Worker Versioning (Legacy) - Python SDK

(Deprecated) How to use Worker Versioning in Python

caution

This section is for a previous Worker Versioning API that is deprecated and will go away at some point. Please redirect your attention to Worker Versioning.

See the Pre-release README for more information.

A Build ID corresponds to a deployment. If you don't already have one, we recommend a hash of the code--such as a Git SHA--combined with a human-readable timestamp. To use Worker Versioning, you need to pass a Build ID to your Java Worker and opt in to Worker Versioning.

Assign a Build ID to your Worker and opt in to Worker Versioning

You should understand assignment rules before completing this step. See the Worker Versioning Pre-release README for more information.

To enable Worker Versioning for your Worker, assign the Build ID--perhaps from an environment variable--and turn it on.

# ...
worker = Worker(
  task_queue="your_task_queue_name",
  build_id=build_id,
  use_worker_versioning=True,
  # ... register workflows & activities, etc
)
# ...

danger

Importantly, when you start this Worker, it won't receive any tasks until you set up assignment rules.

Specify versions for Activities, Child Workflows, and Continue-as-New Workflows

caution

Python support for this feature is under construction!

By default, Activities, Child Workflows, and Continue-as-New Workflows are run on the build of the workflow that created them if they are also configured to run on the same Task Queue. When configured to run on a separate Task Queue, they will default to using the current assignment rules.

If you want to override this behavior, you can specify your intent via the versioning_intent argument available on the methods you use to invoke these commands.

For example, if you want an Activity to use the latest assignment rules rather than inheriting from its parent:

# ...
await workflow.execute_activity(
    say_hello,
    "hi",
    versioning_intent=VersioningIntent.USE_ASSIGNMENT_RULES,
    start_to_close_timeout=timedelta(seconds=5),
)
# ...

Tell the Task Queue about your Worker's Build ID (Deprecated)

caution

This section is for a previous Worker Versioning API that is deprecated and will go away at some point. Please redirect your attention to Worker Versioning.

Now you can use the SDK (or the Temporal CLI) to tell the Task Queue about your Worker's Build ID. You might want to do this as part of your CI deployment process.

# ...
await client.update_worker_build_id_compatibility(
    "your_task_queue_name", BuildIdOpAddNewDefault("deadbeef")
)

This code adds the deadbeef Build ID to the Task Queue as the sole version in a new version set, which becomes the default for the queue. New Workflows execute on Workers with this Build ID, and existing ones will continue to process by appropriately compatible Workers.

If, instead, you want to add the Build ID to an existing compatible set, you can do this:

# ...
await client.update_worker_build_id_compatibility(
    "your_task_queue_name", BuildIdOpAddNewCompatible("deadbeef", "some-existing-build-id")
)

This code adds deadbeef to the existing compatible set containing some-existing-build-id and marks it as the new default Build ID for that set.

You can also promote an existing Build ID in a set to be the default for that set:

# ...
await client.update_worker_build_id_compatibility(
    "your_task_queue_name", BuildIdOpPromoteBuildIdWithinSet("deadbeef")
)

You can also promote an entire set to become the default set for the queue. New Workflows will start using that set's default build.

# ...
await client.update_worker_build_id_compatibility(
    "your_task_queue_name", BuildIdOpPromoteSetByBuildId("deadbeef")
)