay productive:
- Default to Quick mode for development, Full mode for production.
- Use the Resources folder for custom packages or small resources.
- Treat inline installation as temporary.
- Combining modes is the recommended and supported best practice.
To learn more about managing libraries, refer to Library management in Fabric environments.