airflow.models

Airflow models

Package Contents

airflow.models.ID_LEN = 250[source]
airflow.models.Base :Any[source]
class airflow.models.BaseOperator(task_id: str, owner: str = conf.get('operators', 'DEFAULT_OWNER'), email: Optional[Union[str, Iterable[str]]] = None, email_on_retry: bool = conf.getboolean('email', 'default_email_on_retry', fallback=True), email_on_failure: bool = conf.getboolean('email', 'default_email_on_failure', fallback=True), retries: Optional[int] = conf.getint('core', 'default_task_retries', fallback=0), retry_delay: timedelta = timedelta(seconds=300), retry_exponential_backoff: bool = False, max_retry_delay: Optional[timedelta] = None, start_date: Optional[datetime] = None, end_date: Optional[datetime] = None, depends_on_past: bool = False, wait_for_downstream: bool = False, dag=None, params: Optional[Dict] = None, default_args: Optional[Dict] = None, priority_weight: int = 1, weight_rule: str = conf.get('core', 'default_task_weight_rule', fallback=WeightRule.DOWNSTREAM), queue: str = conf.get('operators', 'default_queue'), pool: Optional[str] = None, pool_slots: int = 1, sla: Optional[timedelta] = None, execution_timeout: Optional[timedelta] = None, on_execute_callback: Optional[TaskStateChangeCallback] = None, on_failure_callback: Optional[TaskStateChangeCallback] = None, on_success_callback: Optional[TaskStateChangeCallback] = None, on_retry_callback: Optional[TaskStateChangeCallback] = None, pre_execute: Optional[TaskPreExecuteHook] = None, post_execute: Optional[TaskPostExecuteHook] = None, trigger_rule: str = TriggerRule.ALL_SUCCESS, resources: Optional[Dict] = None, run_as_user: Optional[str] = None, task_concurrency: Optional[int] = None, max_active_tis_per_dag: Optional[int] = None, executor_config: Optional[Dict] = None, do_xcom_push: bool = True, inlets: Optional[Any] = None, outlets: Optional[Any] = None, task_group: Optional['TaskGroup'] = None, doc: Optional[str] = None, doc_md: Optional[str] = None, doc_json: Optional[str] = None, doc_yaml: Optional[str] = None, doc_rst: Optional[str] = None, **kwargs)[source]

Bases: airflow.models.base.Operator, airflow.utils.log.logging_mixin.LoggingMixin, airflow.models.taskmixin.TaskMixin

Abstract base class for all operators. Since operators create objects that become nodes in the dag, BaseOperator contains many recursive methods for dag crawling behavior. To derive this class, you are expected to override the constructor as well as the 'execute' method.

Operators derived from this class should perform or trigger certain tasks synchronously (wait for completion). Example of operators could be an operator that runs a Pig job (PigOperator), a sensor operator that waits for a partition to land in Hive (HiveSensorOperator), or one that moves data from Hive to MySQL (Hive2MySqlOperator). Instances of these operators (tasks) target specific operations, running specific scripts, functions or data transfers.

This class is abstract and shouldn't be instantiated. Instantiating a class derived from this one results in the creation of a task object, which ultimately becomes a node in DAG objects. Task dependencies should be set by using the set_upstream and/or set_downstream methods.

Parameters
  • task_id (str) -- a unique, meaningful id for the task

  • owner (str) -- the owner of the task. Using a meaningful description (e.g. user/person/team/role name) to clarify ownership is recommended.

  • email (str or list[str]) -- the 'to' email address(es) used in email alerts. This can be a single email or multiple ones. Multiple addresses can be specified as a comma or semi-colon separated string or by passing a list of strings.

  • email_on_retry (bool) -- Indicates whether email alerts should be sent when a task is retried

  • email_on_failure (bool) -- Indicates whether email alerts should be sent when a task failed

  • retries (int) -- the number of retries that should be performed before failing the task

  • retry_delay (datetime.timedelta) -- delay between retries

  • retry_exponential_backoff (bool) -- allow progressive longer waits between retries by using exponential backoff algorithm on retry delay (delay will be converted into seconds)

  • max_retry_delay (datetime.timedelta) -- maximum delay interval between retries

  • start_date (datetime.datetime) -- The start_date for the task, determines the execution_date for the first task instance. The best practice is to have the start_date rounded to your DAG's schedule_interval. Daily jobs have their start_date some day at 00:00:00, hourly jobs have their start_date at 00:00 of a specific hour. Note that Airflow simply looks at the latest execution_date and adds the schedule_interval to determine the next execution_date. It is also very important to note that different tasks' dependencies need to line up in time. If task A depends on task B and their start_date are offset in a way that their execution_date don't line up, A's dependencies will never be met. If you are looking to delay a task, for example running a daily task at 2AM, look into the TimeSensor and TimeDeltaSensor. We advise against using dynamic start_date and recommend using fixed ones. Read the FAQ entry about start_date for more information.

  • end_date (datetime.datetime) -- if specified, the scheduler won't go beyond this date

  • depends_on_past (bool) -- when set to true, task instances will run sequentially and only if the previous instance has succeeded or has been skipped. The task instance for the start_date is allowed to run.

  • wait_for_downstream (bool) -- when set to true, an instance of task X will wait for tasks immediately downstream of the previous instance of task X to finish successfully or be skipped before it runs. This is useful if the different instances of a task X alter the same asset, and this asset is used by tasks downstream of task X. Note that depends_on_past is forced to True wherever wait_for_downstream is used. Also note that only tasks immediately downstream of the previous task instance are waited for; the statuses of any tasks further downstream are ignored.

  • dag (airflow.models.DAG) -- a reference to the dag the task is attached to (if any)

  • priority_weight (int) -- priority weight of this task against other task. This allows the executor to trigger higher priority tasks before others when things get backed up. Set priority_weight as a higher number for more important tasks.

  • weight_rule (str) -- weighting method used for the effective total priority weight of the task. Options are: { downstream | upstream | absolute } default is downstream When set to downstream the effective weight of the task is the aggregate sum of all downstream descendants. As a result, upstream tasks will have higher weight and will be scheduled more aggressively when using positive weight values. This is useful when you have multiple dag run instances and desire to have all upstream tasks to complete for all runs before each dag can continue processing downstream tasks. When set to upstream the effective weight is the aggregate sum of all upstream ancestors. This is the opposite where downstream tasks have higher weight and will be scheduled more aggressively when using positive weight values. This is useful when you have multiple dag run instances and prefer to have each dag complete before starting upstream tasks of other dags. When set to absolute, the effective weight is the exact priority_weight specified without additional weighting. You may want to do this when you know exactly what priority weight each task should have. Additionally, when set to absolute, there is bonus effect of significantly speeding up the task creation process as for very large DAGs. Options can be set as string or using the constants defined in the static class airflow.utils.WeightRule

  • queue (str) -- which queue to target when running this job. Not all executors implement queue management, the CeleryExecutor does support targeting specific queues.

  • pool (str) -- the slot pool this task should run in, slot pools are a way to limit concurrency for certain tasks

  • pool_slots (int) -- the number of pool slots this task should use (>= 1) Values less than 1 are not allowed.

  • sla (datetime.timedelta) -- time by which the job is expected to succeed. Note that this represents the timedelta after the period is closed. For example if you set an SLA of 1 hour, the scheduler would send an email soon after 1:00AM on the 2016-01-02 if the 2016-01-01 instance has not succeeded yet. The scheduler pays special attention for jobs with an SLA and sends alert emails for SLA misses. SLA misses are also recorded in the database for future reference. All tasks that share the same SLA time get bundled in a single email, sent soon after that time. SLA notification are sent once and only once for each task instance.

  • execution_timeout (datetime.timedelta) -- max time allowed for the execution of this task instance, if it goes beyond it will raise and fail.

  • on_failure_callback (TaskStateChangeCallback) -- a function to be called when a task instance of this task fails. a context dictionary is passed as a single parameter to this function. Context contains references to related objects to the task instance and is documented under the macros section of the API.

  • on_execute_callback (TaskStateChangeCallback) -- much like the on_failure_callback except that it is executed right before the task is executed.

  • on_retry_callback (TaskStateChangeCallback) -- much like the on_failure_callback except that it is executed when retries occur.

  • on_success_callback (TaskStateChangeCallback) -- much like the on_failure_callback except that it is executed when the task succeeds.

  • pre_execute (TaskPreExecuteHook) --

    a function to be called immediately before task execution, receiving a context dictionary; raising an exception will prevent the task from being executed.

    This is an experimental feature.

  • post_execute (TaskPostExecuteHook) --

    a function to be called immediately after task execution, receiving a context dictionary and task result; raising an exception will prevent the task from succeeding.

    This is an experimental feature.

  • trigger_rule (str) -- defines the rule by which dependencies are applied for the task to get triggered. Options are: { all_success | all_failed | all_done | one_success | one_failed | none_failed | none_failed_min_one_success | none_skipped | always} default is all_success. Options can be set as string or using the constants defined in the static class airflow.utils.TriggerRule

  • resources (dict) -- A map of resource parameter names (the argument names of the Resources constructor) to their values.

  • run_as_user (str) -- unix username to impersonate while running the task

  • max_active_tis_per_dag (int) -- When set, a task will be able to limit the concurrent runs across execution_dates.

  • executor_config (dict) --

    Additional task-level configuration parameters that are interpreted by a specific executor. Parameters are namespaced by the name of executor.

    Example: to run this task in a specific docker container through the KubernetesExecutor

    MyOperator(...,
        executor_config={
            "KubernetesExecutor":
                {"image": "myCustomDockerImage"}
        }
    )
    

  • do_xcom_push (bool) -- if True, an XCom is pushed containing the Operator's result

  • task_group (airflow.utils.task_group.TaskGroup) -- The TaskGroup to which the task should belong. This is typically provided when not using a TaskGroup as a context manager.

  • doc (str) -- Add documentation or notes to your Task objects that is visible in Task Instance details View in the Webserver

  • doc_md (str) -- Add documentation (in Markdown format) or notes to your Task objects that is visible in Task Instance details View in the Webserver

  • doc_rst (str) -- Add documentation (in RST format) or notes to your Task objects that is visible in Task Instance details View in the Webserver

  • doc_json (str) -- Add documentation (in JSON format) or notes to your Task objects that is visible in Task Instance details View in the Webserver

  • doc_yaml (str) -- Add documentation (in YAML format) or notes to your Task objects that is visible in Task Instance details View in the Webserver

template_fields :Iterable[str] = []
template_ext :Iterable[str] = []
template_fields_renderers :Dict[str, str]
ui_color :str = #fff
ui_fgcolor :str = #000
pool :str =
shallow_copy_attrs :Tuple[str, ...] = []
supports_lineage = False
dag

Returns the Operator's DAG if set, otherwise raises an error

dag_id

Returns dag id if it has one or an adhoc + owner

deps :Iterable[BaseTIDep]

Returns the set of dependencies for the operator. These differ from execution context dependencies in that they are specific to tasks and can be extended/overridden by subclasses.

priority_weight_total

Total priority weight for the task. It might include all upstream or downstream tasks. depending on the weight rule.

  • WeightRule.ABSOLUTE - only own weight

  • WeightRule.DOWNSTREAM - adds priority weight of all downstream tasks

  • WeightRule.UPSTREAM - adds priority weight of all upstream tasks

upstream_list

@property: list of tasks directly upstream

upstream_task_ids

@property: set of ids of tasks directly upstream

downstream_list

@property: list of tasks directly downstream

downstream_task_ids

@property: set of ids of tasks directly downstream

task_type

@property: type of the task

roots

Required by TaskMixin

leaves

Required by TaskMixin

output

Returns reference to XCom pushed by current operator

inherits_from_dummy_operator

Used to determine if an Operator is inherited from DummyOperator

__eq__(self, other)
__ne__(self, other)
__hash__(self)
__or__(self, other)

Called for [This Operator] | [Operator], The inlets of other will be set to pickup the outlets from this operator. Other will be set as a downstream task of this operator.

__gt__(self, other)

Called for [Operator] > [Outlet], so that if other is an attr annotated object it is set as an outlet of this Operator.

__lt__(self, other)

Called for [Inlet] > [Operator] or [Operator] < [Inlet], so that if other is an attr annotated object it is set as an inlet to this operator

__setattr__(self, key, value)
add_inlets(self, inlets: Iterable[Any])

Sets inlets to this operator

add_outlets(self, outlets: Iterable[Any])

Defines the outlets of this operator

get_inlet_defs(self)
Returns

list of inlets defined for this operator

get_outlet_defs(self)
Returns

list of outlets defined for this operator

has_dag(self)

Returns True if the Operator has been assigned to a DAG.

prepare_for_execution(self)

Lock task for execution to disable custom action in __setattr__ and returns a copy of the task

set_xcomargs_dependencies(self)

Resolves upstream dependencies of a task. In this way passing an XComArg as value for a template field will result in creating upstream relation between two tasks.

Example:

with DAG(...):
    generate_content = GenerateContentOperator(task_id="generate_content")
    send_email = EmailOperator(..., html_content=generate_content.output)

# This is equivalent to
with DAG(...):
    generate_content = GenerateContentOperator(task_id="generate_content")
    send_email = EmailOperator(
        ..., html_content="{{ task_instance.xcom_pull('generate_content') }}"
    )
    generate_content >> send_email

Returns dictionary of all extra links for the operator

Returns dictionary of all global extra links

pre_execute(self, context: Any)

This hook is triggered right before self.execute() is called.

execute(self, context: Any)

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.

post_execute(self, context: Any, result: Any = None)

This hook is triggered right after self.execute() is called. It is passed the execution context and any results returned by the operator.

on_kill(self)

Override this method to cleanup subprocesses when a task instance gets killed. Any use of the threading, subprocess or multiprocessing module within an operator needs to be cleaned up or it will leave ghost processes behind.

__deepcopy__(self, memo)

Hack sorting double chained task lists by task_id to avoid hitting max_depth on deepcopy operations.

__getstate__(self)
__setstate__(self, state)
render_template_fields(self, context: Dict, jinja_env: Optional[jinja2.Environment] = None)

Template all attributes listed in template_fields. Note this operation is irreversible.

Parameters
render_template(self, content: Any, context: Dict, jinja_env: Optional[jinja2.Environment] = None, seen_oids: Optional[Set] = None)

Render a templated string. The content can be a collection holding multiple templated strings and will be templated recursively.

Parameters
  • content (Any) -- Content to template. Only strings can be templated (may be inside collection).

  • context (dict) -- Dict with values to apply on templated content

  • jinja_env (jinja2.Environment) -- Jinja environment. Can be provided to avoid re-creating Jinja environments during recursion.

  • seen_oids (set) -- template fields already rendered (to avoid RecursionError on circular dependencies)

Returns

Templated content

get_template_env(self)

Fetch a Jinja template environment from the DAG or instantiate empty environment if no DAG.

prepare_template(self)

Hook that is triggered after the templated fields get replaced by their content. If you need your operator to alter the content of the file before the template is rendered, it should override this method to do so.

resolve_template_files(self)

Getting the content of files for template_field / template_ext

clear(self, start_date: Optional[datetime] = None, end_date: Optional[datetime] = None, upstream: bool = False, downstream: bool = False, session: Session = None)

Clears the state of task instances associated with the task, following the parameters specified.

get_task_instances(self, start_date: Optional[datetime] = None, end_date: Optional[datetime] = None, session: Session = None)

Get a set of task instance related to this task for a specific date range.

get_flat_relative_ids(self, upstream: bool = False, found_descendants: Optional[Set[str]] = None)

Get a flat set of relatives' ids, either upstream or downstream.

get_flat_relatives(self, upstream: bool = False)

Get a flat list of relatives, either upstream or downstream.

run(self, start_date: Optional[datetime] = None, end_date: Optional[datetime] = None, ignore_first_depends_on_past: bool = True, ignore_ti_state: bool = False, mark_success: bool = False, test_mode: bool = False, session: Session = None)

Run a set of task instances for a date range.

dry_run(self)

Performs dry run for the operator - just render template fields.

get_direct_relative_ids(self, upstream: bool = False)

Get set of the direct relative ids to the current task, upstream or downstream.

get_direct_relatives(self, upstream: bool = False)

Get list of the direct relatives to the current task, upstream or downstream.

__repr__(self)
add_only_new(self, item_set: Set[str], item: str, dag_id: str)

Adds only new items to item set

set_downstream(self, task_or_task_list: Union[TaskMixin, Sequence[TaskMixin]], edge_modifier: Optional[EdgeModifier] = None)

Set a task or a task list to be directly downstream from the current task. Required by TaskMixin.

set_upstream(self, task_or_task_list: Union[TaskMixin, Sequence[TaskMixin]], edge_modifier: Optional[EdgeModifier] = None)

Set a task or a task list to be directly upstream from the current task. Required by TaskMixin.

static xcom_push(context: Any, key: str, value: Any, execution_date: Optional[datetime] = None)

Make an XCom available for tasks to pull.

Parameters
  • context -- Execution Context Dictionary

  • key (str) -- A key for the XCom

  • value (any pickleable object) -- A value for the XCom. The value is pickled and stored in the database.

  • execution_date (datetime) -- if provided, the XCom will not be visible until this date. This can be used, for example, to send a message to a task on a future date without it being immediately visible.

Type

Any

static xcom_pull(context: Any, task_ids: Optional[List[str]] = None, dag_id: Optional[str] = None, key: str = XCOM_RETURN_KEY, include_prior_dates: Optional[bool] = None)

Pull XComs that optionally meet certain criteria.

The default value for key limits the search to XComs that were returned by other tasks (as opposed to those that were pushed manually). To remove this filter, pass key=None (or any desired value).

If a single task_id string is provided, the result is the value of the most recent matching XCom from that task_id. If multiple task_ids are provided, a tuple of matching values is returned. None is returned whenever no matches are found.

Parameters
  • context -- Execution Context Dictionary

  • key (str) -- A key for the XCom. If provided, only XComs with matching keys will be returned. The default key is 'return_value', also available as a constant XCOM_RETURN_KEY. This key is automatically given to XComs returned by tasks (as opposed to being pushed manually). To remove the filter, pass key=None.

  • task_ids (str or iterable of strings (representing task_ids)) -- Only XComs from tasks with matching ids will be pulled. Can pass None to remove the filter.

  • dag_id (str) -- If provided, only pulls XComs from this DAG. If None (default), the DAG of the calling task is used.

  • include_prior_dates (bool) -- If False, only XComs from the current execution_date are returned. If True, XComs from previous dates are returned as well.

Type

Any

@property: extra links for the task

For an operator, gets the URL that the external links specified in extra_links should point to.

Raises

ValueError -- The error message of a ValueError will be passed on through to the fronted to show up as a tooltip on the disabled link

Parameters
  • dttm -- The datetime parsed execution date for the URL being searched for

  • link_name -- The name of the link we're looking for the URL for. Should be one of the options specified in extra_links

Returns

A URL

classmethod get_serialized_fields(cls)

Stringified DAGs and operators contain exactly these fields.

is_smart_sensor_compatible(self)

Return if this operator can use smart service. Default False.

defer(self, *, trigger: BaseTrigger, method_name: str, kwargs: Optional[Dict[str, Any]] = None, timeout: Optional[timedelta] = None)

Marks this Operator as being "deferred" - that is, suspending its execution until the provided trigger fires an event.

This is achieved by raising a special exception (TaskDeferred) which is caught in the main _execute_task wrapper.

Abstract base class that defines how we get an operator link.

operators :ClassVar[List[Type[BaseOperator]]] = []

This property will be used by Airflow Plugins to find the Operators to which you want to assign this Operator Link

Returns

List of Operator classes used by task for which you want to create extra link

name

Name of the link. This will be the button name on the task UI.

Returns

link name

Link to external system.

Parameters
  • operator -- airflow operator

  • dttm -- datetime

Returns

link to external system

class airflow.models.Connection(conn_id: Optional[str] = None, conn_type: Optional[str] = None, description: Optional[str] = None, host: Optional[str] = None, login: Optional[str] = None, password: Optional[str] = None, schema: Optional[str] = None, port: Optional[int] = None, extra: Optional[Union[str, dict]] = None, uri: Optional[str] = None)[source]

Bases: airflow.models.base.Base, airflow.utils.log.logging_mixin.LoggingMixin

Placeholder to store information about different database instances connection information. The idea here is that scripts use references to database instances (conn_id) instead of hard coding hostname, logins and passwords when using operators or hooks.

See also

For more information on how to use this class, see: Managing Connections

Parameters
  • conn_id (str) -- The connection ID.

  • conn_type (str) -- The connection type.

  • description (str) -- The connection description.

  • host (str) -- The host.

  • login (str) -- The login.

  • password (str) -- The password.

  • schema (str) -- The schema.

  • port (int) -- The port number.

  • extra (str) -- Extra metadata. Non-standard data such as private/SSH keys can be saved here. JSON encoded object.

  • uri (str) -- URI address describing connection parameters.

EXTRA_KEY = __extra__
__tablename__ = connection
id
conn_id
conn_type
description
host
schema
login
port
is_encrypted
is_extra_encrypted
password

Password. The value is decrypted/encrypted when reading/setting the value.

extra

Extra data. The value is decrypted/encrypted when reading/setting the value.

extra_dejson

Returns the extra property by deserializing json.

on_db_load(self)
parse_from_uri(self, **uri)

This method is deprecated. Please use uri parameter in constructor.

get_uri(self)

Return connection in URI format

get_password(self)

Return encrypted password.

set_password(self, value: Optional[str])

Encrypt password and set in object attribute.

get_extra(self)

Return encrypted extra-data.

set_extra(self, value: str)

Encrypt extra-data and save in object attribute to object.

rotate_fernet_key(self)

Encrypts data with a new key. See: Fernet

get_hook(self)

Return hook based on conn_type.

__repr__(self)
log_info(self)

This method is deprecated. You can read each field individually or use the default representation (__repr__).

debug_info(self)

This method is deprecated. You can read each field individually or use the default representation (__repr__).

test_connection(self)

Calls out get_hook method and executes test_connection method on that.

classmethod get_connection_from_secrets(cls, conn_id: str)

Get connection by conn_id.

Parameters

conn_id -- connection id

Returns

connection

class airflow.models.DAG(dag_id: str, description: Optional[str] = None, schedule_interval: ScheduleIntervalArg = ScheduleIntervalArgNotSet, timetable: Optional[Timetable] = None, start_date: Optional[datetime] = None, end_date: Optional[datetime] = None, full_filepath: Optional[str] = None, template_searchpath: Optional[Union[str, Iterable[str]]] = None, template_undefined: Type[jinja2.StrictUndefined] = jinja2.StrictUndefined, user_defined_macros: Optional[Dict] = None, user_defined_filters: Optional[Dict] = None, default_args: Optional[Dict] = None, concurrency: Optional[int] = None, max_active_tasks: int = conf.getint('core', 'max_active_tasks_per_dag'), max_active_runs: int = conf.getint('core', 'max_active_runs_per_dag'), dagrun_timeout: Optional[timedelta] = None, sla_miss_callback: Optional[Callable[['DAG', str, str, List[str], List[TaskInstance]], None]] = None, default_view: str = conf.get('webserver', 'dag_default_view').lower(), orientation: str = conf.get('webserver', 'dag_orientation'), catchup: bool = conf.getboolean('scheduler', 'catchup_by_default'), on_success_callback: Optional[DagStateChangeCallback] = None, on_failure_callback: Optional[DagStateChangeCallback] = None, doc_md: Optional[str] = None, params: Optional[Dict] = None, access_control: Optional[Dict] = None, is_paused_upon_creation: Optional[bool] = None, jinja_environment_kwargs: Optional[Dict] = None, render_template_as_native_obj: bool = False, tags: Optional[List[str]] = None)[source]

Bases: airflow.utils.log.logging_mixin.LoggingMixin

A dag (directed acyclic graph) is a collection of tasks with directional dependencies. A dag also has a schedule, a start date and an end date (optional). For each schedule, (say daily or hourly), the DAG needs to run each individual tasks as their dependencies are met. Certain tasks have the property of depending on their own past, meaning that they can't run until their previous schedule (and upstream tasks) are completed.

DAGs essentially act as namespaces for tasks. A task_id can only be added once to a DAG.

Parameters
  • dag_id (str) -- The id of the DAG; must consist exclusively of alphanumeric characters, dashes, dots and underscores (all ASCII)

  • description (str) -- The description for the DAG to e.g. be shown on the webserver

  • schedule_interval (datetime.timedelta or dateutil.relativedelta.relativedelta or str that acts as a cron expression) -- Defines how often that DAG runs, this timedelta object gets added to your latest task instance's execution_date to figure out the next schedule

  • start_date (datetime.datetime) -- The timestamp from which the scheduler will attempt to backfill

  • end_date (datetime.datetime) -- A date beyond which your DAG won't run, leave to None for open ended scheduling

  • template_searchpath (str or list[str]) -- This list of folders (non relative) defines where jinja will look for your templates. Order matters. Note that jinja/airflow includes the path of your DAG file by default

  • template_undefined (jinja2.StrictUndefined) -- Template undefined type.

  • user_defined_macros (dict) -- a dictionary of macros that will be exposed in your jinja templates. For example, passing dict(foo='bar') to this argument allows you to {{ foo }} in all jinja templates related to this DAG. Note that you can pass any type of object here.

  • user_defined_filters (dict) -- a dictionary of filters that will be exposed in your jinja templates. For example, passing dict(hello=lambda name: 'Hello %s' % name) to this argument allows you to {{ 'world' | hello }} in all jinja templates related to this DAG.

  • default_args (dict) -- A dictionary of default parameters to be used as constructor keyword parameters when initialising operators. Note that operators have the same hook, and precede those defined here, meaning that if your dict contains 'depends_on_past': True here and 'depends_on_past': False in the operator's call default_args, the actual value will be False.

  • params (dict) -- a dictionary of DAG level parameters that are made accessible in templates, namespaced under params. These params can be overridden at the task level.

  • max_active_tasks (int) -- the number of task instances allowed to run concurrently

  • max_active_runs (int) -- maximum number of active DAG runs, beyond this number of DAG runs in a running state, the scheduler won't create new active DAG runs

  • dagrun_timeout (datetime.timedelta) -- specify how long a DagRun should be up before timing out / failing, so that new DagRuns can be created. The timeout is only enforced for scheduled DagRuns.

  • sla_miss_callback (callable) -- specify a function to call when reporting SLA timeouts. See sla_miss_callback for more information about the function signature and parameters that are passed to the callback.

  • default_view (str) -- Specify DAG default view (tree, graph, duration, gantt, landing_times), default tree

  • orientation (str) -- Specify DAG orientation in graph view (LR, TB, RL, BT), default LR

  • catchup (bool) -- Perform scheduler catchup (or only run latest)? Defaults to True

  • on_failure_callback (callable) -- A function to be called when a DagRun of this dag fails. A context dictionary is passed as a single parameter to this function.

  • on_success_callback (callable) -- Much like the on_failure_callback except that it is executed when the dag succeeds.

  • access_control (dict) -- Specify optional DAG-level actions, e.g., "{'role1': {'can_read'}, 'role2': {'can_read', 'can_edit'}}"

  • is_paused_upon_creation (bool or None) -- Specifies if the dag is paused when created for the first time. If the dag exists already, this flag will be ignored. If this optional parameter is not specified, the global config setting will be used.

  • jinja_environment_kwargs (dict) --

    additional configuration options to be passed to Jinja Environment for template rendering

    Example: to avoid Jinja from removing a trailing newline from template strings

    DAG(dag_id='my-dag',
        jinja_environment_kwargs={
            'keep_trailing_newline': True,
            # some other jinja2 Environment options here
        }
    )
    

    See: Jinja Environment documentation

  • render_template_as_native_obj (bool) -- If True, uses a Jinja NativeEnvironment to render templates as native Python types. If False, a Jinja Environment is used to render templates as string values.

  • tags (List[str]) -- List of tags to help filtering DAGs in the UI.

fileloc :str

File path that needs to be imported to load this DAG or subdag.

This may not be an actual file on disk in the case when this DAG is loaded from a ZIP file or other DAG distribution format.

dag_id
full_filepath
concurrency
max_active_tasks
access_control
description
default_view
pickle_id
tasks
task_ids
task_group
filepath
relative_fileloc

File location of the importable dag 'file' relative to the configured DAGs folder.

folder

Folder location of where the DAG object is instantiated.

owner

Return list of all owners found in DAG tasks.

Returns

Comma separated list of owners in DAG tasks

Return type

str

allow_future_exec_dates
concurrency_reached

This attribute is deprecated. Please use airflow.models.DAG.get_concurrency_reached method.

is_paused

This attribute is deprecated. Please use airflow.models.DAG.get_is_paused method.

normalized_schedule_interval
latest_execution_date

This attribute is deprecated. Please use airflow.models.DAG.get_latest_execution_date method.

subdags

Returns a list of the subdag objects associated to this DAG

roots

Return nodes with no parents. These are first to execute and are called roots or root nodes.

leaves

Return nodes with no children. These are last to execute and are called leaves or leaf nodes.

task
__repr__(self)
__eq__(self, other)
__ne__(self, other)
__lt__(self, other)
__hash__(self)
__enter__(self)
__exit__(self, _type, _value, _tb)
date_range(self, start_date: datetime, num: Optional[int] = None, end_date: Optional[datetime] = timezone.utcnow())
is_fixed_time_schedule(self)
following_schedule(self, dttm)

Calculates the following schedule for this dag in UTC.

Parameters

dttm -- utc datetime

Returns

utc datetime

previous_schedule(self, dttm)
get_next_data_interval(self, dag_model: 'DagModel')

Get the data interval of the next scheduled run.

For compatibility, this method infers the data interval from the DAG's schedule if the run does not have an explicit one set, which is possible for runs created prior to AIP-39.

This function is private to Airflow core and should not be depended as a part of the Python API.

get_run_data_interval(self, run: DagRun)

Get the data interval of this run.

For compatibility, this method infers the data interval from the DAG's schedule if the run does not have an explicit one set, which is possible for runs created prior to AIP-39.

This function is private to Airflow core and should not be depended as a part of the Python API.

infer_automated_data_interval(self, logical_date: datetime)

Infer a data interval for a run against this DAG.

This method is used to bridge runs created prior to AIP-39 implementation, which do not have an explicit data interval. Therefore, this method only considers schedule_interval values valid prior to Airflow 2.2.

DO NOT use this method is there is a known data interval.

next_dagrun_info(self, last_automated_dagrun: Union[None, datetime, DataInterval], *, restricted: bool = True)

Get information about the next DagRun of this dag after date_last_automated_dagrun.

This calculates what time interval the next DagRun should operate on (its execution date), and when it can be scheduled, , according to the dag's timetable, start_date, end_date, etc. This doesn't check max active run or any other "max_active_tasks" type limits, but only performs calculations based on the various date and interval fields of this dag and its tasks.

Parameters
  • date_last_automated_dagrun -- The max(execution_date) of existing "automated" DagRuns for this dag (scheduled or backfill, but not manual).

  • restricted -- If set to False (default is True), ignore start_date, end_date, and catchup specified on the DAG or tasks.

Returns

DagRunInfo of the next dagrun, or None if a dagrun is not going to be scheduled.

next_dagrun_after_date(self, date_last_automated_dagrun: Optional[pendulum.DateTime])
iter_dagrun_infos_between(self, earliest: Optional[pendulum.DateTime], latest: pendulum.DateTime, *, align: bool = True)

Yield DagRunInfo using this DAG's timetable between given interval.

DagRunInfo instances yielded if their logical_date is not earlier than earliest, nor later than latest. The instances are ordered by their logical_date from earliest to latest.

If align is False, the first run will happen immediately on earliest, even if it does not fall on the logical timetable schedule. The default is True, but subdags will ignore this value and always behave as if this is set to False for backward compatibility.

Example: A DAG is scheduled to run every midnight (0 0 * * *). If earliest is 2021-06-03 23:00:00, the first DagRunInfo would be 2021-06-03 23:00:00 if align=False, and 2021-06-04 00:00:00 if align=True.

get_run_dates(self, start_date, end_date=None)

Returns a list of dates between the interval received as parameter using this dag's schedule interval. Returned dates can be used for execution dates.

Parameters
  • start_date (datetime) -- The start date of the interval.

  • end_date (datetime) -- The end date of the interval. Defaults to timezone.utcnow().

Returns

A list of dates within the interval following the dag's schedule.

Return type

list

normalize_schedule(self, dttm)
get_last_dagrun(self, session=None, include_externally_triggered=False)
has_dag_runs(self, session=None, include_externally_triggered=True)
param(self, name: str, default=None)

Return a DagParam object for current dag.

Parameters
  • name -- dag parameter name.

  • default -- fallback value for dag parameter.

Returns

DagParam instance for specified name and current dag.

get_concurrency_reached(self, session=None)

Returns a boolean indicating whether the max_active_tasks limit for this DAG has been reached

get_is_active(self, session=None)

Returns a boolean indicating whether this DAG is active

get_is_paused(self, session=None)

Returns a boolean indicating whether this DAG is paused

handle_callback(self, dagrun, success=True, reason=None, session=None)

Triggers the appropriate callback depending on the value of success, namely the on_failure_callback or on_success_callback. This method gets the context of a single TaskInstance part of this DagRun and passes that to the callable along with a 'reason', primarily to differentiate DagRun failures.

Parameters
  • dagrun -- DagRun object

  • success -- Flag to specify if failure or success callback should be called

  • reason -- Completion reason

  • session -- Database session

get_active_runs(self)

Returns a list of dag run execution dates currently running

Returns

List of execution dates

get_num_active_runs(self, external_trigger=None, only_running=True, session=None)

Returns the number of active "running" dag runs

Parameters
  • external_trigger (bool) -- True for externally triggered active dag runs

  • session --

Returns

number greater than 0 for active dag runs

get_dagrun(self, execution_date: Optional[str] = None, run_id: Optional[str] = None, session: Optional[Session] = None)

Returns the dag run for a given execution date or run_id if it exists, otherwise none.

Parameters
  • execution_date -- The execution date of the DagRun to find.

  • run_id -- The run_id of the DagRun to find.

  • session --

Returns

The DagRun if found, otherwise None.

get_dagruns_between(self, start_date, end_date, session=None)

Returns the list of dag runs between start_date (inclusive) and end_date (inclusive).

Parameters
  • start_date -- The starting execution date of the DagRun to find.

  • end_date -- The ending execution date of the DagRun to find.

  • session --

Returns

The list of DagRuns found.

get_latest_execution_date(self, session: Session)

Returns the latest date for which at least one dag run exists

resolve_template_files(self)
get_template_env(self)

Build a Jinja2 environment.

set_dependency(self, upstream_task_id, downstream_task_id)

Simple utility method to set dependency between two tasks that already have been added to the DAG using add_task()

get_task_instances_before(self, base_date: datetime, num: int, *, session: Session)

Get num task instances before (including) base_date.

The returned list may contain exactly num task instances. It can have less if there are less than num scheduled DAG runs before base_date, or more if there are manual task runs between the requested period, which does not count toward num.

get_task_instances(self, start_date=None, end_date=None, state=None, session=None)
set_task_instance_state(self, task_id: str, execution_date: datetime, state: State, upstream: Optional[bool] = False, downstream: Optional[bool] = False, future: Optional[bool] = False, past: Optional[bool] = False, commit: Optional[bool] = True, session=None)

Set the state of a TaskInstance to the given state, and clear its downstream tasks that are in failed or upstream_failed state.

Parameters
  • task_id (str) -- Task ID of the TaskInstance

  • execution_date (datetime) -- execution_date of the TaskInstance

  • state (State) -- State to set the TaskInstance to

  • upstream (bool) -- Include all upstream tasks of the given task_id

  • downstream (bool) -- Include all downstream tasks of the given task_id

  • future (bool) -- Include all future TaskInstances of the given task_id

  • commit (bool) -- Commit changes

  • past (bool) -- Include all past TaskInstances of the given task_id

topological_sort(self, include_subdag_tasks: bool = False)

Sorts tasks in topographical order, such that a task comes after any of its upstream dependencies.

Heavily inspired by: http://blog.jupo.org/2012/04/06/topological-sorting-acyclic-directed-graphs/

Parameters

include_subdag_tasks -- whether to include tasks in subdags, default to False

Returns

list of tasks in topological order

set_dag_runs_state(self, state: str = State.RUNNING, session: Session = None, start_date: Optional[datetime] = None, end_date: Optional[datetime] = None, dag_ids: List[str] = None)
clear(self, task_ids=None, start_date=None, end_date=None, only_failed=False, only_running=False, confirm_prompt=False, include_subdags=True, include_parentdag=True, dag_run_state: DagRunState = DagRunState.QUEUED, dry_run=False, session=None, get_tis=False, recursion_depth=0, max_recursion_depth=None, dag_bag=None, exclude_task_ids: FrozenSet[str] = frozenset({}))

Clears a set of task instances associated with the current dag for a specified date range.

Parameters
  • task_ids (List[str]) -- List of task ids to clear

  • start_date (datetime.datetime or None) -- The minimum execution_date to clear

  • end_date (datetime.datetime or None) -- The maximum execution_date to clear

  • only_failed (bool) -- Only clear failed tasks

  • only_running (bool) -- Only clear running tasks.

  • confirm_prompt (bool) -- Ask for confirmation

  • include_subdags (bool) -- Clear tasks in subdags and clear external tasks indicated by ExternalTaskMarker

  • include_parentdag (bool) -- Clear tasks in the parent dag of the subdag.

  • dag_run_state -- state to set DagRun to. If set to False, dagrun state will not be changed.

  • dry_run (bool) -- Find the tasks to clear but don't clear them.

  • session (sqlalchemy.orm.session.Session) -- The sqlalchemy session to use

  • dag_bag (airflow.models.dagbag.DagBag) -- The DagBag used to find the dags subdags (Optional)

  • exclude_task_ids (frozenset) -- A set of task_id that should not be cleared

classmethod clear_dags(cls, dags, start_date=None, end_date=None, only_failed=False, only_running=False, confirm_prompt=False, include_subdags=True, include_parentdag=False, dag_run_state=DagRunState.QUEUED, dry_run=False)
__deepcopy__(self, memo)
sub_dag(self, *args, **kwargs)

This method is deprecated in favor of partial_subset

partial_subset(self, task_ids_or_regex: Union[str, RePatternType, Iterable[str]], include_downstream=False, include_upstream=True, include_direct_upstream=False)

Returns a subset of the current dag as a deep copy of the current dag based on a regex that should match one or many tasks, and includes upstream and downstream neighbours based on the flag passed.

Parameters
  • task_ids_or_regex ([str] or str or re.Pattern) -- Either a list of task_ids, or a regex to match against task ids (as a string, or compiled regex pattern).

  • include_downstream -- Include all downstream tasks of matched tasks, in addition to matched tasks.

  • include_upstream -- Include all upstream tasks of matched tasks, in addition to matched tasks.

has_task(self, task_id: str)
get_task(self, task_id: str, include_subdags: bool = False)
pickle_info(self)
pickle(self, session=None)
tree_view(self)

Print an ASCII tree representation of the DAG.

add_task(self, task)

Add a task to the DAG

Parameters

task (task) -- the task you want to add

add_tasks(self, tasks)

Add a list of tasks to the DAG

Parameters

tasks (list of tasks) -- a lit of tasks you want to add

run(self, start_date=None, end_date=None, mark_success=False, local=False, executor=None, donot_pickle=conf.getboolean('core', 'donot_pickle'), ignore_task_deps=False, ignore_first_depends_on_past=True, pool=None, delay_on_limit_secs=1.0, verbose=False, conf=None, rerun_failed_tasks=False, run_backwards=False, run_at_least_once=False)

Runs the DAG.

Parameters
  • start_date (datetime.datetime) -- the start date of the range to run

  • end_date (datetime.datetime) -- the end date of the range to run

  • mark_success (bool) -- True to mark jobs as succeeded without running them

  • local (bool) -- True to run the tasks using the LocalExecutor

  • executor (airflow.executor.base_executor.BaseExecutor) -- The executor instance to run the tasks

  • donot_pickle (bool) -- True to avoid pickling DAG object and send to workers

  • ignore_task_deps (bool) -- True to skip upstream tasks

  • ignore_first_depends_on_past (bool) -- True to ignore depends_on_past dependencies for the first set of tasks only

  • pool (str) -- Resource pool to use

  • delay_on_limit_secs (float) -- Time in seconds to wait before next attempt to run dag run when max_active_runs limit has been reached

  • verbose (bool) -- Make logging output more verbose

  • conf (dict) -- user defined dictionary passed from CLI

  • rerun_failed_tasks --

  • run_backwards --

  • run_at_least_once -- If true, always run the DAG at least once even if no logical run exists within the time range.

Type

bool

Type

bool

Type

bool

cli(self)

Exposes a CLI specific to this DAG

create_dagrun(self, state: DagRunState, execution_date: Optional[datetime] = None, run_id: Optional[str] = None, start_date: Optional[datetime] = None, external_trigger: Optional[bool] = False, conf: Optional[dict] = None, run_type: Optional[DagRunType] = None, session=None, dag_hash: Optional[str] = None, creating_job_id: Optional[int] = None, data_interval: Optional[Tuple[datetime, datetime]] = None)

Creates a dag run from this dag including the tasks associated with this dag. Returns the dag run.

Parameters
  • run_id (str) -- defines the run id for this dag run

  • run_type (airflow.utils.types.DagRunType) -- type of DagRun

  • execution_date (datetime.datetime) -- the execution date of this dag run

  • state (airflow.utils.state.DagRunState) -- the state of the dag run

  • start_date (datetime) -- the date this dag run should be evaluated

  • external_trigger (bool) -- whether this dag run is externally triggered

  • conf (dict) -- Dict containing configuration/parameters to pass to the DAG

  • creating_job_id (int) -- id of the job creating this DagRun

  • session (sqlalchemy.orm.session.Session) -- database session

  • dag_hash (str) -- Hash of Serialized DAG

  • data_interval (tuple[datetime, datetime] | None) -- Data interval of the DagRun

classmethod bulk_sync_to_db(cls, dags: Collection['DAG'], session=None)

This method is deprecated in favor of bulk_write_to_db

classmethod bulk_write_to_db(cls, dags: Collection['DAG'], session=None)

Ensure the DagModel rows for the given dags are up-to-date in the dag table in the DB, including calculated fields.

Note that this method can be called for both DAGs and SubDAGs. A SubDag is actually a SubDagOperator.

Parameters

dags (List[airflow.models.dag.DAG]) -- the DAG objects to save to the DB

Returns

None

sync_to_db(self, session=None)

Save attributes about this DAG to the DB. Note that this method can be called for both DAGs and SubDAGs. A SubDag is actually a SubDagOperator.

Returns

None

get_default_view(self)

This is only there for backward compatible jinja2 templates

static deactivate_unknown_dags(active_dag_ids, session=None)

Given a list of known DAGs, deactivate any other DAGs that are marked as active in the ORM

Parameters

active_dag_ids (list[unicode]) -- list of DAG IDs that are active

Returns

None

static deactivate_stale_dags(expiration_date, session=None)

Deactivate any DAGs that were last touched by the scheduler before the expiration date. These DAGs were likely deleted.

Parameters

expiration_date (datetime) -- set inactive DAGs that were touched before this time

Returns

None

static get_num_task_instances(dag_id, task_ids=None, states=None, session=None)

Returns the number of task instances in the given DAG.

Parameters
  • session -- ORM session

  • dag_id (unicode) -- ID of the DAG to get the task concurrency of

  • task_ids (list[unicode]) -- A list of valid task IDs for the given DAG

  • states (list[state]) -- A list of states to filter by if supplied

Returns

The number of running tasks

Return type

int

classmethod get_serialized_fields(cls)

Stringified DAGs and operators contain exactly these fields.

get_edge_info(self, upstream_task_id: str, downstream_task_id: str)

Returns edge information for the given pair of tasks if present, and None if there is no information.

set_edge_info(self, upstream_task_id: str, downstream_task_id: str, info: EdgeInfoType)

Sets the given edge information on the DAG. Note that this will overwrite, rather than merge with, existing info.

validate_schedule_and_params(self)

Validates & raise exception if there are any Params in the DAG which neither have a default value nor have the null in schema['type'] list, but the DAG have a schedule_interval which is not None.

class airflow.models.DagModel(concurrency=None, **kwargs)[source]

Bases: airflow.models.base.Base

Table containing DAG properties

__tablename__ = dag

These items are stored in the database for state related information

dag_id
root_dag_id
is_paused_at_creation
is_paused
is_subdag
is_active
last_parsed_time
last_pickled
last_expired
scheduler_lock
pickle_id
fileloc
owners
description
default_view
schedule_interval
tags
max_active_tasks
max_active_runs
has_task_concurrency_limits
next_dagrun
next_dagrun_data_interval_start
next_dagrun_data_interval_end
next_dagrun_create_after
__table_args__
parent_dag
NUM_DAGS_PER_DAGRUN_QUERY
next_dagrun_data_interval
timezone
safe_dag_id
relative_fileloc

File location of the importable dag 'file' relative to the configured DAGs folder.

__repr__(self)
static get_dagmodel(dag_id, session=None)
classmethod get_current(cls, dag_id, session=None)
get_last_dagrun(self, session=None, include_externally_triggered=False)
static get_paused_dag_ids(dag_ids: List[str], session: Session = None)

Given a list of dag_ids, get a set of Paused Dag Ids

Parameters
  • dag_ids -- List of Dag ids

  • session -- ORM Session

Returns

Paused Dag_ids

get_default_view(self)

Get the Default DAG View, returns the default config value if DagModel does not have a value

set_is_paused(self, is_paused: bool, including_subdags: bool = True, session=None)

Pause/Un-pause a DAG.

Parameters
  • is_paused -- Is the DAG paused

  • including_subdags -- whether to include the DAG's subdags

  • session -- session

classmethod deactivate_deleted_dags(cls, alive_dag_filelocs: List[str], session=None)

Set is_active=False on the DAGs for which the DAG files have been removed.

Parameters
  • alive_dag_filelocs -- file paths of alive DAGs

  • session -- ORM Session

classmethod dags_needing_dagruns(cls, session: Session)

Return (and lock) a list of Dag objects that are due to create a new DagRun.

This will return a resultset of rows that is row-level-locked with a "SELECT ... FOR UPDATE" query, you should ensure that any scheduling decisions are made in a single transaction -- as soon as the transaction is committed it will be unlocked.

calculate_dagrun_date_fields(self, dag: DAG, most_recent_dag_run: Union[None, datetime, DataInterval])

Calculate next_dagrun and next_dagrun_create_after`

Parameters
  • dag -- The DAG object

  • most_recent_dag_run -- DateTime of most recent run of this dag, or none if not yet scheduled.

class airflow.models.DagTag[source]

Bases: airflow.models.base.Base

A tag name per dag, to allow quick filtering in the DAG view.

__tablename__ = dag_tag
name
dag_id
__repr__(self)
class airflow.models.DagBag(dag_folder: Union[str, 'pathlib.Path', None] = None, include_examples: bool = conf.getboolean('core', 'LOAD_EXAMPLES'), include_smart_sensor: bool = conf.getboolean('smart_sensor', 'USE_SMART_SENSOR'), safe_mode: bool = conf.getboolean('core', 'DAG_DISCOVERY_SAFE_MODE'), read_dags_from_db: bool = False, store_serialized_dags: Optional[bool] = None, load_op_links: bool = True)[source]

Bases: airflow.utils.log.logging_mixin.LoggingMixin

A dagbag is a collection of dags, parsed out of a folder tree and has high level configuration settings, like what database to use as a backend and what executor to use to fire off tasks. This makes it easier to run distinct environments for say production and development, tests, or for different teams or security profiles. What would have been system level settings are now dagbag level so that one system can run multiple, independent settings sets.

Parameters
  • dag_folder (unicode) -- the folder to scan to find DAGs

  • include_examples (bool) -- whether to include the examples that ship with airflow or not

  • include_smart_sensor (bool) -- whether to include the smart sensor native DAGs that create the smart sensor operators for whole cluster

  • read_dags_from_db (bool) -- Read DAGs from DB if True is passed. If False DAGs are read from python files.

  • load_op_links (bool) -- Should the extra operator link be loaded via plugins when de-serializing the DAG? This flag is set to False in Scheduler so that Extra Operator links are not loaded to not run User code in Scheduler.

DAGBAG_IMPORT_TIMEOUT
SCHEDULER_ZOMBIE_TASK_THRESHOLD
store_serialized_dags

Whether or not to read dags from DB

dag_ids
Returns

a list of DAG IDs in this bag

Return type

List[unicode]

size(self)
Returns

the amount of dags contained in this dagbag

get_dag(self, dag_id, session: Session = None)

Gets the DAG out of the dictionary, and refreshes it if expired

Parameters

dag_id (str) -- DAG Id

process_file(self, filepath, only_if_updated=True, safe_mode=True)

Given a path to a python module or zip file, this method imports the module and look for dag objects within it.

bag_dag(self, dag, root_dag)

Adds the DAG into the bag, recurses into sub dags.

Raises

AirflowDagCycleException if a cycle is detected in this dag or its subdags.

Raises

AirflowDagDuplicatedIdException if this dag or its subdags already exists in the bag.

collect_dags(self, dag_folder: Union[str, 'pathlib.Path', None] = None, only_if_updated: bool = True, include_examples: bool = conf.getboolean('core', 'LOAD_EXAMPLES'), include_smart_sensor: bool = conf.getboolean('smart_sensor', 'USE_SMART_SENSOR'), safe_mode: bool = conf.getboolean('core', 'DAG_DISCOVERY_SAFE_MODE'))

Given a file path or a folder, this method looks for python modules, imports them and adds them to the dagbag collection.

Note that if a .airflowignore file is found while processing the directory, it will behave much like a .gitignore, ignoring files that match any of the regex patterns specified in the file.

Note: The patterns in .airflowignore are treated as un-anchored regexes, not shell-like glob patterns.

collect_dags_from_db(self)

Collects DAGs from database.

dagbag_report(self)

Prints a report around DagBag loading stats

sync_to_db(self, session: Optional[Session] = None)

Save attributes about list of DAG to the DB.

class airflow.models.DagPickle(dag)[source]

Bases: airflow.models.base.Base

Dags can originate from different places (user repos, main repo, ...) and also get executed in different places (different executors). This object represents a version of a DAG and becomes a source of truth for a BackfillJob execution. A pickle is a native python serialized object, and in this case gets stored in the database for the duration of the job.

The executors pick up the DagPickle id and read the dag definition from the database.

id
pickle
created_dttm
pickle_hash
__tablename__ = dag_pickle
class airflow.models.DagRun(dag_id: Optional[str] = None, run_id: Optional[str] = None, queued_at: Optional[datetime] = __NO_VALUE, execution_date: Optional[datetime] = None, start_date: Optional[datetime] = None, external_trigger: Optional[bool] = None, conf: Optional[Any] = None, state: Optional[DagRunState] = None, run_type: Optional[str] = None, dag_hash: Optional[str] = None, creating_job_id: Optional[int] = None, data_interval: Optional[Tuple[datetime, datetime]] = None)[source]

Bases: airflow.models.base.Base, airflow.utils.log.logging_mixin.LoggingMixin

DagRun describes an instance of a Dag. It can be created by the scheduler (for regular runs) or by an external trigger

__tablename__ = dag_run
id
dag_id
queued_at
execution_date
start_date
end_date
run_id
creating_job_id
external_trigger
run_type
conf
data_interval_start
data_interval_end
last_scheduling_decision
dag_hash
dag
__table_args__
task_instances
DEFAULT_DAGRUNS_TO_EXAMINE
logical_date
state
is_backfill
__repr__(self)
get_state(self)
set_state(self, state: DagRunState)
refresh_from_db(self, session: Session = None)

Reloads the current dagrun from the database

Parameters

session (Session) -- database session

classmethod active_runs_of_dags(cls, dag_ids=None, only_running=False, session=None)

Get the number of active dag runs for each dag.

classmethod next_dagruns_to_examine(cls, state: DagRunState, session: Session, max_number: Optional[int] = None)

Return the next DagRuns that the scheduler should attempt to schedule.

This will return zero or more DagRun rows that are row-level-locked with a "SELECT ... FOR UPDATE" query, you should ensure that any scheduling decisions are made in a single transaction -- as soon as the transaction is committed it will be unlocked.

Return type

list[airflow.models.DagRun]

static find(dag_id: Optional[Union[str, List[str]]] = None, run_id: Optional[str] = None, execution_date: Optional[datetime] = None, state: Optional[DagRunState] = None, external_trigger: Optional[bool] = None, no_backfills: bool = False, run_type: Optional[DagRunType] = None, session: Session = None, execution_start_date: Optional[datetime] = None, execution_end_date: Optional[datetime] = None)

Returns a set of dag runs for the given search criteria.

Parameters
  • dag_id (str or list[str]) -- the dag_id or list of dag_id to find dag runs for

  • run_id (str) -- defines the run id for this dag run

  • run_type (airflow.utils.types.DagRunType) -- type of DagRun

  • execution_date (datetime.datetime or list[datetime.datetime]) -- the execution date

  • state (DagRunState) -- the state of the dag run

  • external_trigger (bool) -- whether this dag run is externally triggered

  • no_backfills (bool) -- return no backfills (True), return all (False). Defaults to False

  • session (sqlalchemy.orm.session.Session) -- database session

  • execution_start_date (datetime.datetime) -- dag run that was executed from this date

  • execution_end_date (datetime.datetime) -- dag run that was executed until this date

static generate_run_id(run_type: DagRunType, execution_date: datetime)

Generate Run ID based on Run Type and Execution Date

get_task_instances(self, state: Optional[Iterable[TaskInstanceState]] = None, session=None)

Returns the task instances for this dag run

get_task_instance(self, task_id: str, session: Session = None)

Returns the task instance specified by task_id for this dag run

Parameters
  • task_id (str) -- the task id

  • session (Session) -- Sqlalchemy ORM Session

get_dag(self)

Returns the Dag associated with this DagRun.

Returns

DAG

get_previous_dagrun(self, state: Optional[DagRunState] = None, session: Session = None)

The previous DagRun, if there is one

get_previous_scheduled_dagrun(self, session: Session = None)

The previous, SCHEDULED DagRun, if there is one

update_state(self, session: Session = None, execute_callbacks: bool = True)

Determines the overall state of the DagRun based on the state of its TaskInstances.

Parameters
  • session (Session) -- Sqlalchemy ORM Session

  • execute_callbacks (bool) -- Should dag callbacks (success/failure, SLA etc) be invoked directly (default: true) or recorded as a pending request in the callback property

Returns

Tuple containing tis that can be scheduled in the current loop & callback that needs to be executed

task_instance_scheduling_decisions(self, session: Session = None)
verify_integrity(self, session: Session = None)

Verifies the DagRun by checking for removed tasks or tasks that are not in the database yet. It will set state to removed or add the task if required.

Parameters

session (Session) -- Sqlalchemy ORM Session

static get_run(session: Session, dag_id: str, execution_date: datetime)

Get a single DAG Run

Parameters
  • session (Session) -- Sqlalchemy ORM Session

  • dag_id (unicode) -- DAG ID

  • execution_date (datetime) -- execution date

Returns

DagRun corresponding to the given dag_id and execution date if one exists. None otherwise.

Return type

airflow.models.DagRun

classmethod get_latest_runs(cls, session=None)

Returns the latest DagRun for each DAG

schedule_tis(self, schedulable_tis: Iterable[TI], session: Session = None)

Set the given task instances in to the scheduled state.

Each element of schedulable_tis should have it's task attribute already set.

Any DummyOperator without callbacks is instead set straight to the success state.

All the TIs should belong to this DagRun, but this code is in the hot-path, this is not checked -- it is the caller's responsibility to call this function only with TIs from a single dag run.

class airflow.models.ImportError[source]

Bases: airflow.models.base.Base

A table to store all Import Errors. The ImportErrors are recorded when parsing DAGs. This errors are displayed on the Webserver.

__tablename__ = import_error
id
timestamp
filename
stacktrace
class airflow.models.Log(event, task_instance=None, owner=None, extra=None, **kwargs)[source]

Bases: airflow.models.base.Base

Used to actively log events to the database

__tablename__ = log
id
dttm
dag_id
task_id
event
execution_date
owner
extra
__table_args__
class airflow.models.Param(default: Any = __NO_VALUE_SENTINEL, description: str = None, **kwargs)[source]

Class to hold the default value of a Param and rule set to do the validations. Without the rule set it always validates and returns the default value.

Parameters
  • default (Any) -- The value this Param object holds

  • description (str) -- Optional help text for the Param

  • schema (dict) -- The validation schema of the Param, if not given then all kwargs except default & description will form the schema

has_value
resolve(self, value: Optional[Any] = __NO_VALUE_SENTINEL, suppress_exception: bool = False)

Runs the validations and returns the Param's final value. May raise ValueError on failed validations, or TypeError if no value is passed and no value already exists.

Parameters
  • value (Optional[Any]) -- The value to be updated for the Param

  • suppress_exception (bool) -- To raise an exception or not when the validations fails. If true and validations fails, the return value would be None.

dump(self)

Dump the Param as a dictionary

class airflow.models.Pool[source]

Bases: airflow.models.base.Base

the class to get Pool info.

__tablename__ = slot_pool
id
pool
slots
description
DEFAULT_POOL_NAME = default_pool
__repr__(self)
static get_pool(pool_name, session: Session = None)

Get the Pool with specific pool name from the Pools.

Parameters
  • pool_name -- The pool name of the Pool to get.

  • session -- SQLAlchemy ORM Session

Returns

the pool object

static get_default_pool(session: Session = None)

Get the Pool of the default_pool from the Pools.

Parameters

session -- SQLAlchemy ORM Session

Returns

the pool object

static slots_stats(*, lock_rows: bool = False, session: Session = None)

Get Pool stats (Number of Running, Queued, Open & Total tasks)

If lock_rows is True, and the database engine in use supports the NOWAIT syntax, then a non-blocking lock will be attempted -- if the lock is not available then SQLAlchemy will throw an OperationalError.

Parameters
  • lock_rows -- Should we attempt to obtain a row-level lock on all the Pool rows returns

  • session -- SQLAlchemy ORM Session

to_json(self)

Get the Pool in a json structure

Returns

the pool object in json format

occupied_slots(self, session: Session)

Get the number of slots used by running/queued tasks at the moment.

Parameters

session -- SQLAlchemy ORM Session

Returns

the used number of slots

running_slots(self, session: Session)

Get the number of slots used by running tasks at the moment.

Parameters

session -- SQLAlchemy ORM Session

Returns

the used number of slots

queued_slots(self, session: Session)

Get the number of slots used by queued tasks at the moment.

Parameters

session -- SQLAlchemy ORM Session

Returns

the used number of slots

open_slots(self, session: Session)

Get the number of slots open at the moment.

Parameters

session -- SQLAlchemy ORM Session

Returns

the number of slots

class airflow.models.RenderedTaskInstanceFields(ti: TaskInstance, render_templates=True)[source]

Bases: airflow.models.base.Base

Save Rendered Template Fields

__tablename__ = rendered_task_instance_fields
dag_id
task_id
execution_date
rendered_fields
k8s_pod_yaml
__repr__(self)
classmethod get_templated_fields(cls, ti: TaskInstance, session: Session = None)

Get templated field for a TaskInstance from the RenderedTaskInstanceFields table.

Parameters
  • ti -- Task Instance

  • session -- SqlAlchemy Session

Returns

Rendered Templated TI field

classmethod get_k8s_pod_yaml(cls, ti: TaskInstance, session: Session = None)

Get rendered Kubernetes Pod Yaml for a TaskInstance from the RenderedTaskInstanceFields table.

Parameters
  • ti -- Task Instance

  • session -- SqlAlchemy Session

Returns

Kubernetes Pod Yaml

write(self, session: Session = None)

Write instance to database

Parameters

session -- SqlAlchemy Session

classmethod delete_old_records(cls, task_id: str, dag_id: str, num_to_keep=conf.getint('core', 'max_num_rendered_ti_fields_per_task', fallback=0), session: Session = None)

Keep only Last X (num_to_keep) number of records for a task by deleting others

Parameters
  • task_id -- Task ID

  • dag_id -- Dag ID

  • num_to_keep -- Number of Records to keep

  • session -- SqlAlchemy Session

class airflow.models.SensorInstance(ti)[source]

Bases: airflow.models.base.Base

SensorInstance support the smart sensor service. It stores the sensor task states and context that required for poking include poke context and execution context. In sensor_instance table we also save the sensor operator classpath so that inside smart sensor there is no need to import the dagbag and create task object for each sensor task.

SensorInstance include another set of columns to support the smart sensor shard on large number of sensor instance. The key idea is to generate the hash code from the poke context and use it to map to a shorter shard code which can be used as an index. Every smart sensor process takes care of tasks whose shardcode are in a certain range.

__tablename__ = sensor_instance
id
task_id
dag_id
execution_date
state
start_date
operator
op_classpath
hashcode
shardcode
poke_context
execution_context
created_at
updated_at
__table_args__
try_number

Return the try number that this task number will be when it is actually run. If the TI is currently running, this will match the column in the database, in all other cases this will be incremented.

static get_classpath(obj)

Get the object dotted class path. Used for getting operator classpath.

Parameters

obj --

Returns

The class path of input object

Return type

str

classmethod register(cls, ti, poke_context, execution_context, session=None)

Register task instance ti for a sensor in sensor_instance table. Persist the context used for a sensor and set the sensor_instance table state to sensing.

Parameters
  • ti -- The task instance for the sensor to be registered.

  • poke_context (dict) -- Context used for sensor poke function.

  • execution_context (dict) -- Context used for execute sensor such as timeout setting and email configuration.

  • session (Session) -- SQLAlchemy ORM Session

Type

ti:

Returns

True if the ti was registered successfully.

Return type

Boolean

__repr__(self)
class airflow.models.SkipMixin[source]

Bases: airflow.utils.log.logging_mixin.LoggingMixin

A Mixin to skip Tasks Instances

skip(self, dag_run: 'DagRun', execution_date: 'timezone.DateTime', tasks: 'Iterable[BaseOperator]', session: 'Session' = None)

Sets tasks instances to skipped from the same dag run.

If this instance has a task_id attribute, store the list of skipped task IDs to XCom so that NotPreviouslySkippedDep knows these tasks should be skipped when they are cleared.

Parameters
  • dag_run -- the DagRun for which to set the tasks to skipped

  • execution_date -- execution_date

  • tasks -- tasks to skip (not task_ids)

  • session -- db session to use

skip_all_except(self, ti: TaskInstance, branch_task_ids: Union[str, Iterable[str]])

This method implements the logic for a branching operator; given a single task ID or list of task IDs to follow, this skips all other tasks immediately downstream of this operator.

branch_task_ids is stored to XCom so that NotPreviouslySkippedDep knows skipped tasks or newly added tasks should be skipped when they are cleared.

class airflow.models.SlaMiss[source]

Bases: airflow.models.base.Base

Model that stores a history of the SLA that have been missed. It is used to keep track of SLA failures over time and to avoid double triggering alert emails.

__tablename__ = sla_miss
task_id
dag_id
execution_date
email_sent
timestamp
description
notification_sent
__table_args__
__repr__(self)
class airflow.models.TaskFail(task, execution_date, start_date, end_date)[source]

Bases: airflow.models.base.Base

TaskFail tracks the failed run durations of each task instance.

__tablename__ = task_fail
id
task_id
dag_id
execution_date
start_date
end_date
duration
__table_args__
class airflow.models.TaskInstance(task, execution_date: Optional[datetime] = None, run_id: str = None, state: Optional[str] = None)[source]

Bases: airflow.models.base.Base, airflow.utils.log.logging_mixin.LoggingMixin

Task instances store the state of a task instance. This table is the authority and single source of truth around what tasks have run and the state they are in.

The SqlAlchemy model doesn't have a SqlAlchemy foreign key to the task or dag model deliberately to have more control over transactions.

Database transactions on this table should insure double triggers and any confusion around what task instances are or aren't ready to run even while multiple schedulers may be firing task instances.

__tablename__ = task_instance
task_id
dag_id
run_id
start_date
end_date
duration
state
max_tries
hostname
unixname
job_id
pool
pool_slots
queue
priority_weight
operator
queued_dttm
queued_by_job_id
pid
executor_config
external_executor_id
trigger_id
trigger_timeout
next_method
next_kwargs
__table_args__
dag_model
trigger
dag_run
execution_date
try_number

Return the try number that this task number will be when it is actually run.

If the TaskInstance is currently running, this will match the column in the database, in all other cases this will be incremented.

prev_attempted_tries

Based on this instance's try_number, this will calculate the number of previously attempted tries, defaulting to 0.

next_try_number

Setting Next Try Number

log_url

Log URL for TaskInstance

mark_success_url

URL to mark TI success

key

Returns a tuple that identifies the task instance uniquely

is_premature

Returns whether a task is in UP_FOR_RETRY state and its retry interval has elapsed.

previous_ti

This attribute is deprecated. Please use airflow.models.taskinstance.TaskInstance.get_previous_ti method.

previous_ti_success

This attribute is deprecated. Please use airflow.models.taskinstance.TaskInstance.get_previous_ti method.

previous_start_date_success

This attribute is deprecated. Please use airflow.models.taskinstance.TaskInstance.get_previous_start_date method.

init_on_load(self)

Initialize the attributes that aren't stored in the DB

command_as_list(self, mark_success=False, ignore_all_deps=False, ignore_task_deps=False, ignore_depends_on_past=False, ignore_ti_state=False, local=False, pickle_id=None, raw=False, job_id=None, pool=None, cfg_path=None)

Returns a command that can be executed anywhere where airflow is installed. This command is part of the message sent to executors by the orchestrator.

static generate_command(dag_id: str, task_id: str, run_id: str = None, mark_success: bool = False, ignore_all_deps: bool = False, ignore_depends_on_past: bool = False, ignore_task_deps: bool = False, ignore_ti_state: bool = False, local: bool = False, pickle_id: Optional[int] = None, file_path: Optional[str] = None, raw: bool = False, job_id: Optional[str] = None, pool: Optional[str] = None, cfg_path: Optional[str] = None)

Generates the shell command required to execute this task instance.

Parameters
  • dag_id (str) -- DAG ID

  • task_id (str) -- Task ID

  • run_id (datetime) -- The run_id of this task's DagRun

  • mark_success (bool) -- Whether to mark the task as successful

  • ignore_all_deps (bool) -- Ignore all ignorable dependencies. Overrides the other ignore_* parameters.

  • ignore_depends_on_past (bool) -- Ignore depends_on_past parameter of DAGs (e.g. for Backfills)

  • ignore_task_deps (bool) -- Ignore task-specific dependencies such as depends_on_past and trigger rule

  • ignore_ti_state (bool) -- Ignore the task instance's previous failure/success

  • local (bool) -- Whether to run the task locally

  • pickle_id (Optional[int]) -- If the DAG was serialized to the DB, the ID associated with the pickled DAG

  • file_path (Optional[str]) -- path to the file containing the DAG definition

  • raw (Optional[bool]) -- raw mode (needs more details)

  • job_id (Optional[int]) -- job ID (needs more details)

  • pool (Optional[str]) -- the Airflow pool that the task should run in

  • cfg_path (Optional[str]) -- the Path to the configuration file

Returns

shell command that can be used to run the task instance

Return type

list[str]

current_state(self, session=None)

Get the very latest state from the database, if a session is passed, we use and looking up the state becomes part of the session, otherwise a new session is used.

Parameters

session (Session) -- SQLAlchemy ORM Session

error(self, session=None)

Forces the task instance's state to FAILED in the database.

Parameters

session (Session) -- SQLAlchemy ORM Session

refresh_from_db(self, session=None, lock_for_update=False)

Refreshes the task instance from the database based on the primary key

Parameters
  • session (Session) -- SQLAlchemy ORM Session

  • lock_for_update (bool) -- if True, indicates that the database should lock the TaskInstance (issuing a FOR UPDATE clause) until the session is committed.

refresh_from_task(self, task, pool_override=None)

Copy common attributes from the given task.

Parameters
clear_xcom_data(self, session=None)

Clears all XCom data from the database for the task instance

Parameters

session (Session) -- SQLAlchemy ORM Session

set_state(self, state: str, session=None)

Set TaskInstance state.

Parameters
  • state (str) -- State to set for the TI

  • session (Session) -- SQLAlchemy ORM Session

are_dependents_done(self, session=None)

Checks whether the immediate dependents of this task instance have succeeded or have been skipped. This is meant to be used by wait_for_downstream.

This is useful when you do not want to start processing the next schedule of a task until the dependents are done. For instance, if the task DROPs and recreates a table.

Parameters

session (Session) -- SQLAlchemy ORM Session

get_previous_dagrun(self, state: Optional[str] = None, session: Optional[Session] = None)

The DagRun that ran before this task instance's DagRun.

Parameters
  • state -- If passed, it only take into account instances of a specific state.

  • session -- SQLAlchemy ORM Session.

get_previous_ti(self, state: Optional[str] = None, session: Session = None)

The task instance for the task that ran before this task instance.

Parameters
  • state -- If passed, it only take into account instances of a specific state.

  • session -- SQLAlchemy ORM Session

get_previous_execution_date(self, state: Optional[str] = None, session: Session = None)

The execution date from property previous_ti_success.

Parameters
  • state -- If passed, it only take into account instances of a specific state.

  • session -- SQLAlchemy ORM Session

get_previous_start_date(self, state: Optional[str] = None, session: Session = None)

The start date from property previous_ti_success.

Parameters
  • state -- If passed, it only take into account instances of a specific state.

  • session -- SQLAlchemy ORM Session

are_dependencies_met(self, dep_context=None, session=None, verbose=False)

Returns whether or not all the conditions are met for this task instance to be run given the context for the dependencies (e.g. a task instance being force run from the UI will ignore some dependencies).

Parameters
  • dep_context (DepContext) -- The execution context that determines the dependencies that should be evaluated.

  • session (sqlalchemy.orm.session.Session) -- database session

  • verbose (bool) -- whether log details on failed dependencies on info or debug log level

get_failed_dep_statuses(self, dep_context=None, session=None)

Get failed Dependencies

__repr__(self)
next_retry_datetime(self)

Get datetime of the next retry if the task instance fails. For exponential backoff, retry_delay is used as base and will be converted to seconds.

ready_for_retry(self)

Checks on whether the task instance is in the right state and timeframe to be retried.

get_dagrun(self, session: Session = None)

Returns the DagRun for this TaskInstance

Parameters

session -- SQLAlchemy ORM Session

Returns

DagRun

check_and_change_state_before_execution(self, verbose: bool = True, ignore_all_deps: bool = False, ignore_depends_on_past: bool = False, ignore_task_deps: bool = False, ignore_ti_state: bool = False, mark_success: bool = False, test_mode: bool = False, job_id: Optional[str] = None, pool: Optional[str] = None, external_executor_id: Optional[str] = None, session=None)

Checks dependencies and then sets state to RUNNING if they are met. Returns True if and only if state is set to RUNNING, which implies that task should be executed, in preparation for _run_raw_task

Parameters
  • verbose (bool) -- whether to turn on more verbose logging

  • ignore_all_deps (bool) -- Ignore all of the non-critical dependencies, just runs

  • ignore_depends_on_past (bool) -- Ignore depends_on_past DAG attribute

  • ignore_task_deps (bool) -- Don't check the dependencies of this TaskInstance's task

  • ignore_ti_state (bool) -- Disregards previous task instance state

  • mark_success (bool) -- Don't run the task, mark its state as success

  • test_mode (bool) -- Doesn't record success or failure in the DB

  • job_id (str) -- Job (BackfillJob / LocalTaskJob / SchedulerJob) ID

  • pool (str) -- specifies the pool to use to run the task instance

  • external_executor_id (str) -- The identifier of the celery executor

  • session (Session) -- SQLAlchemy ORM Session

Returns

whether the state was changed to running or not

Return type

bool

clear_next_method_args(self)
run(self, verbose: bool = True, ignore_all_deps: bool = False, ignore_depends_on_past: bool = False, ignore_task_deps: bool = False, ignore_ti_state: bool = False, mark_success: bool = False, test_mode: bool = False, job_id: Optional[str] = None, pool: Optional[str] = None, session=None)

Run TaskInstance

dry_run(self)

Only Renders Templates for the TI

handle_failure(self, error: Union[str, Exception], test_mode: Optional[bool] = None, force_fail: bool = False, error_file: Optional[str] = None, session=None)

Handle Failure for the TaskInstance

handle_failure_with_callback(self, error: Union[str, Exception], test_mode: Optional[bool] = None, force_fail: bool = False, session=None)
is_eligible_to_retry(self)

Is task instance is eligible for retry

get_template_context(self, session: Session = None, ignore_param_exceptions: bool = True)

Return TI Context

get_rendered_template_fields(self, session=None)

Fetch rendered template fields from DB

get_rendered_k8s_spec(self, session=None)

Fetch rendered template fields from DB

overwrite_params_with_dag_run_conf(self, params, dag_run)

Overwrite Task Params with DagRun.conf

render_templates(self, context: Optional[Context] = None)

Render templates in the operator fields.

render_k8s_pod_yaml(self)

Render k8s pod yaml

get_email_subject_content(self, exception)

Get the email subject content for exceptions.

email_alert(self, exception)

Send alert email with exception information.

set_duration(self)

Set TI duration

xcom_push(self, key: str, value: Any, execution_date: Optional[datetime] = None, session: Session = None)

Make an XCom available for tasks to pull.

Parameters
  • key (str) -- A key for the XCom

  • value (any picklable object) -- A value for the XCom. The value is pickled and stored in the database.

  • execution_date (datetime) -- if provided, the XCom will not be visible until this date. This can be used, for example, to send a message to a task on a future date without it being immediately visible.

  • session (Session) -- Sqlalchemy ORM Session

xcom_pull(self, task_ids: Optional[Union[str, Iterable[str]]] = None, dag_id: Optional[str] = None, key: str = XCOM_RETURN_KEY, include_prior_dates: bool = False, session: Session = None)

Pull XComs that optionally meet certain criteria.

The default value for key limits the search to XComs that were returned by other tasks (as opposed to those that were pushed manually). To remove this filter, pass key=None (or any desired value).

If a single task_id string is provided, the result is the value of the most recent matching XCom from that task_id. If multiple task_ids are provided, a tuple of matching values is returned. None is returned whenever no matches are found.

Parameters
  • key (str) -- A key for the XCom. If provided, only XComs with matching keys will be returned. The default key is 'return_value', also available as a constant XCOM_RETURN_KEY. This key is automatically given to XComs returned by tasks (as opposed to being pushed manually). To remove the filter, pass key=None.

  • task_ids (str or iterable of strings (representing task_ids)) -- Only XComs from tasks with matching ids will be pulled. Can pass None to remove the filter.

  • dag_id (str) -- If provided, only pulls XComs from this DAG. If None (default), the DAG of the calling task is used.

  • include_prior_dates (bool) -- If False, only XComs from the current execution_date are returned. If True, XComs from previous dates are returned as well.

  • session (Session) -- Sqlalchemy ORM Session

get_num_running_task_instances(self, session)

Return Number of running TIs from the DB

init_run_context(self, raw=False)

Sets the log context.

static filter_for_tis(tis: Iterable[Union['TaskInstance', TaskInstanceKey]])

Returns SQLAlchemy filter to query selected task instances

airflow.models.clear_task_instances(tis, session, activate_dag_runs=None, dag=None, dag_run_state: Union[DagRunState, Literal[False]] = DagRunState.QUEUED)[source]
Clears a set of task instances, but makes sure the running ones
get killed.
Parameters
  • tis -- a list of task instances

  • session -- current session

  • dag_run_state -- state to set DagRun to. If set to False, dagrun state will not be changed.

  • dag -- DAG object

  • activate_dag_runs -- Deprecated parameter, do not pass

class airflow.models.TaskReschedule(task, run_id, try_number, start_date, end_date, reschedule_date)[source]

Bases: airflow.models.base.Base

TaskReschedule tracks rescheduled task instances.

__tablename__ = task_reschedule
id
task_id
dag_id
run_id
try_number
start_date
end_date
duration
reschedule_date
__table_args__
dag_run
execution_date
static query_for_task_instance(task_instance, descending=False, session=None, try_number=None)

Returns query for task reschedules for a given the task instance.

Parameters
  • session (sqlalchemy.orm.session.Session) -- the database session object

  • task_instance (airflow.models.TaskInstance) -- the task instance to find task reschedules for

  • descending (bool) -- If True then records are returned in descending order

  • try_number (int) -- Look for TaskReschedule of the given try_number. Default is None which looks for the same try_number of the given task_instance.

static find_for_task_instance(task_instance, session=None, try_number=None)

Returns all task reschedules for the task instance and try number, in ascending order.

Parameters
  • session (sqlalchemy.orm.session.Session) -- the database session object

  • task_instance (airflow.models.TaskInstance) -- the task instance to find task reschedules for

  • try_number (int) -- Look for TaskReschedule of the given try_number. Default is None which looks for the same try_number of the given task_instance.

class airflow.models.Trigger(classpath: str, kwargs: Dict[str, Any], created_date: Optional[datetime.datetime] = None)[source]

Bases: airflow.models.base.Base

Triggers are a workload that run in an asynchronous event loop shared with other Triggers, and fire off events that will unpause deferred Tasks, start linked DAGs, etc.

They are persisted into the database and then re-hydrated into a "triggerer" process, where many are run at once. We model it so that there is a many-to-one relationship between Task and Trigger, for future deduplication logic to use.

Rows will be evicted from the database when the triggerer detects no active Tasks/DAGs using them. Events are not stored in the database; when an Event is fired, the triggerer will directly push its data to the appropriate Task/DAG.

__tablename__ = trigger
id
classpath
kwargs
created_date
triggerer_id
classmethod from_object(cls, trigger: BaseTrigger)

Alternative constructor that creates a trigger row based directly off of a Trigger object.

classmethod bulk_fetch(cls, ids: List[int], session=None)

Fetches all of the Triggers by ID and returns a dict mapping ID -> Trigger instance

classmethod clean_unused(cls, session=None)

Deletes all triggers that have no tasks/DAGs dependent on them (triggers have a one-to-many relationship to both)

classmethod submit_event(cls, trigger_id, event, session=None)

Takes an event from an instance of itself, and triggers all dependent tasks to resume.

classmethod submit_failure(cls, trigger_id, session=None)

Called when a trigger has failed unexpectedly, and we need to mark everything that depended on it as failed. Notably, we have to actually run the failure code from a worker as it may have linked callbacks, so hilariously we have to re-schedule the task instances to a worker just so they can then fail.

We use a special __fail__ value for next_method to achieve this that the runtime code understands as immediate-fail, and pack the error into next_kwargs.

TODO: Once we have shifted callback (and email) handling to run on workers as first-class concepts, we can run the failure code here in-process, but we can't do that right now.

classmethod ids_for_triggerer(cls, triggerer_id, session=None)

Retrieves a list of triggerer_ids.

classmethod assign_unassigned(cls, triggerer_id, capacity, session=None)

Takes a triggerer_id and the capacity for that triggerer and assigns unassigned triggers until that capacity is reached, or there are no more unassigned triggers.

class airflow.models.Variable(key=None, val=None, description=None)[source]

Bases: airflow.models.base.Base, airflow.utils.log.logging_mixin.LoggingMixin

Variables are a generic way to store and retrieve arbitrary content or settings as a simple key value store within Airflow.

__tablename__ = variable
id
key
description
is_encrypted
val

Get Airflow Variable from Metadata DB and decode it using the Fernet Key

on_db_load(self)
__repr__(self)
get_val(self)

Get Airflow Variable from Metadata DB and decode it using the Fernet Key

set_val(self, value)

Encode the specified value with Fernet Key and store it in Variables Table.

classmethod setdefault(cls, key, default, description=None, deserialize_json=False)

Like a Python builtin dict object, setdefault returns the current value for a key, and if it isn't there, stores the default value and returns it.

Parameters
  • key (str) -- Dict key for this Variable

  • default (Mixed) -- Default value to set and return if the variable isn't already in the DB

  • deserialize_json -- Store this as a JSON encoded value in the DB and un-encode it when retrieving a value

Returns

Mixed

classmethod get(cls, key: str, default_var: Any = __NO_DEFAULT_SENTINEL, deserialize_json: bool = False)

Gets a value for an Airflow Variable Key

Parameters
  • key -- Variable Key

  • default_var -- Default value of the Variable if the Variable doesn't exists

  • deserialize_json -- Deserialize the value to a Python dict

classmethod set(cls, key: str, value: Any, description: str = None, serialize_json: bool = False, session: Session = None)

Sets a value for an Airflow Variable with a given Key. This operation will overwrite an existing variable.

Parameters
  • key -- Variable Key

  • value -- Value to set for the Variable

  • description -- Value to set for the Variable

  • serialize_json -- Serialize the value to a JSON string

  • session -- SQL Alchemy Sessions

classmethod update(cls, key: str, value: Any, serialize_json: bool = False, session: Session = None)

Updates a given Airflow Variable with the Provided value

Parameters
  • key -- Variable Key

  • value -- Value to set for the Variable

  • serialize_json -- Serialize the value to a JSON string

  • session -- SQL Alchemy Session

classmethod delete(cls, key: str, session: Session = None)

Delete an Airflow Variable for a given key

Parameters
  • key -- Variable Key

  • session -- SQL Alchemy Sessions

rotate_fernet_key(self)

Rotate Fernet Key

check_for_write_conflict(key: str)

Logs a warning if a variable exists outside of the metastore.

If we try to write a variable to the metastore while the same key exists in an environment variable or custom secrets backend, then subsequent reads will not read the set value.

Parameters

key -- Variable Key

static get_variable_from_secrets(key: str)

Get Airflow Variable by iterating over all Secret Backends.

Parameters

key -- Variable Key

Returns

Variable Value

airflow.models.XCOM_RETURN_KEY = return_value[source]
airflow.models.XCom[source]

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