"""A maintenance workflow that you can deploy into Airflow to periodically clean
out the DagRun, TaskInstance, Log, XCom, Job DB and SlaMiss entries to avoid
having too much data in your Airflow MetaStore.
## Authors
The DAG is a fork of [teamclairvoyant repository.](
https://github.com/teamclairvoyant/airflow-maintenance-dags/tree/master/db-cleanup
)
## Usage
1. Update the global variables (SCHEDULE_INTERVAL, DAG_OWNER_NAME,
ALERT_EMAIL_ADDRESSES and ENABLE_DELETE) in the DAG with the desired values
2. Modify the DATABASE_OBJECTS list to add/remove objects as needed. Each
dictionary in the list features the following parameters:
- airflow_db_model: Model imported from airflow.models corresponding to
a table in the airflow metadata database
- age_check_column: Column in the model/table to use for calculating max
date of data deletion
3. Create and Set the following Variables in the Airflow Web Server
(Admin -> Variables)
- airflow_db_cleanup__max_db_entry_age_in_days - integer - Length to
retain the log files if not already provided in the conf. If this is set
to 30, the job will remove those files that are 30 days old or older.
4. Put the DAG in your gcs bucket.
"""
from datetime import timedelta
import logging
import os
import airflow
from airflow import settings
from airflow.models import (
DAG,
DagModel,
DagRun,
Log,
SlaMiss,
TaskInstance,
Variable,
XCom,
)
from airflow.operators.python import PythonOperator
from airflow.utils import timezone
from airflow.version import version as airflow_version
import dateutil.parser
from sqlalchemy import desc, text
from sqlalchemy.exc import ProgrammingError
def parse_airflow_version(version: str) -> tuple[int]:
# TODO(developer): Update this function if you are using a version
# with non-numerical characters such as "2.9.3rc1".
COMPOSER_SUFFIX = "+composer"
if version.endswith(COMPOSER_SUFFIX):
airflow_version_without_suffix = version[:-len(COMPOSER_SUFFIX)]
else:
airflow_version_without_suffix = version
airflow_version_str = airflow_version_without_suffix.split(".")
return tuple([int(s) for s in airflow_version_str])
now = timezone.utcnow
# airflow-db-cleanup
DAG_ID = os.path.basename(__file__).replace(".pyc", "").replace(".py", "")
START_DATE = airflow.utils.dates.days_ago(1)
# How often to Run. @daily - Once a day at Midnight (UTC).
SCHEDULE_INTERVAL = "@daily"
# Who is listed as the owner of this DAG in the Airflow Web Server.
DAG_OWNER_NAME = "operations"
# List of email address to send email alerts to if this job fails.
ALERT_EMAIL_ADDRESSES = []
# Airflow version used by the environment as a tuple of integers.
# For example: (2, 9, 2)
#
# Value in `airflow_version` is in format e.g. "2.9.2+composer"
# It's converted to facilitate version comparison.
AIRFLOW_VERSION = parse_airflow_version(airflow_version)
# Length to retain the log files if not already provided in the configuration.
# If this is set to 30, the job will remove those files
# that are 30 days old or older.
DEFAULT_MAX_DB_ENTRY_AGE_IN_DAYS = int(
Variable.get("airflow_db_cleanup__max_db_entry_age_in_days", 30)
)
# Prints the database entries which will be getting deleted;
# set to False to avoid printing large lists and slowdown the process.
PRINT_DELETES = False
# Whether the job should delete the DB entries or not.
# Included if you want to temporarily avoid deleting the DB entries.
ENABLE_DELETE = True
# List of all the objects that will be deleted.
# Comment out the DB objects you want to skip.
DATABASE_OBJECTS = [
{
"airflow_db_model": DagRun,
"age_check_column": DagRun.execution_date,
"keep_last": True,
"keep_last_filters": [DagRun.external_trigger.is_(False)],
"keep_last_group_by": DagRun.dag_id,
},
{
"airflow_db_model": TaskInstance,
"age_check_column": TaskInstance.start_date,
"keep_last": False,
"keep_last_filters": None,
"keep_last_group_by": None,
},
{
"airflow_db_model": Log,
"age_check_column": Log.dttm,
"keep_last": False,
"keep_last_filters": None,
"keep_last_group_by": None,
},
{
"airflow_db_model": XCom,
"age_check_column": XCom.execution_date
if AIRFLOW_VERSION < (2, 2, 5)
else XCom.timestamp,
"keep_last": False,
"keep_last_filters": None,
"keep_last_group_by": None,
},
{
"airflow_db_model": SlaMiss,
"age_check_column": SlaMiss.execution_date,
"keep_last": False,
"keep_last_filters": None,
"keep_last_group_by": None,
},
{
"airflow_db_model": DagModel,
"age_check_column": DagModel.last_parsed_time,
"keep_last": False,
"keep_last_filters": None,
"keep_last_group_by": None,
},
]
# Check for TaskReschedule model.
try:
from airflow.models import TaskReschedule
DATABASE_OBJECTS.append(
{
"airflow_db_model": TaskReschedule,
"age_check_column": TaskReschedule.execution_date
if AIRFLOW_VERSION < (2, 2, 0)
else TaskReschedule.start_date,
"keep_last": False,
"keep_last_filters": None,
"keep_last_group_by": None,
}
)
except Exception as e:
logging.error(e)
# Check for TaskFail model.
try:
from airflow.models import TaskFail
DATABASE_OBJECTS.append(
{
"airflow_db_model": TaskFail,
"age_check_column": TaskFail.start_date,
"keep_last": False,
"keep_last_filters": None,
"keep_last_group_by": None,
}
)
except Exception as e:
logging.error(e)
# Check for RenderedTaskInstanceFields model.
if AIRFLOW_VERSION < (2, 4, 0):
try:
from airflow.models import RenderedTaskInstanceFields
DATABASE_OBJECTS.append(
{
"airflow_db_model": RenderedTaskInstanceFields,
"age_check_column": RenderedTaskInstanceFields.execution_date,
"keep_last": False,
"keep_last_filters": None,
"keep_last_group_by": None,
}
)
except Exception as e:
logging.error(e)
# Check for ImportError model.
try:
from airflow.models import ImportError
DATABASE_OBJECTS.append(
{
"airflow_db_model": ImportError,
"age_check_column": ImportError.timestamp,
"keep_last": False,
"keep_last_filters": None,
"keep_last_group_by": None,
"do_not_delete_by_dag_id": True,
}
)
except Exception as e:
logging.error(e)
if AIRFLOW_VERSION < (2, 6, 0):
try:
from airflow.jobs.base_job import BaseJob
DATABASE_OBJECTS.append(
{
"airflow_db_model": BaseJob,
"age_check_column": BaseJob.latest_heartbeat,
"keep_last": False,
"keep_last_filters": None,
"keep_last_group_by": None,
}
)
except Exception as e:
logging.error(e)
else:
try:
from airflow.jobs.job import Job
DATABASE_OBJECTS.append(
{
"airflow_db_model": Job,
"age_check_column": Job.latest_heartbeat,
"keep_last": False,
"keep_last_filters": None,
"keep_last_group_by": None,
}
)
except Exception as e:
logging.error(e)
default_args = {
"owner": DAG_OWNER_NAME,
"depends_on_past": False,
"email": ALERT_EMAIL_ADDRESSES,
"email_on_failure": True,
"email_on_retry": False,
"start_date": START_DATE,
"retries": 1,
"retry_delay": timedelta(minutes=1),
}
dag = DAG(
DAG_ID,
default_args=default_args,
schedule_interval=SCHEDULE_INTERVAL,
start_date=START_DATE,
)
if hasattr(dag, "doc_md"):
dag.doc_md = __doc__
if hasattr(dag, "catchup"):
dag.catchup = False
def print_configuration_function(**context):
logging.info("Loading Configurations...")
dag_run_conf = context.get("dag_run").conf
logging.info("dag_run.conf: " + str(dag_run_conf))
max_db_entry_age_in_days = None
if dag_run_conf:
max_db_entry_age_in_days = dag_run_conf.get(
"maxDBEntryAgeInDays", None
)
logging.info("maxDBEntryAgeInDays from dag_run.conf: " + str(dag_run_conf))
if max_db_entry_age_in_days is None or max_db_entry_age_in_days < 1:
logging.info(
"maxDBEntryAgeInDays conf variable isn't included or Variable "
+ "value is less than 1. Using Default '"
+ str(DEFAULT_MAX_DB_ENTRY_AGE_IN_DAYS)
+ "'"
)
max_db_entry_age_in_days = DEFAULT_MAX_DB_ENTRY_AGE_IN_DAYS
max_date = now() + timedelta(-max_db_entry_age_in_days)
logging.info("Finished Loading Configurations")
logging.info("")
logging.info("Configurations:")
logging.info("max_db_entry_age_in_days: " + str(max_db_entry_age_in_days))
logging.info("max_date: " + str(max_date))
logging.info("enable_delete: " + str(ENABLE_DELETE))
logging.info("")
logging.info("Setting max_execution_date to XCom for Downstream Processes")
context["ti"].xcom_push(key="max_date", value=max_date.isoformat())
print_configuration = PythonOperator(
task_id="print_configuration",
python_callable=print_configuration_function,
provide_context=True,
dag=dag,
)
def build_query(
session,
airflow_db_model,
age_check_column,
max_date,
dag_id=None
):
"""
Build a database query to retrieve and filter Airflow data.
Args:
session: SQLAlchemy session object for database interaction.
airflow_db_model: The Airflow model class to query (e.g., DagRun).
age_check_column: The column representing the age of the data.
max_date: The maximum allowed age for the data.
dag_id (optional): The ID of the DAG to filter by. Defaults to None.
Returns:
SQLAlchemy query object: The constructed query.
"""
query = session.query(airflow_db_model)
logging.info("INITIAL QUERY : " + str(query))
if dag_id:
query = query.filter(airflow_db_model.dag_id == dag_id)
if airflow_db_model == DagRun:
newest_dagrun = (
session
.query(airflow_db_model)
.filter(DagRun.external_trigger.is_(False))
.filter(airflow_db_model.dag_id == dag_id)
.order_by(desc(airflow_db_model.execution_date))
.first()
)
logging.info("Newest dagrun: " + str(newest_dagrun))
# For DagRuns we want to leave last *scheduled* DagRun
# regardless of its age, otherwise Airflow will retrigger it
if newest_dagrun is not None:
query = (
query
.filter(airflow_db_model.id != newest_dagrun.id)
)
query = query.filter(age_check_column <= max_date)
logging.info("FINAL QUERY: " + str(query))
return query
def print_query(query, airflow_db_model, age_check_column):
entries_to_delete = query.all()
logging.info("Query: " + str(query))
logging.info(
"Process will be Deleting the following "
+ str(airflow_db_model.__name__)
+ "(s):"
)
for entry in entries_to_delete:
date = str(entry.__dict__[str(age_check_column).split(".")[1]])
logging.info("\tEntry: " + str(entry) + ", Date: " + date)
logging.info(
"Process will be Deleting "
+ str(len(entries_to_delete))
+ " "
+ str(airflow_db_model.__name__)
+ "(s)"
)
def cleanup_function(**context):
session = settings.Session()
logging.info("Retrieving max_execution_date from XCom")
max_date = context["ti"].xcom_pull(
task_ids=print_configuration.task_id, key="max_date"
)
max_date = dateutil.parser.parse(max_date) # stored as iso8601 str in xcom
airflow_db_model = context["params"].get("airflow_db_model")
state = context["params"].get("state")
age_check_column = context["params"].get("age_check_column")
keep_last = context["params"].get("keep_last")
keep_last_filters = context["params"].get("keep_last_filters")
keep_last_group_by = context["params"].get("keep_last_group_by")
logging.info("Configurations:")
logging.info("max_date: " + str(max_date))
logging.info("enable_delete: " + str(ENABLE_DELETE))
logging.info("session: " + str(session))
logging.info("airflow_db_model: " + str(airflow_db_model))
logging.info("state: " + str(state))
logging.info("age_check_column: " + str(age_check_column))
logging.info("keep_last: " + str(keep_last))
logging.info("keep_last_filters: " + str(keep_last_filters))
logging.info("keep_last_group_by: " + str(keep_last_group_by))
logging.info("")
logging.info("Running Cleanup Process...")
try:
if context["params"].get("do_not_delete_by_dag_id"):
query = build_query(
session=session,
airflow_db_model=airflow_db_model,
age_check_column=age_check_column,
max_date=max_date,
)
if PRINT_DELETES:
print_query(query, airflow_db_model, age_check_column)
if ENABLE_DELETE:
logging.info("Performing Delete...")
query.delete(synchronize_session=False)
session.commit()
else:
dags = session.query(airflow_db_model.dag_id).distinct()
session.commit()
list_dags = [str(list(dag)[0]) for dag in dags] + [None]
for dag_id in list_dags:
query = build_query(
session=session,
airflow_db_model=airflow_db_model,
age_check_column=age_check_column,
max_date=max_date,
dag_id=dag_id,
)
if PRINT_DELETES:
print_query(query, airflow_db_model, age_check_column)
if ENABLE_DELETE:
logging.info("Performing Delete...")
query.delete(synchronize_session=False)
session.commit()
if not ENABLE_DELETE:
logging.warning(
"You've opted to skip deleting the db entries. "
"Set ENABLE_DELETE to True to delete entries!!!"
)
logging.info("Finished Running Cleanup Process")
except ProgrammingError as e:
logging.error(e)
logging.error(
str(airflow_db_model) +
" is not present in the metadata." +
"Skipping..."
)
finally:
session.close()
def cleanup_sessions():
session = settings.Session()
try:
logging.info("Deleting sessions...")
count_statement = (
"SELECT COUNT(*) AS cnt FROM session " +
"WHERE expiry < now()::timestamp(0);"
)
before = session.execute(text(count_statement)).one_or_none()["cnt"]
session.execute(
text(
"DELETE FROM session WHERE expiry < now()::timestamp(0);"
)
)
after = session.execute(text(count_statement)).one_or_none()["cnt"]
logging.info("Deleted %s expired sessions.", (before - after))
except Exception as err:
logging.exception(err)
session.commit()
session.close()
def analyze_db():
session = settings.Session()
session.execute("ANALYZE")
session.commit()
session.close()
analyze_op = PythonOperator(
task_id="analyze_query",
python_callable=analyze_db,
provide_context=True,
dag=dag
)
cleanup_session_op = PythonOperator(
task_id="cleanup_sessions",
python_callable=cleanup_sessions,
provide_context=True,
dag=dag,
)
cleanup_session_op.set_downstream(analyze_op)
for db_object in DATABASE_OBJECTS:
cleanup_op = PythonOperator(
task_id="cleanup_" + str(db_object["airflow_db_model"].__name__),
python_callable=cleanup_function,
params=db_object,
provide_context=True,
dag=dag,
)
print_configuration.set_downstream(cleanup_op)
cleanup_op.set_downstream(analyze_op)
