peewee.InterfaceError: (0, '') | pymysql.err.InterfaceError: (0, '')

I am encountering this exception (using high-level api) then my asyncio based daemon is idle (about 15 minutes or so), after that time, this exception occurs, I have tried to close and reopen connection, and was surprised that Manager (high-level api) did not track its state (close/reopen is done using its methods).

after reopening a connection I’ve got stuck with a bunch of coroutines waiting for resolution which obviously will never come. =(

1. can it be a bug in pymysql/peewee
2. propose add connection status tracking to high-level Manager

any thoughts on how to fix that?

Traceback (most recent call last):
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee.py", line 3748, in execute_sql
warehouse_1        |     cursor.execute(sql, params or ())
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/pymysql/cursors.py", line 166, in execute
warehouse_1        |     result = self._query(query)
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/pymysql/cursors.py", line 322, in _query
warehouse_1        |     conn.query(q)
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/pymysql/connections.py", line 851, in query
warehouse_1        |     self._execute_command(COMMAND.COM_QUERY, sql)
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/pymysql/connections.py", line 1067, in _execute_command
warehouse_1        |     raise err.InterfaceError("(0, '')")
warehouse_1        | pymysql.err.InterfaceError: (0, '')
warehouse_1        | 
warehouse_1        | During handling of the above exception, another exception occurred:
warehouse_1        | 
warehouse_1        | Traceback (most recent call last):
warehouse_1        |   File "/opt/app/storage/sql.py", line 357, in _wrapper_catch_db_excetions
warehouse_1        |     return await fn(*args, **kwargs)
warehouse_1        |   File "/opt/app/storage/sql.py", line 415, in update
warehouse_1        |     await self._manager.create(Item2Source, item_id=existing.id, source_id=source.id)
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee_async.py", line 183, in create
warehouse_1        |     pk = inst._get_pk_value()
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee.py", line 5017, in _get_pk_value
warehouse_1        |     return getattr(self, self._meta.primary_key.name)
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee.py", line 1553, in __get__
warehouse_1        |     for field_name in self.field_names])
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee.py", line 1553, in <listcomp>
warehouse_1        |     for field_name in self.field_names])
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee.py", line 1363, in __get__
warehouse_1        |     return self.get_object_or_id(instance)
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee.py", line 1354, in get_object_or_id
warehouse_1        |     obj = self.rel_model.get(self.field.to_field == rel_id)
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee.py", line 4900, in get
warehouse_1        |     return sq.get()
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee.py", line 3161, in get
warehouse_1        |     return next(clone.execute())
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee.py", line 3213, in execute
warehouse_1        |     self._qr = ResultWrapper(model_class, self._execute(), query_meta)
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee.py", line 2892, in _execute
warehouse_1        |     return self.database.execute_sql(sql, params, self.require_commit)
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee_async.py", line 1024, in execute_sql
warehouse_1        |     return super().execute_sql(*args, **kwargs)
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee.py", line 3755, in execute_sql
warehouse_1        |     self.commit()
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee.py", line 3578, in __exit__
warehouse_1        |     reraise(new_type, new_type(*exc_args), traceback)
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee.py", line 135, in reraise
warehouse_1        |     raise value.with_traceback(tb)
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/peewee.py", line 3748, in execute_sql
warehouse_1        |     cursor.execute(sql, params or ())
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/pymysql/cursors.py", line 166, in execute
warehouse_1        |     result = self._query(query)
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/pymysql/cursors.py", line 322, in _query
warehouse_1        |     conn.query(q)
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/pymysql/connections.py", line 851, in query
warehouse_1        |     self._execute_command(COMMAND.COM_QUERY, sql)
warehouse_1        |   File "/usr/local/lib/python3.5/site-packages/pymysql/connections.py", line 1067, in _execute_command
warehouse_1        |     raise err.InterfaceError("(0, '')")
warehouse_1        | peewee.InterfaceError: (0, '')

[Xandaros]

I am also encountering this. I use flask with socketio, which, as far as I know, uses coroutines or something similar. Maybe it is connected to async, after all?

I am not using anything fancy from peewee - just the high level API. And indeed, it happens after long idle time.

Edit: Looks like I got the wrong repo, I’m actually using normal peewee. This is still an issue for me, though. Maybe this will help you narrow it down.

[dikderoy]

my test is designed to show what bug appears in simple, real-world scenario, “crazy-monkey method” to speed up tests - is just a way of getting work done faster =)

Here is another thing which can help to track the cause - in all variations of code and execution graphs - it always fail while working with Item2Source - which is not like other 2 models - it is a many2many table relation (composed of 2 foreignkey fields and having them as composite pk)

I am not familiar with peewee internals but it looks connected.