StreamSource

Summary

A Tecton StreamSource, used to unify stream and batch data into Tecton for use in a StreamFeatureView.

Example

import pyspark
    from tecton import KinesisConfig, HiveConfig, StreamSource
    from datetime import timedelta


    # Define our deserialization raw stream translator
    def raw_data_deserialization(df:pyspark.sql.DataFrame) -> pyspark.sql.DataFrame:
        from pyspark.sql.functions import col, from_json, from_utc_timestamp
        from pyspark.sql.types import StructType, StringType

        payload_schema = (
          StructType()
                .add('amount', StringType(), False)
                .add('isFraud', StringType(), False)
                .add('timestamp', StringType(), False)
        )
        return (
            df.selectExpr('cast (data as STRING) jsonData')
            .select(from_json('jsonData', payload_schema).alias('payload'))
            .select(
                col('payload.amount').cast('long').alias('amount'),
                col('payload.isFraud').cast('long').alias('isFraud'),
                from_utc_timestamp('payload.timestamp', 'UTC').alias('timestamp')
            )
        )

    # Declare a StreamSource with both a batch_config and a stream_config as parameters
    # See the API documentation for both BatchConfig and StreamConfig
    transactions_stream = StreamSource(
        name='transactions_stream',
        stream_config=KinesisConfig(
            stream_name='transaction_events',
            region='us-west-2',
            initial_stream_position='latest',
            watermark_delay_threshold=timedelta(minutes=30),
            timestamp_field='timestamp',
            post_processor=raw_data_deserialization, # deserialization function defined above
            options={'roleArn': 'arn:aws:iam::472542229217:role/demo-cross-account-kinesis-ro'}
        ),
        batch_config=HiveConfig(
            database='demo_fraud',
            table='transactions',
            timestamp_field='timestamp',
        ),
        owner='user@tecton.ai',
        tags={'release': 'staging'}
    )

Attributes

Name	Data Type	Description
created_at	Optional[datetime.datetime]	Returns the time that this Tecton object was created or last updated. None for locally defined objects.
data_delay	Optional[datetime.timedelta]	Returns the duration that materialization jobs wait after the batch_schedule before starting, typically to ensure that all data has landed.
defined_in	Optional[str]	The repo filename where this object was declared. None for locally defined objects.
description	Optional[str]	Returns the description of the Tecton object.
id	str	Returns the unique id of the Tecton object.
info
name	str	Returns the name of the Tecton object.
owner	Optional[str]	Returns the owner of the Tecton object.
prevent_destroy	bool	Return whether entity has prevent_destroy flagged
tags	Dict[str, str]	Returns the tags of the Tecton object.
workspace	Optional[str]	Returns the workspace that this Tecton object belongs to. None for locally defined objects.

Methods

Name	Description
__init__(...)	Creates a new StreamSource.
get_dataframe(...)	Returns the data in this Data Source as a Tecton DataFrame.
ingest(...)	Ingests a list of events, or a single event, into the Tecton Stream Ingest API.
select_range(...)	Returns this DataSource object wrapped as a FilteredSource. FilteredSources will automatically pre-filter
start_stream_preview(...)	Starts a streaming job to write incoming records from this DS's stream to a temporary table with a given name.
summary()	Displays a human-readable summary.
unfiltered()	Return an unfiltered DataSource. This scope will make an entire source available to a Feature View, but can
validate()	Method is deprecated and will be removed in a future version. As of Tecton version 1.0, objects are validated upon object creation, so validation is unnecessary.

__init__(...)

Creates a new StreamSource.

Parameters

• name (str) - A unique name of the DataSource.


• description (Optional[str]) - A human-readable description. Default: None


• tags (Optional[Dict[str, str]]) - Tags associated with this Tecton Object (key-value pairs of arbitrary metadata). Default: None


• owner (Optional[str]) - Owner name (typically the email of the primary maintainer). Default: None


• prevent_destroy (bool) - If True, this Tecton object will be blocked from being deleted or re-created (i.e. a destructive update) during tecton plan/apply. To remove or update this object, prevent_destroy must be set to False via the same tecton apply or a separate tecton apply. prevent_destroy can be used to prevent accidental changes such as inadvertently deleting a Feature Service used in production or recreating a Feature View that triggers expensive rematerialization jobs. prevent_destroy also blocks changes to dependent Tecton objects that would trigger a recreate of the tagged object, e.g. if prevent_destroy is set on a Feature Service, that will also prevent deletions or re-creates of Feature Views used in that service. prevent_destroy is only enforced in live (i.e. non-dev) workspaces. Default: false


• batch_config (Optional[BatchConfigType]) - BatchConfig object containing the configuration of the Batch Data Source that backs this Tecton Stream Source. This field is optional only if stream_config is a PushConfig. Default: None


• stream_config (StreamConfigType) - StreamConfig object containing the configuration of the Stream Data Source that backs this Tecton Stream Source.


• options (Optional[Dict[str, str]]) - Additional options to configure the Source. Used for advanced use cases and beta features. Default: None


• schema (Optional[List[types.Field]]) - A schema for the StreamSource. If not provided, the schema will be inferred from the underlying batch source. Right now, schemas can only be specified for StreamSources with a PushConfig, and that's also why the schema must be a list of Tecton types. Default: None

get_dataframe(...)

Returns the data in this Data Source as a Tecton DataFrame.

Parameters

• start_time (Optional[datetime.datetime]) - The interval start time from when we want to retrieve source data. If no timezone is specified, will default to using UTC. Can only be defined if apply_translator is True. Default: None


• end_time (Optional[datetime.datetime]) - The interval end time until when we want to retrieve source data. If no timezone is specified, will default to using UTC. Can only be defined if apply_translator is True. Default: None


• apply_translator (bool) - If True, the transformation specified by post_processor will be applied to the dataframe for the data source. apply_translator is not applicable to batch sources configured with spark_batch_config because it does not have a post_processor. Default: true


• compute_mode (Optional[Union[ComputeMode, str]]) - Compute mode to use to produce the data frame. Default: None

Returns

data_frame.TectonDataFrame: A Tecton DataFrame containing the data source's raw or translated source data.

Raises

• TectonValidationError: If apply_translator is False, but start_time or end_time filters are passed in.

ingest(...)

Ingests a list of events, or a single event, into the Tecton Stream Ingest API.

Parameters

• events (Union[Dict[str, Any], Sequence[Dict[str, Any]]]) - A list of dictionaries representing a sequence of events to be ingested. Also accepts a single dictionary.


• dry_run (bool) - If True, the ingest request will be validated, but the event will not be materialized to the online store. If False, the event will be materialized. Default: false

Returns

Dict[str, Any]

start_stream_preview(...)

Starts a streaming job to write incoming records from this DS's stream to a temporary table with a given name.
 
After records have been written to the table, they can be queried using spark.sql(). If ran in a Databricks notebook, Databricks will also automatically visualize the number of incoming records.
 
This is a testing method, most commonly used to verify a StreamDataSource is correctly receiving streaming events. Note that the table will grow infinitely large, so this is only really useful for debugging in notebooks.

Parameters

• table_name (str) - The name of the temporary table that this method will write to.


• apply_translator (bool) - Whether to apply this data source's raw_stream_translator. When True, the translated data will be written to the table. When False, the raw, untranslated data will be written. apply_translator is not applicable to stream sources configured with spark_stream_config because it does not have a post_processor. Default: true


• option_overrides (Optional[Dict[str, str]]) - A dictionary of Spark readStream options that will override any readStream options set by the data source. Can be used to configure behavior only for the preview, e.g. setting startingOffsets:latest to preview only the most recent events in a Kafka stream. Default: None


• checkpoint_dir (Optional[str]) - A root directory where a temporary folder will be created and used by the streaming job for checkpointing. Primarily intended for use with Databricks Unity Catalog Shared Access Mode Clusters. If specified, the environment should have write permission for the specified directory. If not provided, a temporary directory will be created using the default file system. Default: None

Returns

pyspark_streaming.StreamingQuery

summary()

Displays a human-readable summary.

(Deprecated) validate()

Method is deprecated and will be removed in a future version. As of Tecton version 1.0, objects are validated upon object creation, so validation is unnecessary.

Returns

None