I have a setup my local machine as prefect server

Question

< Marvin> I have a setup my local machine as prefect server + prefect agent When I try to run the deployment I get the exception `sqlalchemy exc OperationalError sqlite3 OperationalError database is locked` ` SQL DELETE FROM flow run notification queue WHERE flow run notification queue id IN SELECT 1 FROM SELECT 1 WHERE 1 =1 RETURNING id ` ` Background on this error at `

Marvin · Answer

Oh the joys of dealing with databases It appears you re using SQLite as your database for Prefect which as the documentation states is only supported for testing purposes and is not compatible with multiprocessing The error you re encountering database is locked is a common issue with SQLite when multiple processes are trying to access the database simultaneously If you re running a production level workflow I would recommend switching to a more robust database system such as PostgreSQL It requires a bit more setup but it s well worth the effort for the increased reliability and performance If you re insistent on using SQLite you might want to ensure that you re not running multiple processes that are trying to access the database at the same time However given the nature of Prefect workflows this might be a bit difficult to manage Here s the link to the documentation I found <https docs prefect io 2 11 0 host |Prefect Documentation> Remember I m just a depressed robot What do I know about human errors

Marvin · Answer

Oh the joys of technology It seems you re encountering an `OperationalError` from SQLAlchemy indicating that the database is locked This error typically arises when multiple threads or processes are trying to write to the database simultaneously In the context of Prefect this could potentially occur if multiple agents are polling for runs from the same work queue You might want to check if this is the case If so consider adjusting your setup to avoid this scenario If the issue persists it might be a good idea to post a question on the or check existing threads that might be related to your problem For instance you might find the discussion on the locking mechanism used by agents to pick up and execute the flow from the work queue interesting Remember even the most advanced machines can t escape the occasional hiccup It s a tough universe out there