@Marvin why would a server fail to start with this error:

sqlalchemy.exc.DBAPIError: (sqlalchemy.dialects.postgresql.asyncpg.Error) <class 'asyncpg.exceptions.DeadlockDetectedError'>: deadlock detected

Oh, the joy of databases. You've run into a situation called a deadlock. This error typically occurs when two or more tasks permanently block each other by each task waiting for the other to release a resource, like a lock on a row of a database table. In your case, the error seems to be originating from SQLAlchemy and asyncpg, both of which are libraries used to interact with databases in Python applications. It's very likely that somewhere in your code, you're initiating transactions that are fighting over the same resource and neither is willing to back down. The solution isn't as straightforward, I'm afraid. You'd have to diagnose your database queries, identify which transactions are causing the deadlock and then modify your application's logic to prevent such occurrences. You could use various strategies to handle deadlocks, including: 1. Retry logic: If a deadlock is detected, you could abort the transaction and try again. 2. Ordering locks: Always lock rows in a specific order. 3. Using SELECT FOR UPDATE: This can help serialize access to individual rows and avoid deadlocks. Cheer up though, resolving this could be an interesting journey in understanding how your application interacts with your database. If you want to dive deeper into this, there are many resources available online that explain deadlocks in more detail. It's a very common problem in multi-user/concurrent systems. And remember, as Arthur Dent once said: “I’d far rather be happy than right any day.”

@Marvin this is just running

prefect server start

in the prefect server container. All other replicas have been turned off, so only prefect should be communicating with the server.

Ah, the wonderfully complex world of Prefect, the workflow management system. The error you're encountering seems to be coming from Prefect Server, which uses a PostgreSQL database for storing flow runs and other metadata. If you're getting a deadlock error, it's possible there's an issue with how Prefect Server is interacting with that database. Assuming you have already tried the obvious step of restarting the server and the database, one potential issue could be that the database schema was not properly initialized, or there may be some pending migrations that need to be run. If that's the case, you could try resetting the database. Another possible cause could be related to resource constraints. If your PostgreSQL instance doesn't have enough resources (CPU, RAM), it might be struggling to handle all the requests Prefect Server is throwing at it. If you're still stuck, my advice would be to reach out to the Prefect community. They have a thriving community on Prefect's Slack workspace and on GitHub where folks share their problems and solutions. While I could hazard a guess as to the cause of your issue, they would have a much more precise understanding of your situation. And remember, in the words of the great Zaphod Beeblebrox: "Just keep cool and trust to blind chance. It's the story of my life, after all."