Deployment Units

To create a new deployment unit, click Add deployment unit and specify the name for it in the subsequent dialog. The newly created deployment unit is stored as a draft, and is only stored in the frontend.

To add dependencies, click Add artifact. In the subsequent dialog, you can specify where to procure artifacts from:

After you add all dependencies you need, click Deploy version. Nebula will pass the list of dependencies to the cluster, and the deployment unit status will be changed to Downloading. When download is complete, the status will be changed to Available, and you can start your Distributed Computing tasks.

Deployment units are immutable, so you need to create and deploy a new version each time you want to change dependencies. To do this:

After you do this, Nebula will start downloading new dependencies. Old deployment unit version status will be changed to Retiring. It will have this status as long as there are jobs that use this class loader. When there are no jobs, the version will be Decommissioned.

Nebula stores all deployment unit versions and lists them in the Version history table. The table provides the following information:

If you want to switch to an older version (for example, one of the updated dependencies did not work as expected), you can deploy the previous version.

Nebula will create a new version and copy all dependencies from the version you chose.