airflow hive 源码
airflow hive 代码
文件路径：/airflow/providers/apache/hive/hooks/hive.py
#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
from __future__ import annotations
import contextlib
import os
import re
import socket
import subprocess
import time
import warnings
from collections import OrderedDict
from tempfile import NamedTemporaryFile, TemporaryDirectory
from typing import Any, Iterable, Mapping
import pandas
import unicodecsv as csv
from airflow.configuration import conf
from airflow.exceptions import AirflowException
from airflow.hooks.base import BaseHook
from airflow.providers.common.sql.hooks.sql import DbApiHook
from airflow.security import utils
from airflow.utils.helpers import as_flattened_list
from airflow.utils.operator_helpers import AIRFLOW_VAR_NAME_FORMAT_MAPPING
HIVE_QUEUE_PRIORITIES = ['VERY_HIGH', 'HIGH', 'NORMAL', 'LOW', 'VERY_LOW']
def get_context_from_env_var() -> dict[Any, Any]:
"""
Extract context from env variable, e.g. dag_id, task_id and execution_date,
so that they can be used inside BashOperator and PythonOperator.
:return: The context of interest.
"""
return {
format_map['default']: os.environ.get(format_map['env_var_format'], '')
for format_map in AIRFLOW_VAR_NAME_FORMAT_MAPPING.values()
}
class HiveCliHook(BaseHook):
"""Simple wrapper around the hive CLI.
It also supports the ``beeline``
a lighter CLI that runs JDBC and is replacing the heavier
traditional CLI. To enable ``beeline``, set the use_beeline param in the
extra field of your connection as in ``{ "use_beeline": true }``
Note that you can also set default hive CLI parameters using the
``hive_cli_params`` to be used in your connection as in
``{"hive_cli_params": "-hiveconf mapred.job.tracker=some.jobtracker:444"}``
Parameters passed here can be overridden by run_cli's hive_conf param
The extra connection parameter ``auth`` gets passed as in the ``jdbc``
connection string as is.
:param hive_cli_conn_id: Reference to the
:ref:`Hive CLI connection id <howto/connection:hive_cli>`.
:param mapred_queue: queue used by the Hadoop Scheduler (Capacity or Fair)
:param mapred_queue_priority: priority within the job queue.
Possible settings include: VERY_HIGH, HIGH, NORMAL, LOW, VERY_LOW
:param mapred_job_name: This name will appear in the jobtracker.
This can make monitoring easier.
"""
conn_name_attr = 'hive_cli_conn_id'
default_conn_name = 'hive_cli_default'
conn_type = 'hive_cli'
hook_name = 'Hive Client Wrapper'
def __init__(
self,
hive_cli_conn_id: str = default_conn_name,
run_as: str | None = None,
mapred_queue: str | None = None,
mapred_queue_priority: str | None = None,
mapred_job_name: str | None = None,
) -> None:
super().__init__()
conn = self.get_connection(hive_cli_conn_id)
self.hive_cli_params: str = conn.extra_dejson.get('hive_cli_params', '')
self.use_beeline: bool = conn.extra_dejson.get('use_beeline', False)
self.auth = conn.extra_dejson.get('auth', 'noSasl')
self.conn = conn
self.run_as = run_as
self.sub_process: Any = None
if mapred_queue_priority:
mapred_queue_priority = mapred_queue_priority.upper()
if mapred_queue_priority not in HIVE_QUEUE_PRIORITIES:
raise AirflowException(
f"Invalid Mapred Queue Priority. Valid values are: {', '.join(HIVE_QUEUE_PRIORITIES)}"
)
self.mapred_queue = mapred_queue or conf.get('hive', 'default_hive_mapred_queue')
self.mapred_queue_priority = mapred_queue_priority
self.mapred_job_name = mapred_job_name
def _get_proxy_user(self) -> str:
"""This function set the proper proxy_user value in case the user overwrite the default."""
conn = self.conn
proxy_user_value: str = conn.extra_dejson.get('proxy_user', "")
if proxy_user_value == "login" and conn.login:
return f"hive.server2.proxy.user={conn.login}"
if proxy_user_value == "owner" and self.run_as:
return f"hive.server2.proxy.user={self.run_as}"
if proxy_user_value != "": # There is a custom proxy user
return f"hive.server2.proxy.user={proxy_user_value}"
return proxy_user_value # The default proxy user (undefined)
def _prepare_cli_cmd(self) -> list[Any]:
"""This function creates the command list from available information"""
conn = self.conn
hive_bin = 'hive'
cmd_extra = []
if self.use_beeline:
hive_bin = 'beeline'
jdbc_url = f"jdbc:hive2://{conn.host}:{conn.port}/{conn.schema}"
if conf.get('core', 'security') == 'kerberos':
template = conn.extra_dejson.get('principal', "hive/_HOST@EXAMPLE.COM")
if "_HOST" in template:
template = utils.replace_hostname_pattern(utils.get_components(template))
proxy_user = self._get_proxy_user()
jdbc_url += f";principal={template};{proxy_user}"
elif self.auth:
jdbc_url += ";auth=" + self.auth
jdbc_url = f'"{jdbc_url}"'
cmd_extra += ['-u', jdbc_url]
if conn.login:
cmd_extra += ['-n', conn.login]
if conn.password:
cmd_extra += ['-p', conn.password]
hive_params_list = self.hive_cli_params.split()
return [hive_bin] + cmd_extra + hive_params_list
@staticmethod
def _prepare_hiveconf(d: dict[Any, Any]) -> list[Any]:
"""
This function prepares a list of hiveconf params
from a dictionary of key value pairs.
:param d:
>>> hh = HiveCliHook()
>>> hive_conf = {"hive.exec.dynamic.partition": "true",
... "hive.exec.dynamic.partition.mode": "nonstrict"}
>>> hh._prepare_hiveconf(hive_conf)
["-hiveconf", "hive.exec.dynamic.partition=true",\
"-hiveconf", "hive.exec.dynamic.partition.mode=nonstrict"]
"""
if not d:
return []
return as_flattened_list(zip(["-hiveconf"] * len(d), [f"{k}={v}" for k, v in d.items()]))
def run_cli(
self,
hql: str,
schema: str | None = None,
verbose: bool = True,
hive_conf: dict[Any, Any] | None = None,
) -> Any:
"""
Run an hql statement using the hive cli. If hive_conf is specified
it should be a dict and the entries will be set as key/value pairs
in HiveConf.
:param hql: an hql (hive query language) statement to run with hive cli
:param schema: Name of hive schema (database) to use
:param verbose: Provides additional logging. Defaults to True.
:param hive_conf: if specified these key value pairs will be passed
to hive as ``-hiveconf "key"="value"``. Note that they will be
passed after the ``hive_cli_params`` and thus will override
whatever values are specified in the database.
>>> hh = HiveCliHook()
>>> result = hh.run_cli("USE airflow;")
>>> ("OK" in result)
True
"""
conn = self.conn
schema = schema or conn.schema
if schema:
hql = f"USE {schema};\n{hql}"
with TemporaryDirectory(prefix='airflow_hiveop_') as tmp_dir:
with NamedTemporaryFile(dir=tmp_dir) as f:
hql += '\n'
f.write(hql.encode('UTF-8'))
f.flush()
hive_cmd = self._prepare_cli_cmd()
env_context = get_context_from_env_var()
# Only extend the hive_conf if it is defined.
if hive_conf:
env_context.update(hive_conf)
hive_conf_params = self._prepare_hiveconf(env_context)
if self.mapred_queue:
hive_conf_params.extend(
[
'-hiveconf',
f'mapreduce.job.queuename={self.mapred_queue}',
'-hiveconf',
f'mapred.job.queue.name={self.mapred_queue}',
'-hiveconf',
f'tez.queue.name={self.mapred_queue}',
]
)
if self.mapred_queue_priority:
hive_conf_params.extend(
['-hiveconf', f'mapreduce.job.priority={self.mapred_queue_priority}']
)
if self.mapred_job_name:
hive_conf_params.extend(['-hiveconf', f'mapred.job.name={self.mapred_job_name}'])
hive_cmd.extend(hive_conf_params)
hive_cmd.extend(['-f', f.name])
if verbose:
self.log.info("%s", " ".join(hive_cmd))
sub_process: Any = subprocess.Popen(
hive_cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, cwd=tmp_dir, close_fds=True
)
self.sub_process = sub_process
stdout = ''
while True:
line = sub_process.stdout.readline()
if not line:
break
stdout += line.decode('UTF-8')
if verbose:
self.log.info(line.decode('UTF-8').strip())
sub_process.wait()
if sub_process.returncode:
raise AirflowException(stdout)
return stdout
def test_hql(self, hql: str) -> None:
"""Test an hql statement using the hive cli and EXPLAIN"""
create, insert, other = [], [], []
for query in hql.split(';'): # naive
query_original = query
query = query.lower().strip()
if query.startswith('create table'):
create.append(query_original)
elif query.startswith(('set ', 'add jar ', 'create temporary function')):
other.append(query_original)
elif query.startswith('insert'):
insert.append(query_original)
other_ = ';'.join(other)
for query_set in [create, insert]:
for query in query_set:
query_preview = ' '.join(query.split())[:50]
self.log.info("Testing HQL [%s (...)]", query_preview)
if query_set == insert:
query = other_ + '; explain ' + query
else:
query = 'explain ' + query
try:
self.run_cli(query, verbose=False)
except AirflowException as e:
message = e.args[0].split('\n')[-2]
self.log.info(message)
error_loc = re.search(r'(\d+):(\d+)', message)
if error_loc and error_loc.group(1).isdigit():
lst = int(error_loc.group(1))
begin = max(lst - 2, 0)
end = min(lst + 3, len(query.split('\n')))
context = '\n'.join(query.split('\n')[begin:end])
self.log.info("Context :\n %s", context)
else:
self.log.info("SUCCESS")
def load_df(
self,
df: pandas.DataFrame,
table: str,
field_dict: dict[Any, Any] | None = None,
delimiter: str = ',',
encoding: str = 'utf8',
pandas_kwargs: Any = None,
**kwargs: Any,
) -> None:
"""
Loads a pandas DataFrame into hive.
Hive data types will be inferred if not passed but column names will
not be sanitized.
:param df: DataFrame to load into a Hive table
:param table: target Hive table, use dot notation to target a
specific database
:param field_dict: mapping from column name to hive data type.
Note that it must be OrderedDict so as to keep columns' order.
:param delimiter: field delimiter in the file
:param encoding: str encoding to use when writing DataFrame to file
:param pandas_kwargs: passed to DataFrame.to_csv
:param kwargs: passed to self.load_file
"""
def _infer_field_types_from_df(df: pandas.DataFrame) -> dict[Any, Any]:
dtype_kind_hive_type = {
'b': 'BOOLEAN', # boolean
'i': 'BIGINT', # signed integer
'u': 'BIGINT', # unsigned integer
'f': 'DOUBLE', # floating-point
'c': 'STRING', # complex floating-point
'M': 'TIMESTAMP', # datetime
'O': 'STRING', # object
'S': 'STRING', # (byte-)string
'U': 'STRING', # Unicode
'V': 'STRING', # void
}
order_type = OrderedDict()
for col, dtype in df.dtypes.iteritems():
order_type[col] = dtype_kind_hive_type[dtype.kind]
return order_type
if pandas_kwargs is None:
pandas_kwargs = {}
with TemporaryDirectory(prefix='airflow_hiveop_') as tmp_dir:
with NamedTemporaryFile(dir=tmp_dir, mode="w") as f:
if field_dict is None:
field_dict = _infer_field_types_from_df(df)
df.to_csv(
path_or_buf=f,
sep=delimiter,
header=False,
index=False,
encoding=encoding,
date_format="%Y-%m-%d %H:%M:%S",
**pandas_kwargs,
)
f.flush()
return self.load_file(
filepath=f.name, table=table, delimiter=delimiter, field_dict=field_dict, **kwargs
)
def load_file(
self,
filepath: str,
table: str,
delimiter: str = ",",
field_dict: dict[Any, Any] | None = None,
create: bool = True,
overwrite: bool = True,
partition: dict[str, Any] | None = None,
recreate: bool = False,
tblproperties: dict[str, Any] | None = None,
) -> None:
"""
Loads a local file into Hive
Note that the table generated in Hive uses ``STORED AS textfile``
which isn't the most efficient serialization format. If a
large amount of data is loaded and/or if the tables gets
queried considerably, you may want to use this operator only to
stage the data into a temporary table before loading it into its
final destination using a ``HiveOperator``.
:param filepath: local filepath of the file to load
:param table: target Hive table, use dot notation to target a
specific database
:param delimiter: field delimiter in the file
:param field_dict: A dictionary of the fields name in the file
as keys and their Hive types as values.
Note that it must be OrderedDict so as to keep columns' order.
:param create: whether to create the table if it doesn't exist
:param overwrite: whether to overwrite the data in table or partition
:param partition: target partition as a dict of partition columns
and values
:param recreate: whether to drop and recreate the table at every
execution
:param tblproperties: TBLPROPERTIES of the hive table being created
"""
hql = ''
if recreate:
hql += f"DROP TABLE IF EXISTS {table};\n"
if create or recreate:
if field_dict is None:
raise ValueError("Must provide a field dict when creating a table")
fields = ",\n ".join(f"`{k.strip('`')}` {v}" for k, v in field_dict.items())
hql += f"CREATE TABLE IF NOT EXISTS {table} (\n{fields})\n"
if partition:
pfields = ",\n ".join(p + " STRING" for p in partition)
hql += f"PARTITIONED BY ({pfields})\n"
hql += "ROW FORMAT DELIMITED\n"
hql += f"FIELDS TERMINATED BY '{delimiter}'\n"
hql += "STORED AS textfile\n"
if tblproperties is not None:
tprops = ", ".join(f"'{k}'='{v}'" for k, v in tblproperties.items())
hql += f"TBLPROPERTIES({tprops})\n"
hql += ";"
self.log.info(hql)
self.run_cli(hql)
hql = f"LOAD DATA LOCAL INPATH '{filepath}' "
if overwrite:
hql += "OVERWRITE "
hql += f"INTO TABLE {table} "
if partition:
pvals = ", ".join(f"{k}='{v}'" for k, v in partition.items())
hql += f"PARTITION ({pvals})"
# As a workaround for HIVE-10541, add a newline character
# at the end of hql (AIRFLOW-2412).
hql += ';\n'
self.log.info(hql)
self.run_cli(hql)
def kill(self) -> None:
"""Kill Hive cli command"""
if hasattr(self, 'sub_process'):
if self.sub_process.poll() is None:
print("Killing the Hive job")
self.sub_process.terminate()
time.sleep(60)
self.sub_process.kill()
class HiveMetastoreHook(BaseHook):
"""
Wrapper to interact with the Hive Metastore
:param metastore_conn_id: reference to the
:ref: `metastore thrift service connection id <howto/connection:hive_metastore>`.
"""
# java short max val
MAX_PART_COUNT = 32767
conn_name_attr = 'metastore_conn_id'
default_conn_name = 'metastore_default'
conn_type = 'hive_metastore'
hook_name = 'Hive Metastore Thrift'
def __init__(self, metastore_conn_id: str = default_conn_name) -> None:
super().__init__()
self.conn = self.get_connection(metastore_conn_id)
self.metastore = self.get_metastore_client()
def __getstate__(self) -> dict[str, Any]:
# This is for pickling to work despite the thrift hive client not
# being picklable
state = dict(self.__dict__)
del state['metastore']
return state
def __setstate__(self, d: dict[str, Any]) -> None:
self.__dict__.update(d)
self.__dict__['metastore'] = self.get_metastore_client()
def get_metastore_client(self) -> Any:
"""Returns a Hive thrift client."""
import hmsclient
from thrift.protocol import TBinaryProtocol
from thrift.transport import TSocket, TTransport
host = self._find_valid_host()
conn = self.conn
if not host:
raise AirflowException("Failed to locate the valid server.")
if 'authMechanism' in conn.extra_dejson:
warnings.warn(
"The 'authMechanism' option is deprecated. Please use 'auth_mechanism'.",
DeprecationWarning,
stacklevel=2,
)
conn.extra_dejson['auth_mechanism'] = conn.extra_dejson['authMechanism']
del conn.extra_dejson['authMechanism']
auth_mechanism = conn.extra_dejson.get('auth_mechanism', 'NOSASL')
if conf.get('core', 'security') == 'kerberos':
auth_mechanism = conn.extra_dejson.get('auth_mechanism', 'GSSAPI')
kerberos_service_name = conn.extra_dejson.get('kerberos_service_name', 'hive')
conn_socket = TSocket.TSocket(host, conn.port)
if conf.get('core', 'security') == 'kerberos' and auth_mechanism == 'GSSAPI':
try:
import saslwrapper as sasl
except ImportError:
import sasl
def sasl_factory() -> sasl.Client:
sasl_client = sasl.Client()
sasl_client.setAttr("host", host)
sasl_client.setAttr("service", kerberos_service_name)
sasl_client.init()
return sasl_client
from thrift_sasl import TSaslClientTransport
transport = TSaslClientTransport(sasl_factory, "GSSAPI", conn_socket)
else:
transport = TTransport.TBufferedTransport(conn_socket)
protocol = TBinaryProtocol.TBinaryProtocol(transport)
return hmsclient.HMSClient(iprot=protocol)
def _find_valid_host(self) -> Any:
conn = self.conn
hosts = conn.host.split(',')
for host in hosts:
host_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.log.info("Trying to connect to %s:%s", host, conn.port)
if host_socket.connect_ex((host, conn.port)) == 0:
self.log.info("Connected to %s:%s", host, conn.port)
host_socket.close()
return host
else:
self.log.error("Could not connect to %s:%s", host, conn.port)
return None
def get_conn(self) -> Any:
return self.metastore
def check_for_partition(self, schema: str, table: str, partition: str) -> bool:
"""
Checks whether a partition exists
:param schema: Name of hive schema (database) @table belongs to
:param table: Name of hive table @partition belongs to
:param partition: Expression that matches the partitions to check for
(eg `a = 'b' AND c = 'd'`)
:rtype: bool
>>> hh = HiveMetastoreHook()
>>> t = 'static_babynames_partitioned'
>>> hh.check_for_partition('airflow', t, "ds='2015-01-01'")
True
"""
with self.metastore as client:
partitions = client.get_partitions_by_filter(
schema, table, partition, HiveMetastoreHook.MAX_PART_COUNT
)
return bool(partitions)
def check_for_named_partition(self, schema: str, table: str, partition_name: str) -> Any:
"""
Checks whether a partition with a given name exists
:param schema: Name of hive schema (database) @table belongs to
:param table: Name of hive table @partition belongs to
:param partition_name: Name of the partitions to check for (eg `a=b/c=d`)
:rtype: bool
>>> hh = HiveMetastoreHook()
>>> t = 'static_babynames_partitioned'
>>> hh.check_for_named_partition('airflow', t, "ds=2015-01-01")
True
>>> hh.check_for_named_partition('airflow', t, "ds=xxx")
False
"""
with self.metastore as client:
return client.check_for_named_partition(schema, table, partition_name)
def get_table(self, table_name: str, db: str = 'default') -> Any:
"""Get a metastore table object
>>> hh = HiveMetastoreHook()
>>> t = hh.get_table(db='airflow', table_name='static_babynames')
>>> t.tableName
'static_babynames'
>>> [col.name for col in t.sd.cols]
['state', 'year', 'name', 'gender', 'num']
"""
if db == 'default' and '.' in table_name:
db, table_name = table_name.split('.')[:2]
with self.metastore as client:
return client.get_table(dbname=db, tbl_name=table_name)
def get_tables(self, db: str, pattern: str = '*') -> Any:
"""Get a metastore table object"""
with self.metastore as client:
tables = client.get_tables(db_name=db, pattern=pattern)
return client.get_table_objects_by_name(db, tables)
def get_databases(self, pattern: str = '*') -> Any:
"""Get a metastore table object"""
with self.metastore as client:
return client.get_databases(pattern)
def get_partitions(self, schema: str, table_name: str, partition_filter: str | None = None) -> list[Any]:
"""
Returns a list of all partitions in a table. Works only
for tables with less than 32767 (java short max val).
For subpartitioned table, the number might easily exceed this.
>>> hh = HiveMetastoreHook()
>>> t = 'static_babynames_partitioned'
>>> parts = hh.get_partitions(schema='airflow', table_name=t)
>>> len(parts)
1
>>> parts
[{'ds': '2015-01-01'}]
"""
with self.metastore as client:
table = client.get_table(dbname=schema, tbl_name=table_name)
if len(table.partitionKeys) == 0:
raise AirflowException("The table isn't partitioned")
else:
if partition_filter:
parts = client.get_partitions_by_filter(
db_name=schema,
tbl_name=table_name,
filter=partition_filter,
max_parts=HiveMetastoreHook.MAX_PART_COUNT,
)
else:
parts = client.get_partitions(
db_name=schema, tbl_name=table_name, max_parts=HiveMetastoreHook.MAX_PART_COUNT
)
pnames = [p.name for p in table.partitionKeys]
return [dict(zip(pnames, p.values)) for p in parts]
@staticmethod
def _get_max_partition_from_part_specs(
part_specs: list[Any], partition_key: str | None, filter_map: dict[str, Any] | None
) -> Any:
"""
Helper method to get max partition of partitions with partition_key
from part specs. key:value pair in filter_map will be used to
filter out partitions.
:param part_specs: list of partition specs.
:param partition_key: partition key name.
:param filter_map: partition_key:partition_value map used for partition filtering,
e.g. {'key1': 'value1', 'key2': 'value2'}.
Only partitions matching all partition_key:partition_value
pairs will be considered as candidates of max partition.
:return: Max partition or None if part_specs is empty.
:rtype: basestring
"""
if not part_specs:
return None
# Assuming all specs have the same keys.
if partition_key not in part_specs[0].keys():
raise AirflowException(f"Provided partition_key {partition_key} is not in part_specs.")
is_subset = None
if filter_map:
is_subset = set(filter_map.keys()).issubset(set(part_specs[0].keys()))
if filter_map and not is_subset:
raise AirflowException(
f"Keys in provided filter_map {', '.join(filter_map.keys())} "
f"are not subset of part_spec keys: {', '.join(part_specs[0].keys())}"
)
candidates = [
p_dict[partition_key]
for p_dict in part_specs
if filter_map is None or all(item in p_dict.items() for item in filter_map.items())
]
if not candidates:
return None
else:
return max(candidates)
def max_partition(
self,
schema: str,
table_name: str,
field: str | None = None,
filter_map: dict[Any, Any] | None = None,
) -> Any:
"""
Returns the maximum value for all partitions with given field in a table.
If only one partition key exist in the table, the key will be used as field.
filter_map should be a partition_key:partition_value map and will be used to
filter out partitions.
:param schema: schema name.
:param table_name: table name.
:param field: partition key to get max partition from.
:param filter_map: partition_key:partition_value map used for partition filtering.
>>> hh = HiveMetastoreHook()
>>> filter_map = {'ds': '2015-01-01'}
>>> t = 'static_babynames_partitioned'
>>> hh.max_partition(schema='airflow',\
... table_name=t, field='ds', filter_map=filter_map)
'2015-01-01'
"""
with self.metastore as client:
table = client.get_table(dbname=schema, tbl_name=table_name)
key_name_set = {key.name for key in table.partitionKeys}
if len(table.partitionKeys) == 1:
field = table.partitionKeys[0].name
elif not field:
raise AirflowException("Please specify the field you want the max value for.")
elif field not in key_name_set:
raise AirflowException("Provided field is not a partition key.")
if filter_map and not set(filter_map.keys()).issubset(key_name_set):
raise AirflowException("Provided filter_map contains keys that are not partition key.")
part_names = client.get_partition_names(
schema, table_name, max_parts=HiveMetastoreHook.MAX_PART_COUNT
)
part_specs = [client.partition_name_to_spec(part_name) for part_name in part_names]
return HiveMetastoreHook._get_max_partition_from_part_specs(part_specs, field, filter_map)
def table_exists(self, table_name: str, db: str = 'default') -> bool:
"""
Check if table exists
>>> hh = HiveMetastoreHook()
>>> hh.table_exists(db='airflow', table_name='static_babynames')
True
>>> hh.table_exists(db='airflow', table_name='does_not_exist')
False
"""
try:
self.get_table(table_name, db)
return True
except Exception:
return False
def drop_partitions(self, table_name, part_vals, delete_data=False, db='default'):
"""
Drop partitions from the given table matching the part_vals input
:param table_name: table name.
:param part_vals: list of partition specs.
:param delete_data: Setting to control if underlying data have to deleted
in addition to dropping partitions.
:param db: Name of hive schema (database) @table belongs to
>>> hh = HiveMetastoreHook()
>>> hh.drop_partitions(db='airflow', table_name='static_babynames',
part_vals="['2020-05-01']")
True
"""
if self.table_exists(table_name, db):
with self.metastore as client:
self.log.info(
"Dropping partition of table %s.%s matching the spec: %s", db, table_name, part_vals
)
return client.drop_partition(db, table_name, part_vals, delete_data)
else:
self.log.info("Table %s.%s does not exist!", db, table_name)
return False
class HiveServer2Hook(DbApiHook):
"""
Wrapper around the pyhive library
Notes:
* the default auth_mechanism is PLAIN, to override it you
can specify it in the ``extra`` of your connection in the UI
* the default for run_set_variable_statements is true, if you
are using impala you may need to set it to false in the
``extra`` of your connection in the UI
:param hiveserver2_conn_id: Reference to the
:ref: `Hive Server2 thrift service connection id <howto/connection:hiveserver2>`.
:param schema: Hive database name.
"""
conn_name_attr = 'hiveserver2_conn_id'
default_conn_name = 'hiveserver2_default'
conn_type = 'hiveserver2'
hook_name = 'Hive Server 2 Thrift'
supports_autocommit = False
def get_conn(self, schema: str | None = None) -> Any:
"""Returns a Hive connection object."""
username: str | None = None
password: str | None = None
db = self.get_connection(self.hiveserver2_conn_id) # type: ignore
if 'authMechanism' in db.extra_dejson:
warnings.warn(
"The 'authMechanism' option is deprecated. Please use 'auth_mechanism'.",
DeprecationWarning,
stacklevel=2,
)
db.extra_dejson['auth_mechanism'] = db.extra_dejson['authMechanism']
del db.extra_dejson['authMechanism']
auth_mechanism = db.extra_dejson.get('auth_mechanism', 'NONE')
if auth_mechanism == 'NONE' and db.login is None:
# we need to give a username
username = 'airflow'
kerberos_service_name = None
if conf.get('core', 'security') == 'kerberos':
auth_mechanism = db.extra_dejson.get('auth_mechanism', 'KERBEROS')
kerberos_service_name = db.extra_dejson.get('kerberos_service_name', 'hive')
# pyhive uses GSSAPI instead of KERBEROS as a auth_mechanism identifier
if auth_mechanism == 'GSSAPI':
self.log.warning(
"Detected deprecated 'GSSAPI' for auth_mechanism for %s. Please use 'KERBEROS' instead",
self.hiveserver2_conn_id, # type: ignore
)
auth_mechanism = 'KERBEROS'
# Password should be set if and only if in LDAP or CUSTOM mode
if auth_mechanism in ('LDAP', 'CUSTOM'):
password = db.password
from pyhive.hive import connect
return connect(
host=db.host,
port=db.port,
auth=auth_mechanism,
kerberos_service_name=kerberos_service_name,
username=db.login or username,
password=password,
database=schema or db.schema or 'default',
)
def _get_results(
self,
sql: str | list[str],
schema: str = 'default',
fetch_size: int | None = None,
hive_conf: Iterable | Mapping | None = None,
) -> Any:
from pyhive.exc import ProgrammingError
if isinstance(sql, str):
sql = [sql]
previous_description = None
with contextlib.closing(self.get_conn(schema)) as conn, contextlib.closing(conn.cursor()) as cur:
cur.arraysize = fetch_size or 1000
# not all query services (e.g. impala AIRFLOW-4434) support the set command
db = self.get_connection(self.hiveserver2_conn_id) # type: ignore
if db.extra_dejson.get('run_set_variable_statements', True):
env_context = get_context_from_env_var()
if hive_conf:
env_context.update(hive_conf)
for k, v in env_context.items():
cur.execute(f"set {k}={v}")
for statement in sql:
cur.execute(statement)
# we only get results of statements that returns
lowered_statement = statement.lower().strip()
if (
lowered_statement.startswith('select')
or lowered_statement.startswith('with')
or lowered_statement.startswith('show')
or (lowered_statement.startswith('set') and '=' not in lowered_statement)
):
description = cur.description
if previous_description and previous_description != description:
message = f'''The statements are producing different descriptions:
Current: {repr(description)}
Previous: {repr(previous_description)}'''
raise ValueError(message)
elif not previous_description:
previous_description = description
yield description
try:
# DB API 2 raises when no results are returned
# we're silencing here as some statements in the list
# may be `SET` or DDL
yield from cur
except ProgrammingError:
self.log.debug("get_results returned no records")
def get_results(
self,
sql: str | list[str],
schema: str = 'default',
fetch_size: int | None = None,
hive_conf: Iterable | Mapping | None = None,
) -> dict[str, Any]:
"""
Get results of the provided hql in target schema.
:param sql: hql to be executed.
:param schema: target schema, default to 'default'.
:param fetch_size: max size of result to fetch.
:param hive_conf: hive_conf to execute alone with the hql.
:return: results of hql execution, dict with data (list of results) and header
:rtype: dict
"""
results_iter = self._get_results(sql, schema, fetch_size=fetch_size, hive_conf=hive_conf)
header = next(results_iter)
results = {'data': list(results_iter), 'header': header}
return results
def to_csv(
self,
sql: str,
csv_filepath: str,
schema: str = 'default',
delimiter: str = ',',
lineterminator: str = '\r\n',
output_header: bool = True,
fetch_size: int = 1000,
hive_conf: dict[Any, Any] | None = None,
) -> None:
"""
Execute hql in target schema and write results to a csv file.
:param sql: hql to be executed.
:param csv_filepath: filepath of csv to write results into.
:param schema: target schema, default to 'default'.
:param delimiter: delimiter of the csv file, default to ','.
:param lineterminator: lineterminator of the csv file.
:param output_header: header of the csv file, default to True.
:param fetch_size: number of result rows to write into the csv file, default to 1000.
:param hive_conf: hive_conf to execute alone with the hql.
"""
results_iter = self._get_results(sql, schema, fetch_size=fetch_size, hive_conf=hive_conf)
header = next(results_iter)
message = None
i = 0
with open(csv_filepath, 'wb') as file:
writer = csv.writer(file, delimiter=delimiter, lineterminator=lineterminator, encoding='utf-8')
try:
if output_header:
self.log.debug('Cursor description is %s', header)
writer.writerow([c[0] for c in header])
for i, row in enumerate(results_iter, 1):
writer.writerow(row)
if i % fetch_size == 0:
self.log.info("Written %s rows so far.", i)
except ValueError as exception:
message = str(exception)
if message:
# need to clean up the file first
os.remove(csv_filepath)
raise ValueError(message)
self.log.info("Done. Loaded a total of %s rows.", i)
def get_records(
self, sql: str | list[str], parameters: Iterable | Mapping | None = None, **kwargs
) -> Any:
"""
Get a set of records from a Hive query. You can optionally pass 'schema' kwarg
which specifies target schema and default to 'default'.
:param sql: hql to be executed.
:param parameters: optional configuration passed to get_results
:return: result of hive execution
:rtype: list
>>> hh = HiveServer2Hook()
>>> sql = "SELECT * FROM airflow.static_babynames LIMIT 100"
>>> len(hh.get_records(sql))
100
"""
schema = kwargs['schema'] if 'schema' in kwargs else 'default'
return self.get_results(sql, schema=schema, hive_conf=parameters)['data']
def get_pandas_df( # type: ignore
self,
sql: str,
schema: str = 'default',
hive_conf: dict[Any, Any] | None = None,
**kwargs,
) -> pandas.DataFrame:
"""
Get a pandas dataframe from a Hive query
:param sql: hql to be executed.
:param schema: target schema, default to 'default'.
:param hive_conf: hive_conf to execute alone with the hql.
:param kwargs: (optional) passed into pandas.DataFrame constructor
:return: result of hive execution
:rtype: DataFrame
>>> hh = HiveServer2Hook()
>>> sql = "SELECT * FROM airflow.static_babynames LIMIT 100"
>>> df = hh.get_pandas_df(sql)
>>> len(df.index)
100
:return: pandas.DateFrame
"""
res = self.get_results(sql, schema=schema, hive_conf=hive_conf)
df = pandas.DataFrame(res['data'], columns=[c[0] for c in res['header']], **kwargs)
return df
相关信息
相关文章
0
赞
热门推荐
-
2、 - 优质文章
-
3、 gate.io
-
8、 golang
-
9、 openharmony
-
10、 Vue中input框自动聚焦