Module Contents



Key used to identify task instance.


Task instances store the state of a task instance. This table is the


Simplified Task Instance.



Sets the current execution context to the provided context object.


Load and return error from error file

set_error_file(error_file, error)

Write error into error file by path

clear_task_instances(tis, session, activate_dag_runs=None, dag=None, dag_run_state = DagRunState.QUEUED)

Clears a set of task instances, but makes sure the running ones







Sets the current execution context to the provided context object. This method should be called once per Task execution, before calling operator.execute.


Load and return error from error file

airflow.models.taskinstance.set_error_file(error_file, error)[source]

Write error into error file by path

airflow.models.taskinstance.clear_task_instances(tis, session, activate_dag_runs=None, dag=None, dag_run_state=DagRunState.QUEUED)[source]

Clears a set of task instances, but makes sure the running ones get killed.

  • tis – a list of task instances

  • session – current session

  • dag_run_state (Union[airflow.utils.state.DagRunState, airflow.typing_compat.Literal[False]]) – 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.taskinstance.TaskInstanceKey[source]

Bases: NamedTuple

Key used to identify task instance.

dag_id :str[source]
task_id :str[source]
run_id :str[source]
try_number :int = 1[source]
map_index :int[source]
property primary(self)[source]

Return task instance primary key part of the key

property reduced(self)[source]

Remake the key by subtracting 1 from try number to match in memory information

with_try_number(self, try_number)[source]

Returns TaskInstanceKey with provided try_number

property key(self)[source]

For API-compatibly with TaskInstance.

Returns self

class airflow.models.taskinstance.TaskInstance(task, execution_date=None, run_id=None, state=None, map_index=- 1)[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.

A value of -1 in map_index represents any of: a TI without mapped tasks; a TI with mapped tasks that has yet to be expanded (state=pending); a TI with mapped tasks that expanded to an empty list (state=skipped).

__tablename__ = task_instance[source]
task :airflow.models.operator.Operator[source]
static insert_mapping(run_id, task, map_index)[source]

Initialize the attributes that aren’t stored in the DB

property try_number(self)[source]

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.

property prev_attempted_tries(self)[source]

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

property next_try_number(self)[source]

Setting Next Try Number

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)[source]

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, task_id, run_id, mark_success=False, ignore_all_deps=False, ignore_depends_on_past=False, ignore_task_deps=False, ignore_ti_state=False, local=False, pickle_id=None, file_path=None, raw=False, job_id=None, pool=None, cfg_path=None, map_index=- 1)[source]

Generates the shell command required to execute this task instance.

  • dag_id (str) – DAG ID

  • task_id (str) – Task ID

  • run_id (str) – 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 (bool) – raw mode (needs more details)

  • job_id (Optional[str]) – 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


shell command that can be used to run the task instance

Return type


property log_url(self)[source]

Log URL for TaskInstance

property mark_success_url(self)[source]

URL to mark TI success

current_state(self, session=NEW_SESSION)[source]

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.


session – SQLAlchemy ORM Session

error(self, session=NEW_SESSION)[source]

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


session – SQLAlchemy ORM Session

refresh_from_db(self, session=NEW_SESSION, lock_for_update=False)[source]

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

  • session – SQLAlchemy ORM Session

  • lock_for_update – 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)[source]

Copy common attributes from the given task.

  • task (airflow.models.operator.Operator) – The task object to copy from

  • pool_override – Use the pool_override instead of task’s pool

clear_xcom_data(self, session=NEW_SESSION)[source]

Clear all XCom data from the database for the task instance.

If the task is unmapped, all XComs matching this task ID in the same DAG run are removed. If the task is mapped, only the one with matching map index is removed.


session (sqlalchemy.orm.session.Session) – SQLAlchemy ORM Session

property key(self)[source]

Returns a tuple that identifies the task instance uniquely

set_state(self, state, session=NEW_SESSION)[source]

Set TaskInstance state.

  • state (Optional[str]) – State to set for the TI

  • session – SQLAlchemy ORM Session

property is_premature(self)[source]

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

are_dependents_done(self, session=NEW_SESSION)[source]

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.


session – SQLAlchemy ORM Session

get_previous_dagrun(self, state=None, session=None)[source]

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

  • state (Optional[airflow.utils.state.DagRunState]) – If passed, it only take into account instances of a specific state.

  • session (Optional[sqlalchemy.orm.session.Session]) – SQLAlchemy ORM Session.

get_previous_ti(self, state=None, session=NEW_SESSION)[source]

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

  • state (Optional[airflow.utils.state.DagRunState]) – If passed, it only take into account instances of a specific state.

  • session (sqlalchemy.orm.session.Session) – SQLAlchemy ORM Session

property previous_ti(self)[source]

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

property previous_ti_success(self)[source]

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

get_previous_execution_date(self, state=None, session=NEW_SESSION)[source]

The execution date from property previous_ti_success.

  • state (Optional[airflow.utils.state.DagRunState]) – If passed, it only take into account instances of a specific state.

  • session (sqlalchemy.orm.session.Session) – SQLAlchemy ORM Session

get_previous_start_date(self, state=None, session=NEW_SESSION)[source]

The start date from property previous_ti_success.

  • state (Optional[airflow.utils.state.DagRunState]) – If passed, it only take into account instances of a specific state.

  • session (sqlalchemy.orm.session.Session) – SQLAlchemy ORM Session

property previous_start_date_success(self)[source]

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

are_dependencies_met(self, dep_context=None, session=NEW_SESSION, verbose=False)[source]

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).

  • dep_context – The execution context that determines the dependencies that should be evaluated.

  • session – database session

  • verbose – whether log details on failed dependencies on info or debug log level

get_failed_dep_statuses(self, dep_context=None, session=NEW_SESSION)[source]

Get failed Dependencies


Return repr(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.


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

get_dagrun(self, session=NEW_SESSION)[source]

Returns the DagRun for this TaskInstance


session (sqlalchemy.orm.session.Session) – SQLAlchemy ORM Session



Return type


check_and_change_state_before_execution(self, verbose=True, ignore_all_deps=False, ignore_depends_on_past=False, ignore_task_deps=False, ignore_ti_state=False, mark_success=False, test_mode=False, job_id=None, pool=None, external_executor_id=None, session=NEW_SESSION)[source]

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

  • 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 (Optional[str]) – Job (BackfillJob / LocalTaskJob / SchedulerJob) ID

  • pool (Optional[str]) – specifies the pool to use to run the task instance

  • external_executor_id (Optional[str]) – The identifier of the celery executor

  • session – SQLAlchemy ORM Session


whether the state was changed to running or not

Return type


run(self, verbose=True, ignore_all_deps=False, ignore_depends_on_past=False, ignore_task_deps=False, ignore_ti_state=False, mark_success=False, test_mode=False, job_id=None, pool=None, session=NEW_SESSION)[source]

Run TaskInstance


Only Renders Templates for the TI

static get_truncated_error_traceback(error, truncate_to)[source]

Truncates the traceback of an exception to the first frame called from within a given function

  • error (BaseException) – exception to get traceback from

  • truncate_to (Callable) – Function to truncate TB to. Must have a __code__ attribute

handle_failure(self, error=None, test_mode=None, force_fail=False, error_file=None, session=NEW_SESSION)[source]

Handle Failure for the TaskInstance

handle_failure_with_callback(self, error, test_mode=None, force_fail=False, session=NEW_SESSION)[source]

Is task instance is eligible for retry

get_template_context(self, session=NEW_SESSION, ignore_param_exceptions=True)[source]

Return TI Context

get_rendered_template_fields(self, session=NEW_SESSION)[source]

Update task with rendered template fields for presentation in UI. If task has already run, will fetch from DB; otherwise will render.

get_rendered_k8s_spec(self, session=NEW_SESSION)[source]

Fetch rendered template fields from DB

overwrite_params_with_dag_run_conf(self, params, dag_run)[source]

Overwrite Task Params with DagRun.conf

render_templates(self, context=None)[source]

Render templates in the operator fields.

If the task was originally mapped, this may replace self.task with the unmapped, fully rendered BaseOperator. The original self.task before replacement is returned.


Render k8s pod yaml

get_email_subject_content(self, exception, task=None)[source]

Get the email subject content for exceptions.

email_alert(self, exception, task)[source]

Send alert email with exception information.


Set TI duration

xcom_push(self, key, value, execution_date=None, session=NEW_SESSION)[source]

Make an XCom available for tasks to pull.

  • key (str) – Key to store the value under.

  • value (Any) – Value to store. What types are possible depends on whether enable_xcom_pickling is true or not. If so, this can be any picklable object; only be JSON-serializable may be used otherwise.

  • execution_date (Optional[datetime.datetime]) – Deprecated parameter that has no effect.

xcom_pull(self, task_ids=None, dag_id=None, key=XCOM_RETURN_KEY, include_prior_dates=False, session=NEW_SESSION, *, map_indexes=None, default=None)[source]

Pull XComs that optionally meet certain criteria.

  • 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 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 None.

  • task_ids (Optional[Union[str, Iterable[str]]]) – Only XComs from tasks with matching ids will be pulled. Pass None to remove the filter.

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

  • map_indexes (Optional[Union[int, Iterable[int]]]) – If provided, only pull XComs with matching indexes. If None (default), this is inferred from the task(s) being pulled (see below for details).

  • 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.

When pulling one single task (task_id is None or a str) without specifying map_indexes, the return value is inferred from whether the specified task is mapped. If not, value from the one single task instance is returned. If the task to pull is mapped, an iterator (not a list) yielding XComs from mapped task instances is returned. In either case, default (None if not specified) is returned if no matching XComs are found.

When pulling multiple tasks (i.e. either task_id or map_index is a non-str iterable), a list of matching XComs is returned. Elements in the list is ordered by item ordering in task_id and map_index.

get_num_running_task_instances(self, session)[source]

Return Number of running TIs from the DB

init_run_context(self, raw=False)[source]

Sets the log context.

static filter_for_tis(tis)[source]

Returns SQLAlchemy filter to query selected task instances

classmethod ti_selector_condition(cls, vals)[source]

Build an SQLAlchemy filter for a list where each element can contain whether a task_id, or a tuple of (task_id,map_index)

class airflow.models.taskinstance.SimpleTaskInstance(dag_id, task_id, run_id, start_date, end_date, try_number, map_index, state, executor_config, pool, queue, key, run_as_user=None, priority_weight=None)[source]

Simplified Task Instance.

Used to send data between processes via Queues.

__eq__(self, other)[source]

Return self==value.

classmethod from_ti(cls, ti)[source]
classmethod from_dict(cls, obj_dict)[source]

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