pipelinewise-target-redshift 1.0.2

Singer.io target for loading data to Amazon Redshift - PipelineWise compatible

pipelinewise-target-redshift

Singer target that loads data into Snowflake following the Singer spec.

This is a PipelineWise compatible target connector.

How to use it

The recommended method of running this target is to use it from PipelineWise. When running it from PipelineWise you don't need to configure this tap with JSON files and most of things are automated. Please check the related documentation at Target Redshift

If you want to run this Singer Target independently please read further.

Install

First, make sure Python 3 is installed on your system or follow these installation instructions for Mac or Ubuntu.

It's recommended to use a virtualenv:

  python3 -m venv venv
  . venv/bin/activate
  pip install --upgrade pip
  pip install pipelinewise-target-redshift

or

  python3 -m venv venv
  . venv/bin/activate
  pip install --upgrade pip
  pip install .

To run

Like any other target that's following the singer specificiation:

some-singer-tap | target-redshift --config [config.json]

It's reading incoming messages from STDIN and using the properites in config.json to upload data into Amazon Redshift.

Note: To avoid version conflicts run tap and targets in separate virtual environments.

Configuration settings

Running the the target connector requires a config.json file. Example with the minimal settings:

{

  "host": "xxxxxx.redshift.amazonaws.com",
  "port": 5439,
  "user": "my_user",
  "password": "password",
  "dbname": "database_name",
  "aws_access_key_id": "secret",
  "aws_secret_access_key": "secret",
  "s3_bucket": "bucket_name",
  "default_target_schema": "my_target_schema"
}

Full list of options in config.json:

Property	Type	Required?	Description
host	String	Yes	Redshift Host
port	Integer	Yes	Redshift Port
user	String	Yes	Redshift User
password	String	Yes	Redshift Password
dbname	String	Yes	Redshift Database name
aws_access_key_id	String	Yes	S3 Access Key Id
aws_secret_access_key	String	Yes	S3 Secret Access Key
s3_bucket	String	Yes	S3 Bucket name
s3_key_prefix	String		(Default: None) A static prefix before the generated S3 key names. Using prefixes you can upload files into specific directories in the S3 bucket.
batch_size	Integer		(Default: 100000) Maximum number of rows in each batch. At the end of each batch, the rows in the batch are loaded into Snowflake.
default_target_schema	String		Name of the schema where the tables will be created. If schema_mapping is not defined then every stream sent by the tap is loaded into this schema.
default_target_schema_select_permission	String		Grant USAGE privilege on newly created schemas and grant SELECT privilege on newly created tables to a specific role or a list of roles. If schema_mapping is not defined then every stream sent by the tap is granted accordingly.
schema_mapping	Object		Useful if you want to load multiple streams from one tap to multiple Snowflake schemas. If the tap sends the stream_id in <schema_name>-<table_name> format then this option overwrites the default_target_schema value. Note, that using schema_mapping you can overwrite the default_target_schema_select_permission value to grant SELECT permissions to different groups per schemas or optionally you can create indices automatically for the replicated tables. Note: This is an experimental feature and recommended to use via PipelineWise YAML files that will generate the object mapping in the right JSON format. For further info check a [PipelineWise YAML Example]
disable_table_cache	Boolean		(Default: False) By default the connector caches the available table structures in Redshift at startup. In this way it doesn't need to run additional queries when ingesting data to check if altering the target tables is required. With disable_table_cache option you can turn off this caching. You will always see the most recent table structures but will cause an extra query runtime.
add_metadata_columns	Boolean		(Default: False) Metadata columns add extra row level information about data ingestions, (i.e. when was the row read in source, when was inserted or deleted in redshift etc.) Metadata columns are creating automatically by adding extra columns to the tables with a column prefix _SDC_. The metadata columns are documented at https://transferwise.github.io/pipelinewise/data_structure/sdc-columns.html. Enabling metadata columns will flag the deleted rows by setting the _SDC_DELETED_AT metadata column. Without the add_metadata_columns option the deleted rows from singer taps will not be recongisable in Snowflake.
hard_delete	Boolean		(Default: False) When hard_delete option is true then DELETE SQL commands will be performed in Snowflake to delete rows in tables. It's achieved by continuously checking the _SDC_DELETED_AT metadata column sent by the singer tap. Due to deleting rows requires metadata columns, hard_delete option automatically enables the add_metadata_columns option as well.
data_flattening_max_level	Integer		(Default: 0) Object type RECORD items from taps can be loaded into VARIANT columns as JSON (default) or we can flatten the schema by creating columns automatically. When value is 0 (default) then flattening functionality is turned off.

To run tests:

1. Install python dependencies in a virtual env:

  python3 -m venv venv
  . venv/bin/activate
  pip install --upgrade pip
  pip install .
  pip install pytest coverage

3. To run unit tests:

  coverage run -m pytest --disable-pytest-warnings tests/unit && coverage report

1. To run integration tests define environment variables first:

  export TARGET_REDSHIFT_HOST=<redshift-host>
  export TARGET_REDSHIFT_PORT=<redshift-port>
  export TARGET_REDSHIFT_USER=<redshift-user>
  export TARGET_REDSHIFT_PASSWORD=<redshift-password>
  export TARGET_REDSHIFT_DBNAME=<redshift-database-name>
  export TARGET_REDSHIFT_SCHEMA=<redshift-target-schema>
  export TARGET_REDSHIFT_AWS_ACCESS_KEY=<aws-access-key-id>
  export TARGET_REDSHIFT_AWS_SECRET_ACCESS_KEY=<aws-access-secret-access-key>
  export TARGET_REDSHIFT_S3_BUCKET=<s3-bucket>
  export TARGET_REDSHIFT_S3_KEY_PREFIX=<s3-bucket-directory>

  coverage run -m pytest --disable-pytest-warnings tests/integration && coverage report

To run pylint:

1. Install python dependencies and run python linter

  python3 -m venv venv
  . venv/bin/activate
  pip install --upgrade pip
  pip install .
  pip install pylint
  pylint target_redshift -d C,W,unexpected-keyword-arg,duplicate-code