Source code for airflow.hooks.druid_hook

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from __future__ import print_function

import requests
import time

from pydruid.db import connect

from airflow.exceptions import AirflowException
from airflow.hooks.base_hook import BaseHook
from airflow.hooks.dbapi_hook import DbApiHook


[docs]class DruidHook(BaseHook): """ Connection to Druid overlord for ingestion :param druid_ingest_conn_id: The connection id to the Druid overlord machine which accepts index jobs :type druid_ingest_conn_id: string :param timeout: The interval between polling the Druid job for the status of the ingestion job. Must be greater than or equal to 1 :type timeout: int :param max_ingestion_time: The maximum ingestion time before assuming the job failed :type max_ingestion_time: int """ def __init__( self, druid_ingest_conn_id='druid_ingest_default', timeout=1, max_ingestion_time=None): self.druid_ingest_conn_id = druid_ingest_conn_id self.timeout = timeout self.max_ingestion_time = max_ingestion_time self.header = {'content-type': 'application/json'} if self.timeout < 1: raise ValueError("Druid timeout should be equal or greater than 1") def get_conn_url(self): conn = self.get_connection(self.druid_ingest_conn_id) host = conn.host port = conn.port conn_type = 'http' if not conn.conn_type else conn.conn_type endpoint = conn.extra_dejson.get('endpoint', '') return "{conn_type}://{host}:{port}/{endpoint}".format(**locals()) def submit_indexing_job(self, json_index_spec): url = self.get_conn_url() self.log.info("Druid ingestion spec: {}".format(json_index_spec)) req_index = requests.post(url, json=json_index_spec, headers=self.header) if (req_index.status_code != 200): raise AirflowException('Did not get 200 when ' 'submitting the Druid job to {}'.format(url)) req_json = req_index.json() # Wait until the job is completed druid_task_id = req_json['task'] self.log.info("Druid indexing task-id: {}".format(druid_task_id)) running = True sec = 0 while running: req_status = requests.get("{0}/{1}/status".format(url, druid_task_id)) self.log.info("Job still running for %s seconds...", sec) if self.max_ingestion_time and sec > self.max_ingestion_time: # ensure that the job gets killed if the max ingestion time is exceeded requests.post("{0}/{1}/shutdown".format(url, druid_task_id)) raise AirflowException('Druid ingestion took more than ' '%s seconds', self.max_ingestion_time) time.sleep(self.timeout) sec = sec + self.timeout status = req_status.json()['status']['status'] if status == 'RUNNING': running = True elif status == 'SUCCESS': running = False # Great success! elif status == 'FAILED': raise AirflowException('Druid indexing job failed, ' 'check console for more info') else: raise AirflowException('Could not get status of the job, got %s', status) self.log.info('Successful index')
[docs]class DruidDbApiHook(DbApiHook): """ Interact with Druid broker This hook is purely for users to query druid broker. For ingestion, please use druidHook. """ conn_name_attr = 'druid_broker_conn_id' default_conn_name = 'druid_broker_default' supports_autocommit = False def __init__(self, *args, **kwargs): super(DruidDbApiHook, self).__init__(*args, **kwargs)
[docs] def get_conn(self): """ Establish a connection to druid broker. """ conn = self.get_connection(self.druid_broker_conn_id) druid_broker_conn = connect( host=conn.host, port=conn.port, path=conn.extra_dejson.get('endpoint', '/druid/v2/sql'), scheme=conn.extra_dejson.get('schema', 'http') ) self.log.info('Get the connection to druid ' 'broker on {host}'.format(host=conn.host)) return druid_broker_conn
[docs] def get_uri(self): """ Get the connection uri for druid broker. e.g: druid://localhost:8082/druid/v2/sql/ """ conn = self.get_connection(getattr(self, self.conn_name_attr)) host = conn.host if conn.port is not None: host += ':{port}'.format(port=conn.port) conn_type = 'druid' if not conn.conn_type else conn.conn_type endpoint = conn.extra_dejson.get('endpoint', 'druid/v2/sql') return '{conn_type}://{host}/{endpoint}'.format( conn_type=conn_type, host=host, endpoint=endpoint)
[docs] def set_autocommit(self, conn, autocommit): raise NotImplementedError()
[docs] def get_pandas_df(self, sql, parameters=None): raise NotImplementedError()
[docs] def insert_rows(self, table, rows, target_fields=None, commit_every=1000): raise NotImplementedError()