airflow.providers.google.cloud.transfers.cassandra_to_gcs¶
This module contains operator for copying data from Cassandra to Google Cloud Storage in JSON format.
Module Contents¶
Classes¶
Copy data from Cassandra to Google Cloud Storage in JSON format |
Attributes¶
- class airflow.providers.google.cloud.transfers.cassandra_to_gcs.CassandraToGCSOperator(*, cql, bucket, filename, schema_filename=None, approx_max_file_size_bytes=1900000000, gzip=False, cassandra_conn_id='cassandra_default', gcp_conn_id='google_cloud_default', delegate_to=None, impersonation_chain=None, query_timeout=NOT_SET, **kwargs)[source]¶
Bases:
airflow.models.BaseOperatorCopy data from Cassandra to Google Cloud Storage in JSON format
Note: Arrays of arrays are not supported.
- Parameters
cql (str) -- The CQL to execute on the Cassandra table.
bucket (str) -- The bucket to upload to.
filename (str) -- The filename to use as the object name when uploading to Google Cloud Storage. A {} should be specified in the filename to allow the operator to inject file numbers in cases where the file is split due to size.
schema_filename (Optional[str]) -- If set, the filename to use as the object name when uploading a .json file containing the BigQuery schema fields for the table that was dumped from MySQL.
approx_max_file_size_bytes (int) -- This operator supports the ability to split large table dumps into multiple files (see notes in the filename param docs above). This param allows developers to specify the file size of the splits. Check https://cloud.google.com/storage/quotas to see the maximum allowed file size for a single object.
cassandra_conn_id (str) -- Reference to a specific Cassandra hook.
gzip (bool) -- Option to compress file for upload
gcp_conn_id (str) -- (Optional) The connection ID used to connect to Google Cloud.
delegate_to (Optional[str]) -- The account to impersonate using domain-wide delegation of authority, if any. For this to work, the service account making the request must have domain-wide delegation enabled.
impersonation_chain (Optional[Union[str, Sequence[str]]]) -- Optional service account to impersonate using short-term credentials, or chained list of accounts required to get the access_token of the last account in the list, which will be impersonated in the request. If set as a string, the account must grant the originating account the Service Account Token Creator IAM role. If set as a sequence, the identities from the list must grant Service Account Token Creator IAM role to the directly preceding identity, with first account from the list granting this role to the originating account (templated).
query_timeout (Union[float, None, NotSetType]) -- (Optional) The amount of time, in seconds, used to execute the Cassandra query. If not set, the timeout value will be set in Session.execute() by Cassandra driver. If set to None, there is no timeout.
- template_fields :Sequence[str] = ['cql', 'bucket', 'filename', 'schema_filename', 'impersonation_chain'][source]¶
- execute(self, context)[source]¶
This is the main method to derive when creating an operator. Context is the same dictionary used as when rendering jinja templates.
Refer to get_template_context for more context.
- classmethod generate_data_dict(cls, names, values)[source]¶
Generates data structure that will be stored as file in GCS.
- classmethod convert_user_type(cls, value)[source]¶
Converts a user type to RECORD that contains n fields, where n is the number of attributes. Each element in the user type class will be converted to its corresponding data type in BQ.
- classmethod convert_tuple_type(cls, values)[source]¶
Converts a tuple to RECORD that contains n fields, each will be converted to its corresponding data type in bq and will be named 'field_<index>', where index is determined by the order of the tuple elements defined in cassandra.