Retryable errors

[askbeka]

Hi, I am wondering about error handling, in particular errors that result from connection issues and retrying is safe.
Is there any guidance on that?
For example sqlx::Error::Io(Error) seem to be retryable according to description.

[abonander]

It depends on what was being done on the connection at the time the error occurred. If a mutating query (INSERT, UPDATE, DELETE or any schema-modifying statements) was sent to the database server and then the error occurred while waiting for the response, then you probably don't want to retry the operation because the changes called for by the query would have already been applied.

In our applications we generally treat any sqlx::Error as fatal, e.g. for web applications we kick back a 500 Internal Server Error. The one exception is constraint violation errors, but we usually just turn those into a client error like 409 Conflict (for UNIQUE constraint violations).

[askbeka]

Thanks @abonander. I was more interested in connection errors, in case DB is down or timeouts or issues not related to work done with DB itself. Those can be retried. But I dont know which are those errors in sqlx