Airflow dag running but no tasks. 2, 2x schedulers, MySQL 8). I have max_active_runs = 1, but this still happens. e. from airflow. May 9, 2023 · is it normal in Airflow that if a DAG run fails, then the next scheduled DAG run gets stuck in the "running" state with all of its tasks in the "no status" state? This happens consistently for us, so presumably it is expected behaviour according to whichever arguments we have set that define that behaviour, but I don't know which arguments The method accepts one argument run_after, a pendulum. cfg (sql_alchemy_conn param) and then change your executor to LocalExecutor in airflow. There’s no guarantee that tasks will run at exactly the same time. core. have your run all the three components of airflow, namely: airflow webserver airflow scheduler airflow worker If you only run the previous two, the tasks will be queued, but not executed. DAG Runs. cfg and then run airflow initdb. The DAGs list may not update, and new tasks will not be scheduled. From my point of view the last run was on 2018-07-01 01:00 Because it ran today morning not yesterday. Mar 7, 2017 · airflow run dag_id task_id execution_date. Each DAG Run is run separately from one another, meaning that you can have many runs of a DAG at the same time. Apr 27, 2021 · We've been experiencing the same issues (Airflow 2. When the DAGs run, the tasks inside them don't get executed. Scheduler should never mark Dag complete if it has "Null" state tasks. What you expected to happen. Below are the steps I have done to fix it: Kill all airflow processes, using $ kill -9 <pid> Kill all celery processes, using $ pkill celery; Increses count for celery's worker_concurrency, parallelism, dag_concurrency configs in airflow. if you have set catchup=True. . A DAG (Directed Acyclic Graph) is the core concept of Airflow, collecting Tasks together, organized with dependencies and relationships to say how they should run. It will simply fail when it sees that not all dependent tasks are run. models import Reschedule def long_running_task(): if not task_complete: You can add the slack_alert task to your DAG and use Airflow's trigger_rule to execute it whenever a task Mar 12, 2018 · I want the tasks in the DAG to all finish before the 1st task of the next run gets executed. airflow. # run your first task instance airflow tasks test example_bash_operator runme_0 2015-01-01 # run a backfill over 2 days airflow dags backfill example_bash_operator \--start-date 2015-01-01 \--end-date 2015-01-02 May 2, 2017 · The intention is to kill certain running tasks once a particular task on airflow completes. airflow task_state [-h] [-sd SUBDIR] dag_id task_id execution_date Mar 21, 2019 · I have a DAG that has 30 (or more) dynamically created parallel tasks. dates. I did not expect anything to happen, but the previously stuck task instance started running! That was strange, but maybe DAG redeployment triggered it. I tried clicking on the "Running" circle in the "DAG Runs" column (the one to the right). Can anyone help me understand why? I've tried the following: changing the start date to past date; restarting web server and scheduler; Here is my code: Oct 10, 2018 · By default, Airflow uses SequentialExecutor which would execute task sequentially no matter what. 8 currently. today() and my schedule interval to "* * * * *". Did not find anything in any logs. " Apr 23, 2021 · Currently posted answers touch on different topic or does not seem to be fully correct. I added a task but it seems not updated when I check the log and UI (DAG->Code). I have concurrency option set on that DAG so that I only have single DAG Run running, when catching up the history. The dag is very simple with 2 independent tasks only dependent on last run. Zombie/Undead Tasks¶ No system runs perfectly, and task instances are expected to die once in a while. If you want to say “Task A must run before Task B”, you have to define the corresponding dependency. All tasks complete with success, but the DAG fails. This means that in your case dags a and b need to run on the same schedule (e. The code of the dag is the following: from airflow import DAG. When I inspect this DAG Run in the UI, I see the following: Jun 13, 2021 · When there is a task running, Airflow will pop a notice saying the scheduler does not appear to be running and it kept showing until the task finished: The scheduler does not appear to be running. Jul 1, 2018 · According to the "Latest Run" of the first task with is 2018-06-30 01:00 I suspect that I don't actually understand Airflow clock. operators. There are also tasks in the same dag that are stuck with no status (white icon). But it didn't stop running. state have your run all the three components of airflow, namely: airflow webserver airflow scheduler airflow worker If you only run the previous two, the tasks will be queued, but not executed. Jan 10, 2012 · Both Task Instances will have execution_date equal to the DAG Run’s execution_date, and each task_2 will be downstream of (depends on) its task_1. get_task_instances(): if task_instance. When I run the function myself, it works fine. Multiple DAG runs may be running at once for a particular DAG, each of them having a different execution_date. This is most commonly seen when the start_date is set to some dynamic value e. Oct 30, 2018 · I have experienced the same. I've found myself in a situation where I manually trigger a DAG Run (via airflow trigger_dag datablocks_dag) run, and the Dag Run shows up in the interface, but it then stays "Running" forever without actually doing anything. For example: task1 >> task2 Which would run task1 first, wait for it to complete, and only then run task2. May 30, 2019 · Options that are specified across an entire Airflow setup:. Aug 29, 2019 · 7. python_operator import PythonOperator. airflow run --force=true dag_1 task_1 2017-1-23 The airflow backfill command will run any executions that would have run in the time period specified from the start to end date. May 4, 2018 · I'm trying out airflow with the BigQueryOperator. Now select the first task and click on Task Instance. Dag still have an old version of my dag file. Apr 15, 2019 · For references of the images below, the ID of the DAG is xcom_4_modules_ver_5. Last heartbeat was received 5 minutes ago. Jul 26, 2018 · It is usually very easy to find out about the reason why a task is not being run. 2 is not compatible with airflow 1. Airflow executes tasks of a DAG on different servers in case you are using Kubernetes executor or Celery executor. This creates the opportunity for the execution date of a delayed dag execution to be before what the dag now thinks is Jan 10, 2010 · A DAG run is a physical instance of a DAG, containing task instances that run for a specific execution_date. When the DAG is unpaused, any “scheduled” tasks will begin running according to the DAG logic. Or that the DAG Run for 2016-01-01 is the previous DAG Run to the Apr 28, 2017 · I would like to create a conditional task in Airflow as described in the schema below. Therefore, you should not store any file or config in the local filesystem as the next task is likely to run on a different server without access to it — for example, a task that downloads the data file that the next task processes. Apr 28, 2017 · I would like to create a conditional task in Airflow as described in the schema below. parallelism: maximum number of tasks running across an entire Airflow installation; core. How? task_a >> task_b # Or task_b << task_a May 2, 2021 · Clearing the state of the DAG Run doesn’t help, it only shows “No task instances to clear” Root Cause / Solution The root cause turned out to be that the DAG’s start_date is later than the execution_date of the backfill DAG Run. models import TaskInstance from airflow. I was sure that it is going to get stuck again after processing the currently running task, but it did not happen! The Jul 5, 2019 · I have scheduled my airflow DAGs to run, every DAG has one task inside of them. Nov 17, 2021 · In Airflow, you can define order between tasks using >>. Sep 29, 2023 · Define tasks: Add tasks to your DAG, specifying the task type (e. task_id != kwargs['task_instance']. Logs for the example DAGs show up fine. cfg file. Sep 1, 2021 · No response. A DAG Run is an object representing an instantiation of the DAG in time. What happened. 35 Airflow tasks get stuck at "queued" status and never Dynamic DAGs with external configuration from a structured data file¶. Mar 5, 2020 · Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question. The workflow and its underlying tasks do appear. Nov 21, 2016 · If you think you have 1, 2, 3 steps all correct but the DAG is not running. python_operator import PythonOperator from datetime Apr 26, 2017 · In the DAGs screen you can see the running tasks: Example. Any time the DAG is executed, a DAG Run is created and all tasks inside it are executed. Jul 3, 2017 · airflow run tutorial python_operator2 2015-06-01 --ignore_dependencies=False If you want to execute the entire dag and execute both tasks, use trigger_dag: airflow trigger_dag tutorial For reference, airflow test will "run a task without checking for dependencies. So to allow Airflow to run tasks in Parallel you will need to create a database in Postges or MySQL and configure it in airflow. I have set my start date to datetime. I have airflow up and running an BashOperator works fine, I can also run airflow test <dag> <task> where task is the big query task I want to run, but when I trigger the DAG from the UI the bigquery task is never queued. Here's my code for the same (I am trying to SSH into an Apr 26, 2019 · I am using Airflow 1. This also allows passing a list: Sep 22, 2023 · A DAG has directed edges. Oct 25, 2018 · * Fix Sequential Executor without start scheduler Fix puckel/docker-airflow#254 In readme run `docker run -d -p 8080:8080 puckel/docker-airflow webserver` will not start scheduler this PR fix it * Allow SQL Alchemy environment variable Currently entrypoint. The expected scenario is the following: Task 1 executes If Task 1 succeed, then execute Task 2a Else If Task 1 Communication¶. 2 Tasks added to DAG during runtime fail to be scheduled. models import DAG from airflow. Running a dag that is manually triggered, and has only 1 step, sometimes the scheduler marks the DAG as success without running the step at all. After running the DAG through a scheduled process and triggering manually through the UI, I executed airflow list_dag_runs xcom_4_modules_ver_5 on CLI to check the status of DAG run. utils. utcnow(), which is always >= the dag_run start_date, in this case Airflow will mark the run as succeeded without running it. current_state() != State. The dag is as follows: from airflow. The DAG was successfully executed and wrote the expected output in log file. For this variable, it's better to choose the minimum date of your runs, if you don't have one, you can use the yesterday date, but the next day you will not be able to re-run the tasks failed on the previous day: Jul 30, 2019 · If you want to get the list of tasks inside of a DAG, you could use: from airflow import settings from airflow. the prior day is Saturday or Sunday), it should be Sep 6, 2022 · The problem is with 'start_date': datetime. 6 days ago · Sometimes a DAG run does not end because Airflow tasks get stuck and DAG run lasts longer than expected. Solution: In Airflow, parallelism depends on what resources are available to the airflow worker / airflow scheduler AND what your environment configuration is. , PythonOperator, BashOperator), and providing details such as the Python callable to execute or the bash command to run. Also btw, celery 4. May 2, 2022 · I am trying to run a simple DAG on Airflow running on Docker. I've got two python scripts, the first one takes in the data using an API call, and the second one pushes the data into google sheets. Sep 13, 2017 · Whenever I try to run a DAG, it will be in the running state but the tasks will not run. Commonly, Airflow determines which DagRun to run next by looking up the latest DagRun. Feb 28, 2018 · Metrics on scheduler do not show heavy load. Jun 1, 2020 · I added the dag to all of the tasks and redeployed the DAG configuration. The status of the DAG Run depends on the tasks states. 0. When in the Airflow web UI: select any DAG of interest; now click on the task; again, click on Task Instance Details; In the first row there is a panel Task Instance State; In the box Reason next to it is the reason why a task is being run - or why a task is being Aug 19, 2021 · If you see dag runs that are marked as success but don’t have any task runs, this means the dag runs’ execution_date was earlier than the dag’s start_date. I thought I would use google composer later on, but I want it running locally first. days_ago(0). The expected scenario is the following: Task 1 executes If Task 1 succeed, then execute Task 2a Else If Task 1 Jul 13, 2017 · I'm having trouble updating a dag file. Since our timetable creates a data interval for each complete work day, the data interval inferred here should usually start at the midnight one day prior to run_after, but if run_after falls on a Sunday or Monday (i. So the db clean command will preserve the latest non-manually-triggered DAG run to preserve continuity in scheduling. Here’s a basic example DAG: It defines four Tasks - A, B, C, and D - and dictates the order in which they have to run, and which tasks depend on what others. Airflow shows that the DAG was successfully triggered, but nothing gets uploaded to my computer. dag_concurrency: max number of tasks that can be running per DAG (across multiple DAG runs) Jan 7, 2024 · The workflow appears in the Airflow UI, but no logs exist, either under graph/tasks/log or in ~/airflow/logs folder. dates import days_ago from airflow. DAGs with no “scheduled” tasks will begin running according to their schedule. Asking for help, clarification, or responding to other answers. Manually triggering a run will start the dag but the task will not run due to: Jan 23, 2017 · If you run it once with the . It was running completely fine everyday, until yesterday where I manually triggered the dag a few hours after the scheduled run. 8. We can also say that task_1 for 2016-01-01 is the previous task instance of the task_1 for 2016-01-02. I then manually created a dag_id=<dag_name> folder under logs, but still nothing. I of course checked the dag directory path in airflow. Or the DAG can run every xx minutes, but failed to trigger even once in a daily interval, try create a new python file, copy your DAG code there, rename it so that the file is unique and then test again. It let me select the process and mark it as "failed". SUCCESS and \ task_instance. On 'Recent Tasks' press the running icon and Airflow will automatically run the search query with the filters for the Dag Id and State equal to 'running' and show the results on the Task Instances screen (you can find it manually on the tab Browse > Task Instances). I have very simple tasks. For example, we might Jul 11, 2017 · Airflow DAG run fails when task is up for retry. Furthermore, when a task has depends_on_past=True this will cause the DAG to completely lock as no future runs can be created. If you delete all DAG runs, Airflow may schedule an old DAG run that was already completed, e. sh is overwriting AIRFLOW__CORE__SQL_ALCHEMY_CONN Implement mechanism to allow it to have default set only if not specified. Under normal conditions, Airflow tasks do not stay indefinitely in the queued or running state, because Airflow has timeout and cleanup procedures that help avoid this situation. I tried clicking on the "Running" circle in the "Recent Tasks" column (the one to the left). dummy_operator import DummyOperator from airflow. cfg and restarted airflow webserver/scheduler. 1. How can I run a specific task and all its dependencies? I am guessing this is not possible because of an airflow design decision, but is there a way to get around this? Airflow is a platform that lets you build and run workflows. Sep 2, 2020 · I have a airflow job with a daily schedule. task_id: raise Exception("Task {} failed. Fix: Use the dagrun_timeout parameter for the DAGs. Aug 7, 2018 · To expand on Bas Harenslak answer, a simpler _finally function which will check the state of all tasks (not only the upstream ones) can be: def _finally(**kwargs): for task_instance in kwargs['dag_run']. In the paragraph Task Instance Details you will see why a DAG is waiting or not running. A DAG run is usually created by the Airflow scheduler, but can also be created by an external trigger. Apr 5, 2021 · I have a very simple dag which is supposed to run every Monday at 19:10. However, the task is not executed and hence the DAG makes nothing. This Jul 11, 2019 · I have a dummy DAG that I want to start episodically by setting its start_date to today and letting its schedul interval to daily. I look at the Apr 1, 2022 · If nothing else works, you can use the web ui to click on the dag, then on Graph View. A workflow is represented as a DAG (a Directed Acyclic Graph), and contains individual pieces of work called Tasks, arranged with dependencies and data flows taken into account. g. A DAG specifies the dependencies between tasks, which defines the order in which to execute the tasks. I have a DAG in airflow with one task (a python operator) which I force to run in the GUI and it gets the successful state. Feb 2, 2024 · from airflow. Airflow detects two kinds of task/process mismatch: Zombie tasks are TaskInstances stuck in a running state despite their associated jobs being inactive (e. When a DAG is paused, any running tasks are allowed to complete and all downstream tasks are put in to a state of “Scheduled”. default_args = { 'depends_on_past': True, ' Oct 18, 2017 · ExternalTaskSensor assumes that you are dependent on a task in a dag run with the same execution date. 7 or 1. Provide details and share your research! But avoid …. Aug 15, 2018 · I could not find any way to stop the DAG. Interesting thing to notice is when I restart the scheduler tasks change to running state. The step status remains Null in the db and in UI. The day after that (today) the task did not get executed). The DAG status is successful, but tasks are not running. would run all upstream tasks, but it does not. DateTime object that indicates when the DAG is externally triggered. their process did not send a recent heartbeat as it got killed, or the machine died Aug 24, 2017 · In my case, all Airflow tasks got stuck and none of them were running. Apr 19, 2017 · To run any DAGs, you need to make sure two processes are running: airflow webserver; airflow scheduler; If you only have airflow webserver running, the UI will show DAGs as running, but if you click on the DAG, none of it's tasks are actually running or scheduled, but rather in a Null state. here is the DAG code: #!/usr/bin/env python # -*- coding: utf-8 -*- # -*- airflow: DAG -*- import logging from airflow import DAG from airflow. 10. Jul 11, 2021 · I'm trying to run a simple ETL DAG with Airflow. Adding trigger rule all_failed to Task-C won't work for OP's example DAG: A >> B >> C unless Task-A ends in failed state, which most probably is not desirable. I have no issue running it (but with the old dag file). airflow run dag_1 task_1 2017-1-23 The run is saved and running it again won't do anything you can try to re-run it by forcing it. In my case, it was the DAG's dagrun_timeout setting that was set too low for my tasks that did run for more than 30 minutes: dag = DAG(, dagrun_timeout=timedelta(minutes=30), ) I am on Airflow version 1. airflow worker will provide the workers that actually execute the dags. Those directed edges correspond to the dependencies between tasks (operators) in an Airflow DAG. Here is the output of what this paragraph is showing me: What is the best way to find the reason, why the tasks won Mar 17, 2020 · I am trying to run a sample Airflow DAG. I have a DAG that I believe I have scheduled to run every 5 minutes, but it isn't doing so: Ignore the 2 successful DAG runs, those were manually triggered. If you need to use a more complex meta-data to prepare your DAG structure and you would prefer to keep the data in a structured non-python format, you should export the data to the DAG folder in a file and push it to the DAG folder, rather than try to pull the data by the DAG’s top-level code - for the reasons explained Jul 25, 2024 · (max_active_tasks_per_dag, max_active_tasks, max_active_tis_per_dag) Scenario: Tasks aren’t running at the same time. every day at 9:00am or w/e). DAGs. zinjuhdgltlxigrpynlnjbrfkolmccyuaqzzkqhlqeymroryznltk
