Sandeep Mullangi
03/13/2024, 4:57 PMScout
03/13/2024, 4:57 PMRunRequest
object in Dagster is designed to request a run for a specific partition when working with partitioned assets or jobs. As per the documentation, the partition_key
parameter of a RunRequest
is a string that specifies the key of the partition for which you want to request a run. If you need to handle multiple partitions within a single run, you would typically iterate over the partition keys and create a separate RunRequest
for each one. However, this approach may not be suitable if you want to process multiple partitions within a single run to reduce overhead. The documentation does not explicitly provide a built-in method for submitting a single RunRequest
for multiple partition keys. However, there are discussions and issues that suggest workarounds or feature requests related to handling multiple partitions. One such discussion suggests that you can use tags to include information about a range of partitions when creating a RunRequest
. For example, you could use reserved tags like ASSET_PARTITION_RANGE_START_TAG
and ASSET_PARTITION_RANGE_END_TAG
to specify a range of partitions to process in a single run. Here's an example from the discussions: python @sensor(asset_selection=AssetSelection.keys(my_asset.key)) def stations_sensor(context): stations = ["1", "2", "3"] return SensorResult( run_requests=[RunRequest(run_key=None, tags={"dagster/partition_start": "1", "dagster/partition_end": "3"})], dynamic_partitions_requests=[stations_partition.build_add_request(stations)], )
In this example, the tags are used to indicate a range of partitions to be processed. However, this is not a standard feature and would require custom handling in your job logic to interpret these tags and process the appropriate partitions. If you have a specific use case that requires processing multiple partitions in a single run and the current RunRequest
functionality does not meet your needs, you may consider reaching out on the Dagster GitHub discussions or issues to inquire about potential features or best practices for such scenarios.Sandeep Mullangi
03/13/2024, 5:31 PMScout
03/13/2024, 5:31 PMRunRequest
in a job and pass them to an op, you can use the run_config
field of the RunRequest
to specify the configuration for the job. This configuration can include parameters that your ops need to execute. Here's a step-by-step guide on how to do this: 1. Define your op with the required configuration schema. The op should accept a context parameter from which you can access the configuration values. 2. Create a job that includes this op. 3. Define a schedule that returns a RunRequest
with the run_config
field set. The run_config
should match the structure expected by the job and its ops. 4. When the schedule triggers a run, Dagster will use the run_config
provided in the RunRequest
to configure the job and its ops. Here's an example to illustrate this process: python from dagster import job, op, schedule, RunRequest # Define an op that requires configuration @op(config_schema={"param": str}) def my_op(context): # Access the configuration parameter param = context.op_config["param"] <http://context.log.info|context.log.info>(f"Parameter value: {param}") # Create a job that includes the op @job def my_job(): my_op() # Define a schedule that returns a RunRequest with parameters @schedule(cron_schedule="0 0 * * *", job=my_job) def my_schedule(context): # Define the run configuration with the parameter you want to pass run_config = { "ops": { "my_op": { "config": { "param": "value_from_schedule" } } } } # Return a RunRequest with the run configuration return RunRequest(run_key=context.scheduled_execution_time.strftime("%Y-%m-%d"), run_config=run_config) # When the schedule triggers a run, it will use the run_config provided in the RunRequest # to configure the job and pass the parameter to the op.
In this example, the my_schedule
schedule creates a RunRequest
with a run_config
that specifies the configuration for my_op
. When the schedule triggers a run, the param
value will be passed to my_op
, and the op will log the parameter value. Make sure that the structure of the run_config
in the RunRequest
matches the expected configuration schema of your job and ops. This way, the parameters will be correctly passed through when the job is executed.Sandeep Mullangi
03/14/2024, 12:18 PMScout
03/14/2024, 12:18 PM@op
decorator is almost correct, but there are a few adjustments needed to align with the correct usage according to the documentation. Here's the corrected syntax based on the documentation: python from dagster import op, Out # Define an op with required resources, a config schema, and an output definition @op(required_resource_keys={"dbt"}, config_schema={"param": list, "model_name": str}) def my_op(context): # Access resources and config dbt = context.resources.dbt param = context.op_config["param"] model_name = context.op_config["model_name"] # Your logic here... # Return a result return "result"
In this corrected syntax: - The config_schema
is defined correctly with the types for each config field. - The required_resource_keys
is a set of strings that specify the resource handles required by this op. - The out
parameter is not needed in this case because by default, an op has a single output named result
. If you want to specify the output definition explicitly, you can use the Out
class, but it's not necessary unless you need to customize the output behavior. If you do want to customize the output, you would include the Out
class within the body of the op definition, like this: python from dagster import op, Out @op(required_resource_keys={"dbt"}, config_schema={"param": list, "model_name": str}) def my_op(context): # Access resources and config dbt = context.resources.dbt param = context.op_config["param"] model_name = context.op_config["model_name"] # Your logic here... # Return a result using the Output class yield Out("result")
However, if you're using the return
statement, you don't need to define out
explicitly unless you have multiple outputs or need to customize the output. If you do have multiple outputs, you would define them in a dictionary passed to the out
parameter, and use yield
to emit each output: python from dagster import op, Out @op(required_resource_keys={"dbt"}, config_schema={"param": list, "model_name": str}, out={"result": Out(), "another_result": Out()}) def my_op(context): # Access resources and config dbt = context.resources.dbt param = context.op_config["param"] model_name = context.op_config["model_name"] # Your logic here... # Yield multiple results yield Out("result", value="first_result") yield Out("another_result", value="second_result")
Remember to adjust your op's logic to match the configuration and resource requirements you've specified.