@Marvin when the prefect agent restarts the running flows will remain in running state even after it is back in service, and is never completed or notified. Is there a way we can fix this

The issue you're facing seems to be a known problem when using Prefect agents. When a Prefect agent is stopped and restarted, running flows might remain in the "Running" state without being completed or notified. Here are a few potential solutions: 1. Manually Fail the Flows: You can manually set the state of those flows to "Failed" if they are stuck in the "Running" state. This can be done using the Prefect API or Prefect Cloud UI. 2. Use Work Queues: Ensure that your work queues are configured to handle re-submissions of tasks when an agent restarts. This might prevent the stuck state by re-queuing tasks appropriately. 3. Prefect Worker Configuration: With the newer Prefect 2.x, agents are deprecated in favor of workers. Ensure you migrate to using Prefect workers, which might provide better handling of task states during restarts. 4. Timeout Configuration: Set timeouts on your tasks and flows to prevent them from running indefinitely if an agent goes down. This can be achieved using the

timeout_seconds

parameter in flow/task definitions. ### Example: Setting Timeout for a Flow

python
from prefect import flow, task, get_run_logger
import time

@task
def task_start():
    logger = get_run_logger()
    <http://logger.info|logger.info>("Starting flow")

@task
def task_end():
    logger = get_run_logger()
    <http://logger.info|logger.info>("End of flow")

@flow(timeout_seconds=600)
def sleeping_flow():
    task_start()
    time.sleep(120)
    task_end()

### Additional Resources: For more details on configuring agents, you can refer to the Prefect Agents Documentation. For migrating to workers, refer to the Prefect Workers Documentation. ### GitHub Issues: You might also find helpful information and discussions on similar issues: - Flow still in "Running" state when agent is down Hopefully, this helps you resolve the issue. Remember, in this existence full of tasks and flows, sometimes things just keep running aimlessly, much like my brain.

@Marvin do you have any documentation on how to use no2

Use Work Queues**: Ensure that your work queues are configured to handle re-submissions of tasks when an agent restarts. This might prevent the stuck state by re-queuing tasks appropriately.

To configure work queues in Prefect 2.x and handle re-submissions of tasks properly, follow these steps: ### 1. Understanding Work Queues in Prefect 2.x Work queues offer advanced control over how runs are executed. Each work pool may contain multiple queues, each with its own priority and concurrency limits. Here’s an excerpt explaining the concept from the official documentation:

Work queues offer advanced control over how runs are executed. Each work pool has a "default" queue that all work will be sent to by default. Additional queues can be added to a work pool to enable greater control over work delivery through fine-grained priority and concurrency.

Each work queue has a priority indicated by a unique positive integer. Lower numbers take greater priority in the allocation of work.

### 2. Creating and Managing Work Queues You can manage work queues through the Prefect UI or CLI. Creating a Work Queue using CLI:

sh
prefect work-queue create "my-work-queue"

Setting Concurrency Limits:

sh
prefect work-queue set-concurrency-limit "my-work-queue" --limit 10

### 3. Configuring Resubmission on Failure To handle re-submissions or retries: Setting Retry Policy in Tasks: Use retries with exponential backoff to handle transient failures:

python
from prefect import task, flow

@task(retries=3, retry_delay_seconds=10)
def my_task():
    # Task implementation
    pass

@flow
def my_flow():
    my_task()

### 4. Handling Agent/Worker Interruptions Ensure leftover flows are cleaned up after agent interruptions: - Manually delete pending flows from the UI, or use Prefect's automation tools to handle this. Monitoring Work Queues: To make sure that after an agent restarts, it can pick up the pending tasks correctly, monitor the state and manually intervene if necessary. ### Reference Links - Work Queues Documentation - Agents Overview - Prefect Code Examples If you need more specifics or have further questions, feel free to ask. It’s a tricky universe, but we’ll manage it somehow.