OSGi bundle lifecycle

[EthanRo5]

Hi all,

Is there any detailed source where I can understand the different states of the OSGi bundle lifecycle more clearly?

[SantoshSai · Accepted solution]

Hi @EthanRo5,

I think, a great place to start is the official OSGi specification, which explains the bundle lifecycle in depth.I have also provided a detailed explanation with a practical demo in the blog post “OSGi Bundle Lifecycle”.. where you will understand below points: 

1. Lifecycle
2. Bundle Lifecycle : Resolved
3. Lifecycle : Starting
4. Lifecycle : Active and Beyond
5. Bundle Class Loading
6. Bundle Fragments
7. Summary

For a more practical approach, the Apache Felix documentation also offers insights into how bundles behave within an OSGi container like AEM.

Hope that helps!

[partyush]

@SantoshSai  even I learned this thing from your blogs and videos 🙂  

Thanks for the amazing content.

[ShivamKumar]

Hi @EthanRo5 ,

Understanding the OSGi bundle lifecycle is crucial to knowing how OSGi components operate. The main stages are:

1. Installed:
   The bundle is deployed into the OSGi container, but its dependencies haven't been resolved yet.
2. Resolved:
   All the bundle's dependencies are met, and it's ready to be started.
3. Starting:
   The bundle is in the process of being activated, executing its activator code if specified.
4. Active:
   The bundle is fully initialized, running, and ready to be used, with services registered.
5. Stopping:
   The bundle is being stopped, cleaning up resources, and transitioning back to the Resolved state.
6. Uninstalled:
   The bundle has been removed from the OSGi container and is no longer active.

You can refer to the explanations provided in the links below:

OSGI Bundle LifeCycle-1 

OSGI Bundle LIfeCycle-2 

[pranayr]

Hi @EthanRo5 

I find this article very useful for anyone who needs to understand OSGi bundle lifecycle more clearly : 

https://medium.com/aem-architect-developer-business-practitioner/osgi-bundle-lifecycle-deploying-osg...

And also summing up the stages here too :

1. Installed: When you deploy a bundle, it’s in the “Installed” stage. It’s available to the system, but not running yet.
2. Resolved: After OSGi checks that all bundle requirements are met, the bundle becomes “Resolved.” Dependencies are resolved, but it’s still not active.
3. Starting: The bundle enters the “Starting” stage when it’s being activated. It executes an activator code if specified.
4. Active: Once the bundle is fully initialized and running, it reaches the “Active” stage. Services are registered, and it functions properly.
5. Stopping: If you stop the bundle or there are changes in dependencies, it enters the “Stopping” stage to clean up resources.
6. Uninstalled: Finally, the bundle is “Uninstalled” when it’s removed from the system.

Hope this helps!