YingboWang commented on a change in pull request #5499: URL: https://github.com/apache/airflow/pull/5499#discussion_r472571844
########## File path: airflow/sensors/smart_sensor_operator.py ########## @@ -0,0 +1,764 @@ +# +# 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. + + +import datetime +import json +import logging +import time +import traceback +from logging.config import DictConfigurator # type: ignore +from time import sleep + +from sqlalchemy import and_, or_, tuple_ + +from airflow.exceptions import AirflowException, AirflowTaskTimeout +from airflow.models import BaseOperator, SensorInstance, SkipMixin, TaskInstance +from airflow.settings import LOGGING_CLASS_PATH +from airflow.stats import Stats +from airflow.utils import helpers, timezone +from airflow.utils.decorators import apply_defaults +from airflow.utils.email import send_email +from airflow.utils.log.logging_mixin import set_context +from airflow.utils.module_loading import import_string +from airflow.utils.net import get_hostname +from airflow.utils.session import provide_session +from airflow.utils.state import PokeState, State +from airflow.utils.timeout import timeout + +config = import_string(LOGGING_CLASS_PATH) +handler_config = config['handlers']['task'] +try: + formatter_config = config['formatters'][handler_config['formatter']] +except Exception as err: # pylint: disable=broad-except + formatter_config = None + print(err) +dictConfigurator = DictConfigurator(config) + + +class SensorWork: + """ + This class stores a sensor work with decoded context value. It is only used + inside of smart sensor. Create a sensor work based on sensor instance record. + A sensor work object has the following attributes: + `dag_id`: sensor_instance dag_id. + `task_id`: sensor_instance task_id. + `execution_date`: sensor_instance execution_date. + `try_number`: sensor_instance try_number + `poke_context`: Decoded poke_context for the sensor task. + `execution_context`: Decoded execution_context. + `hashcode`: This is the signature of poking job. + `operator`: The sensor operator class. + `op_classpath`: The sensor operator class path + `encoded_poke_context`: The raw data from sensor_instance poke_context column. + `log`: The sensor work logger which will mock the corresponding task instance log. + + :param si: The sensor_instance ORM object. + """ + def __init__(self, si): + self.dag_id = si.dag_id + self.task_id = si.task_id + self.execution_date = si.execution_date + self.try_number = si.try_number + + self.poke_context = json.loads(si.poke_context) if si.poke_context else {} + self.execution_context = json.loads(si.execution_context) if si.execution_context else {} + try: + self.log = self._get_sensor_logger(si) + except Exception as e: # pylint: disable=broad-except + self.log = None + print(e) + self.hashcode = si.hashcode + self.start_date = si.start_date + self.operator = si.operator + self.op_classpath = si.op_classpath + self.encoded_poke_context = si.poke_context + + def __eq__(self, other): + if not isinstance(other, SensorWork): + return NotImplemented + + return self.dag_id == other.dag_id and \ + self.task_id == other.task_id and \ + self.execution_date == other.execution_date and \ + self.try_number == other.try_number + + @staticmethod + def create_new_task_handler(): + """ + Create task log handler for a sensor work. + :return: log handler + """ + handler_config_copy = {k: handler_config[k] for k in handler_config} + formatter_config_copy = {k: formatter_config[k] for k in formatter_config} + handler = dictConfigurator.configure_handler(handler_config_copy) + formatter = dictConfigurator.configure_formatter(formatter_config_copy) + handler.setFormatter(formatter) + return handler + + def _get_sensor_logger(self, si): + """ + Return logger for a sensor instance object. + """ + # The created log_id is used inside of smart sensor as the key to fetch + # the corresponding in memory log handler. + si.raw = False # Otherwise set_context will fail + log_id = "-".join([si.dag_id, + si.task_id, + si.execution_date.strftime("%Y_%m_%dT%H_%M_%S_%f"), + str(si.try_number)]) + logger = logging.getLogger('airflow.task' + '.' + log_id) + + if len(logger.handlers) == 0: + handler = self.create_new_task_handler() + logger.addHandler(handler) + set_context(logger, si) + + line_break = ("-" * 120) + logger.info(line_break) + logger.info("Processing sensor task %s in smart sensor service on host: %s", + self.ti_key, get_hostname()) + logger.info(line_break) + return logger + + def close_sensor_logger(self): + """ + Close log handler for a sensor work. + """ + for handler in self.log.handlers: + try: + handler.close() + except Exception as e: # pylint: disable=broad-except + print(e) + + @property + def ti_key(self): + """ + Key for the task instance that maps to the sensor work. + """ + return self.dag_id, self.task_id, self.execution_date + + @property + def cache_key(self): + """ + Key used to query in smart sensor for cached sensor work. + """ + return self.operator, self.encoded_poke_context + + +class CachedPokeWork: + """ + Wrapper class for the poke work inside smart sensor. It saves + the sensor_task used to poke and recent poke result state. + state: poke state. + sensor_task: The cached object for executing the poke function. + last_poke_time: The latest time this cached work being called. + to_flush: If we should flush the cached work. + """ + def __init__(self): + self.state = None + self.sensor_task = None + self.last_poke_time = None + self.to_flush = False + + def set_state(self, state): + """ + Set state for cached poke work. + :param state: The sensor_instance state. + """ + self.state = state + self.last_poke_time = timezone.utcnow() + + def clear_state(self): + """ + Clear state for cached poke work. + """ + self.state = None + + def set_to_flush(self): + """ + Mark this poke work to be popped from cached dict after current loop. + """ + self.to_flush = True + + def is_expired(self): + """ + The cached task object expires if there is no poke for 20 minutes. + :return: Boolean + """ + return self.to_flush or (timezone.utcnow() - self.last_poke_time).total_seconds() > 1200 + + +class SensorExceptionInfo: + """ + Hold sensor exception information and the type of exception. For possible transient + infra failure, give the task more chance to retry before fail it. + """ + def __init__(self, + exception_info, + is_infra_failure=False, + infra_failure_retry_window=datetime.timedelta(minutes=130)): + self._exception_info = exception_info + self._is_infra_failure = is_infra_failure + self._infra_failure_retry_window = infra_failure_retry_window + + self._infra_failure_timeout = None + self.set_infra_failure_timeout() + self.fail_current_run = self.should_fail_current_run() + + def set_latest_exception(self, exception_info, is_infra_failure=False): + """ + This function set the latest exception information for sensor exception. If the exception + implies an infra failure, this function will check the recorded infra failure timeout + which was set at the first infra failure exception arrives. There is a 6 hours window + for retry without failing current run. + + :param exception_info: Details of the exception information. + :param is_infra_failure: If current exception was caused by transient infra failure. + There is a retry window _infra_failure_retry_window that the smart sensor will + retry poke function without failing current task run. + """ + self._exception_info = exception_info + self._is_infra_failure = is_infra_failure + + self.set_infra_failure_timeout() + self.fail_current_run = self.should_fail_current_run() + + def set_infra_failure_timeout(self): + """ + Set the time point when the sensor should be failed if it kept getting infra + failure. + :return: + """ + # Only set the infra_failure_timeout if there is no existing one + if not self._is_infra_failure: + self._infra_failure_timeout = None + elif self._infra_failure_timeout is None: + self._infra_failure_timeout = timezone.utcnow() + self._infra_failure_retry_window + + def should_fail_current_run(self): + """ + :return: Should the sensor fail + :type: boolean + """ + return not self.is_infra_failure or timezone.utcnow() > self._infra_failure_timeout + + @property + def exception_info(self): + """ + :return: exception msg. + """ + return self._exception_info + + @property + def is_infra_failure(self): + """ + + :return: If the exception is an infra failure + :type: boolean + """ + return self._is_infra_failure + + def is_expired(self): + """ + :return: If current exception need to be kept. + :type: boolean + """ + if not self._is_infra_failure: + return True + return timezone.utcnow() > self._infra_failure_timeout + datetime.timedelta(minutes=30) + + +class SmartSensorOperator(BaseOperator, SkipMixin): + """ + Smart sensor operators are derived from this class. + + Smart Sensor operators keep refresh a dictionary by visiting DB. + Taking qualified active sensor tasks. Different from sensor operator, + Smart sensor operators poke for all sensor tasks in the dictionary at + a time interval. When a criteria is met or fail by time out, it update + all sensor task state in task_instance table + + :param soft_fail: Set to true to mark the task as SKIPPED on failure + :type soft_fail: bool + :param poke_interval: Time in seconds that the job should wait in + between each tries. + :type poke_interval: int + :param smart_sensor_timeout: Time, in seconds before the internal sensor + job times out if poke_timeout is not defined. + :type smart_sensor_timeout: int + :param shard_min: shard code lower bound (inclusive) + :type shard_min: int + :param shard_max: shard code upper bound (exclusive) + :type shard_max: int + :param poke_exception_cache_ttl: Time, in seconds before the current + exception expires and being cleaned up. + :type poke_exception_cache_ttl: int + :param poke_timeout: Time, in seconds before the task times out and fails. + :type poke_timeout: int + """ + ui_color = '#e6f1f2' + + @apply_defaults + def __init__(self, + poke_interval=180, + smart_sensor_timeout=60 * 60 * 24 * 7, + soft_fail=False, + shard_min=0, + shard_max=100000, + poke_exception_cache_ttl=600, + poke_timeout=6, + *args, + **kwargs): + super().__init__(*args, **kwargs) + # super(SmartSensorOperator, self).__init__(*args, **kwargs) + self.poke_interval = poke_interval + self.soft_fail = soft_fail + self.timeout = smart_sensor_timeout + self._validate_input_values() + self.hostname = "" + + self.sensor_works = [] + self.cached_dedup_works = {} + self.cached_sensor_exceptions = {} + + self.max_tis_per_query = 50 + self.shard_min = shard_min + self.shard_max = shard_max + self.poke_exception_cache_ttl = poke_exception_cache_ttl + self.poke_timeout = poke_timeout + + def _validate_input_values(self): + if not isinstance(self.poke_interval, (int, float)) or self.poke_interval < 0: + raise AirflowException( + "The poke_interval must be a non-negative number") + if not isinstance(self.timeout, (int, float)) or self.timeout < 0: + raise AirflowException( + "The timeout must be a non-negative number") + + @provide_session + def _load_sensor_works(self, session=None): + """ + Refresh sensor instances need to be handled by this operator. Create smart sensor + internal object based on the information persisted in the sensor_instance table. + + """ + SI = SensorInstance + start_query_time = time.time() + query = session.query(SI) \ + .filter(SI.state == State.SENSING)\ + .filter(SI.shardcode < self.shard_max, + SI.shardcode >= self.shard_min) + tis = query.all() + + self.log.info("Performance query %s tis, time: %s", len(tis), time.time() - start_query_time) + + # Query without checking dagrun state might keep some failed dag_run tasks alive. + # Join with DagRun table will be very slow based on the number of sensor tasks we + # need to handle. We query all smart tasks in this operator + # and expect scheduler correct the states in _change_state_for_tis_without_dagrun() + + sensor_works = [] + for ti in tis: + try: + sensor_works.append(SensorWork(ti)) + except Exception as e: # pylint: disable=broad-except + self.log.exception("Exception at creating sensor work for ti %s", ti.key) + self.log.exception(e, exc_info=True) + + self.log.info("%d tasks detected.", len(sensor_works)) + + new_sensor_works = [x for x in sensor_works if x not in self.sensor_works] + + self._update_ti_hostname(new_sensor_works) + + self.sensor_works = sensor_works + + @provide_session + def _update_ti_hostname(self, sensor_works, session=None): + """ + Update task instance hostname for new sensor works. + + :param sensor_works: Smart sensor internal object for a sensor task. + :param session: The sqlalchemy session. + """ + TI = TaskInstance + ti_keys = [(x.dag_id, x.task_id, x.execution_date) for x in sensor_works] + + def update_ti_hostname_with_count(count, ti_keys): + # Using or_ instead of in_ here to prevent from full table scan. + tis = session.query(TI) \ + .filter(or_(tuple_(TI.dag_id, TI.task_id, TI.execution_date) == ti_key + for ti_key in ti_keys)) \ + .all() + + for ti in tis: + ti.hostname = self.hostname + session.commit() + + return count + len(ti_keys) + + count = helpers.reduce_in_chunks(update_ti_hostname_with_count, ti_keys, 0, self.max_tis_per_query) + if count: + self.log.info("Updated hostname on %s tis.", count) + + @provide_session + def _mark_multi_state(self, operator, poke_hash, encoded_poke_context, state, session=None): + """ + Mark state for multiple tasks in the task_instance table to a new state if they have + the same signature as the poke_hash. + + :param operator: The sensor's operator class name. + :param poke_hash: The hash code generated from sensor's poke context. + :param encoded_poke_context: The raw encoded poke_context. + :param state: Set multiple sensor tasks to this state. + :param session: The sqlalchemy session. + """ + def mark_state(ti, sensor_instance): + ti.state = state + sensor_instance.state = state + if state in State.finished(): + ti.end_date = end_date + ti.set_duration() + + SI = SensorInstance + TI = TaskInstance + + count_marked = 0 + try: + query_result = session.query(TI, SI)\ + .join(TI, and_(TI.dag_id == SI.dag_id, + TI.task_id == SI.task_id, + TI.execution_date == SI.execution_date)) \ + .filter(SI.state == State.SENSING) \ + .filter(SI.hashcode == poke_hash) \ + .filter(SI.operator == operator) \ + .with_for_update().all() + + end_date = timezone.utcnow() + for ti, sensor_instance in query_result: + if sensor_instance.poke_context != encoded_poke_context: + continue + + ti.hostname = self.hostname + if ti.state == State.SENSING: + mark_state(ti=ti, sensor_instance=sensor_instance) + count_marked += 1 + else: + # ti.state != State.SENSING + sensor_instance.state = ti.state + + session.commit() + + except Exception as e: # pylint: disable=broad-except + self.log.warning("Exception _mark_multi_state in smart sensor for hashcode %s", + str(poke_hash)) + self.log.exception(e, exc_info=True) + self.log.info("Marked %s tasks out of %s to state %s", count_marked, len(query_result), state) + + @provide_session + def _retry_or_fail_task(self, sensor_work, error, session=None): + """ + Change single task state for sensor task. For final state, set the end_date. + Since smart sensor take care all retries in one process. Failed sensor tasks + logically experienced all retries and the try_number should be set to max_tries. + + :param sensor_work: The sensor_work with exception. + :type sensor_work: SensorWork + :param error: The error message for this sensor_work. + :type error: str. + :param session: The sqlalchemy session. + """ + def email_alert(task_instance, error_info): + try: + subject, html_content, _ = task_instance.get_email_subject_content(error_info) + email = sensor_work.execution_context.get('email') + + send_email(email, subject, html_content) + except Exception as e: # pylint: disable=broad-except + sensor_work.log.warning("Exception alerting email.") + sensor_work.log.exception(e, exc_info=True) + + def handle_failure(sensor_work, ti): + if sensor_work.execution_context.get('retries', None) and \ + ti.try_number <= ti.max_tries: + # retry + ti.state = State.UP_FOR_RETRY + if sensor_work.execution_context.get('email_on_retry', None) and \ + sensor_work.execution_context.get('email', None): + sensor_work.log.info("%s sending email alert for retry", sensor_work.ti_key) + email_alert(ti, error) + else: + ti.state = State.FAILED + if sensor_work.execution_context.get('email_on_failure', None) and \ + sensor_work.execution_context.get('email', None): + sensor_work.log.info("%s sending email alert for failure", sensor_work.ti_key) + email_alert(ti, error) + + try: + dag_id, task_id, execution_date = sensor_work.ti_key + TI = TaskInstance + SI = SensorInstance + sensor_instance = session.query(SI).filter( + SI.dag_id == dag_id, + SI.task_id == task_id, + SI.execution_date == execution_date) \ + .with_for_update() \ + .first() + + if sensor_instance.hashcode != sensor_work.hashcode: + # Return without setting state + return + + ti = session.query(TI).filter( + TI.dag_id == dag_id, + TI.task_id == task_id, + TI.execution_date == execution_date) \ + .with_for_update() \ + .first() + + if ti: + if ti.state == State.SENSING: + ti.hostname = self.hostname + handle_failure(sensor_work, ti) + + sensor_instance.state = State.FAILED + ti.end_date = timezone.utcnow() + ti.set_duration() + else: + sensor_instance.state = ti.state + session.merge(sensor_instance) + session.merge(ti) + session.commit() + + sensor_work.log.info("Task %s got an error: %s. Set the state to failed. Exit.", + str(sensor_work.ti_key), error) + sensor_work.close_sensor_logger() + + except AirflowException as e: + sensor_work.log.warning("Exception on failing %s", sensor_work.ti_key) + sensor_work.log.exception(e, exc_info=True) + + def _check_and_handle_ti_timeout(self, sensor_work): + """ + Check if a sensor task in smart sensor is timeout. Could be either sensor operator timeout + or general operator execution_timeout. + + :param sensor_work: SensorWork + """ + task_timeout = sensor_work.execution_context.get('timeout', self.timeout) + task_execution_timeout = sensor_work.execution_context.get('execution_timeout', None) + if task_execution_timeout: + task_timeout = min(task_timeout, task_execution_timeout) + + if (timezone.utcnow() - sensor_work.start_date).total_seconds() > task_timeout: + error = "Sensor Timeout" + sensor_work.log.exception(error) + self._retry_or_fail_task(sensor_work, error) + + def _handle_poke_exception(self, sensor_work): + """ + Fail task if accumulated exceptions exceeds retries. + + :param sensor_work: SensorWork + """ + sensor_exception = self.cached_sensor_exceptions.get(sensor_work.cache_key) + error = sensor_exception.exception_info + sensor_work.log.exception("Handling poke exception: %s", error) + + if sensor_exception.fail_current_run: + if sensor_exception.is_infra_failure: + sensor_work.log.exception("Task %s failed by infra failure in smart sensor.", + sensor_work.ti_key) + # There is a risk for sensor object cached in smart sensor keep throwing + # exception and cause an infra failure. To make sure the sensor tasks after + # retry will not fall into same object and have endless infra failure, + # we mark the sensor task after an infra failure so that it can be popped + # before next poke loop. + cache_key = sensor_work.cache_key + self.cached_dedup_works[cache_key].set_to_flush() + else: + sensor_work.log.exception("Task %s failed by exceptions.", sensor_work.ti_key) + self._retry_or_fail_task(sensor_work, error) + else: + sensor_work.log.info("Exception detected, retrying without failing current run.") + self._check_and_handle_ti_timeout(sensor_work) + + def _process_sensor_work_with_cached_state(self, sensor_work, state): + if state == PokeState.LANDED: + sensor_work.log.info("Task %s succeeded", str(sensor_work.ti_key)) + sensor_work.close_sensor_logger() + + if state == PokeState.NOT_LANDED: + # Handle timeout if connection valid but not landed yet + self._check_and_handle_ti_timeout(sensor_work) + elif state == PokeState.POKE_EXCEPTION: + self._handle_poke_exception(sensor_work) + + def _execute_sensor_work(self, sensor_work): + ti_key = sensor_work.ti_key + log = sensor_work.log or self.log + log.info("Sensing ti: %s", str(ti_key)) + log.info("Poking with arguments: %s", sensor_work.encoded_poke_context) + + cache_key = sensor_work.cache_key + if cache_key not in self.cached_dedup_works: + # create an empty cached_work for a new cache_key + self.cached_dedup_works[cache_key] = CachedPokeWork() + + cached_work = self.cached_dedup_works[cache_key] + + if cached_work.state is not None: + # Have a valid cached state, don't poke twice in certain time interval + self._process_sensor_work_with_cached_state(sensor_work, cached_work.state) + return + + try: + with timeout(seconds=self.poke_timeout): + if self.poke(sensor_work): + # Got a landed signal, mark all tasks waiting for this partition + cached_work.set_state(PokeState.LANDED) + + self._mark_multi_state(sensor_work.operator, + sensor_work.hashcode, + sensor_work.encoded_poke_context, + State.SUCCESS) + + log.info("Task %s succeeded", str(ti_key)) + sensor_work.close_sensor_logger() + else: + # Not landed yet. Handle possible timeout + cached_work.set_state(PokeState.NOT_LANDED) + self._check_and_handle_ti_timeout(sensor_work) + + self.cached_sensor_exceptions.pop(cache_key, None) + except Exception as e: # pylint: disable=broad-except + # The retry_infra_failure decorator inside hive_hooks will raise exception with + # is_infra_failure == True. Long poking timeout here is also considered an infra + # failure. Other exceptions should fail. + is_infra_failure = getattr(e, 'is_infra_failure', False) or isinstance(e, AirflowTaskTimeout) + exception_info = traceback.format_exc() + cached_work.set_state(PokeState.POKE_EXCEPTION) + + if cache_key in self.cached_sensor_exceptions: + self.cached_sensor_exceptions[cache_key].set_latest_exception( + exception_info, + is_infra_failure=is_infra_failure) + else: + self.cached_sensor_exceptions[cache_key] = SensorExceptionInfo( + exception_info, + is_infra_failure=is_infra_failure) + + self._handle_poke_exception(sensor_work) + + def flush_cached_sensor_poke_results(self): + """ + Flush outdated cached sensor states saved in previous loop. + + """ + for key, cached_work in self.cached_dedup_works.items(): + if cached_work.is_expired(): + self.cached_dedup_works.pop(key, None) + else: + cached_work.state = None + + for ti_key, sensor_exception in self.cached_sensor_exceptions.items(): + if sensor_exception.fail_current_run or sensor_exception.is_expired(): + self.cached_sensor_exceptions.pop(ti_key, None) + + def poke(self, sensor_work): + """ + Function that the sensors defined while deriving this class should + override. + + """ + cached_work = self.cached_dedup_works[sensor_work.cache_key] + if not cached_work.sensor_task: + init_args = dict(list(sensor_work.poke_context.items()) + + [('task_id', sensor_work.task_id)]) + operator_class = import_string(sensor_work.op_classpath) + cached_work.sensor_task = operator_class(**init_args) + + return cached_work.sensor_task.poke(sensor_work.poke_context) + + def _emit_loop_stats(self): + try: + count_poke = 0 + count_poke_success = 0 + count_poke_exception = 0 + count_exception_failures = 0 + count_infra_failure = 0 + for cached_work in self.cached_dedup_works.values(): + if cached_work.state is None: + continue + count_poke += 1 + if cached_work.state == PokeState.LANDED: + count_poke_success += 1 + elif cached_work.state == PokeState.POKE_EXCEPTION: + count_poke_exception += 1 + for cached_exception in self.cached_sensor_exceptions.values(): + if cached_exception.is_infra_failure and cached_exception.fail_current_run: + count_infra_failure += 1 + if cached_exception.fail_current_run: + count_exception_failures += 1 + + Stats.gauge("smart_sensor_operator.poked_tasks", count_poke) + Stats.gauge("smart_sensor_operator.poked_success", count_poke_success) + Stats.gauge("smart_sensor_operator.poked_exception", count_poke_exception) + Stats.gauge("smart_sensor_operator.exception_failures", count_exception_failures) + Stats.gauge("smart_sensor_operator.infra_failures", count_infra_failure) Review comment: Thanks for reminding. 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