How do I configure that backfill jobs for an asset with a limit on concurrency based on a tag using the

define_asset_job

method?

To configure backfill jobs for an asset with a limit on concurrency based on a tag using the

define_asset_job

method, you can follow these steps: 1. Define your asset job with the

define_asset_job

method and include the desired tags within the job definition. These tags will be used to apply concurrency limits. 2. Configure the

run_coordinator

in your

dagster.yaml

file to include

tag_concurrency_limits

. This configuration will specify the concurrency limits based on the tags you set in your job definition. Here's an example of how you might define an asset job with a tag and set up the concurrency limits in the `dagster.yaml`:

python # Define your asset job with a tag test_controlled_backfill = define_asset_job(     name="test_controlled_backfill",     selection=AssetSelection.groups("your_asset_group"),     tags={         "serial_backfill": "test_controlled_backfill"     } )

And in your `dagster.yaml`:

yaml run_coordinator:   module: dagster.core.run_coordinator   class: QueuedRunCoordinator    config:     tag_concurrency_limits:       - key: "serial_backfill"         limit: 1         value:           applyLimitPerUniqueValue: true

In this configuration, the

tag_concurrency_limits

is set to allow only 1 concurrent run per unique value of the

serial_backfill

tag. This means that backfills for the job

test_controlled_backfill

will be limited to one run at a time. Please note that the exact configuration might vary depending on your specific use case and the version of Dagster you are using. Always refer to the latest Dagster documentation for the most accurate and up-to-date information.

@Scout instead of

dagster.yaml

, can I also define the

tag_concurrency_limits

in the `define_asset_job`'s

config

attribute?

No, according to the documentation,

tag_concurrency_limits

should be specified in the

dagster.yaml

file under the

run_coordinator

configuration, not directly within the `define_asset_job`'s

config

attribute. The

tag_concurrency_limits

configuration is part of the instance-wide settings that determine how runs are queued and executed. These settings are not part of the job's definition but rather part of the Dagster instance's operational configuration. To apply concurrency limits based on tags, you should update your

dagster.yaml

file as shown in the previous example. This will ensure that the concurrency limits are respected by the Dagster instance when queuing and running jobs.

@Scout according to the documentation in https://docs.dagster.io/guides/limiting-concurrency-in-data-pipelines#limiting-concurrency-using-tags, this is possible, but when configuring my job, I get an error

Backfill failed for simple: dagster._core.errors.DagsterInvalidConfigError: Error in config for job meta_assets_job
    Error 1: Received unexpected config entry "multiprocess" at path root:execution:config

The error message you're encountering indicates that there's an unexpected configuration entry

multiprocess

in the job configuration. This suggests that there might be a mismatch between the configuration you're providing and what Dagster expects. Based on the documentation, the

tag_concurrency_limits

should be set in the

dagster.yaml

for the Dagster instance, not within the job's

config

attribute. The

multiprocess

configuration entry is typically used to configure an executor within a job, but it seems like it's being placed incorrectly or is not expected in the context where you've added it. Here's what you should do: 1. Ensure that the

tag_concurrency_limits

are specified in the

dagster.yaml

file under the

run_coordinator

configuration, not within the job's

config

. 2. If you're trying to configure the executor for the job to use multiple processes, make sure you're using the correct configuration structure. For example, if you're using the

multiprocess_executor

, it should be configured as follows:

python from dagster import job, multiprocess_executor  @job(executor_def=multiprocess_executor.configured({"max_concurrent": 4})) def my_job():     ...

3. If you're trying to set

tag_concurrency_limits

for the job, this should be done in the

dagster.yaml

as part of the

run_coordinator

configuration:

yaml run_coordinator:   module: dagster.core.run_coordinator   class: QueuedRunCoordinator   config:     tag_concurrency_limits:       - key: "my_tag"         limit: 1

4. If you continue to encounter issues, double-check the documentation for the version of Dagster you're using, as configuration options can change between versions. If you've followed the documentation and are still encountering issues, it might be helpful to provide more context or the specific configuration you're using so that we can troubleshoot further.