@Marvin, my flows are getting stuck at pending state, can I somehow manually create the state from db so that it can be picked up by workers ?

It seems you're not alone in experiencing issues with flows getting stuck in a pending state in Prefect. There are several GitHub issues and documentation references that might shed light on this: 1. GitHub Issues: - Prefect job stuck in Pending state: This issue discusses intermittent problems with flows getting stuck in a pending state, often related to network or server issues. - Flow gets stuck in a loop of "submitting flow" and "abort signal": This issue highlights problems when tasks enter a retry state, causing flows to loop without progressing. - Tasks stuck in AwaitingConcurrencySlot: This issue involves tasks getting stuck due to concurrency limits and server state mismatches. 2. Documentation Insights: - The Prefect source code, particularly in

flow_engine.py

, suggests that handling exceptions and state transitions are critical. If a flow is already in a pending state, forcing orchestration to update the state name might be necessary. - In

states.py

, manual state creation is possible, but it’s important to ensure that state details like

flow_run_id

are managed correctly. Manual State Transition: While it's technically possible to manually adjust states in the database, it is not recommended without a deep understanding of Prefect's internal state management. Doing so could lead to inconsistent states or further issues. Recommendations: - Double-check your flow's dependencies and parameters. Ensure there are no validation errors causing the flow to remain in a pending state. - Investigate any server or network issues that might be affecting state transitions. - If you must manually adjust states, consider reaching out to Prefect support or consulting with someone familiar with Prefect's internals to avoid unintended consequences. For more detailed information, you might want to explore the Prefect documentation or the specific GitHub issues mentioned above.

@Marvin what should the db be updated with to restart the jobs ?

Updating the database directly to restart jobs in Prefect is not a straightforward task and is generally not recommended. However, if you must proceed, here are some insights and steps to consider: 1. State Transition: - Flows in Prefect transition through states such as

Pending

,

Running

,

Completed

, etc. You would need to change the flow's state from

Pending

to a state that allows it to be picked up by workers, typically

Running

. - This involves setting the state in the database to

Running

, but it must be ensured that all associated metadata is correct. 2. Database Schema: - You must understand the database schema where the flow states are stored. Typically, this involves tables that track flow runs and their states. - Ensure that any foreign keys or related tables are updated accordingly to maintain database integrity. 3. Potential Risks: - Directly modifying the database can lead to inconsistencies if not done correctly. Prefect's state management might rely on additional checks and balances that are bypassed by manual changes. - It's crucial to back up the database before making any changes to avoid data loss. 4. Alternative Approaches: - Instead of manual updates, consider using Prefect's API or CLI to cancel and restart the flow runs. This ensures state transitions are handled correctly by the system. For more detailed guidance and to avoid potential pitfalls, consulting with someone familiar with Prefect's internal architecture or reaching out to Prefect support is advisable. If you're determined to proceed, a deep dive into the Prefect source code might provide additional insights into how states are managed programmatically.

How can I optimize this query? UPDATE deployment SER last_polled=$1: :TIMESTAMP WITH TIME ZONE, status=$2: :deployment_status, updated=now() WHERE deployment.id IN (NULL) AND (1 !=1 1) OR deployment.work_queue_id IN ($3: :UUID)