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

[MozzieHan]

I am encountering this exception (using peewee-async 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).

Traceback (most recent call last):
  File "/home/ubuntu/dati-server/match/manager.py", line 56, in clean_up_user
    await exam_end_all_handler(current_match_id, user_id)
  File "/home/ubuntu/dati-server/match/manager.py", line 407, in exam_end_all_handler
    match_result = await MatchUserRecord.set_user_score_and_winner(match_id)
  File "/home/ubuntu/dati-server/models/record.py", line 260, in set_user_score_and_winner
    score1 = await user_record1.get_match_score()
  File "/home/ubuntu/dati-server/models/record.py", line 108, in get_match_score
    answer_records = await objects.execute(UserAnswerRecord.filter(match_id=self.match.id, user_id=self.user_id))
  File "/home/ubuntu/dati-server/env/lib/python3.6/site-packages/peewee.py", line 1386, in __get__
    return self.get_object_or_id(instance)
  File "/home/ubuntu/dati-server/env/lib/python3.6/site-packages/peewee.py", line 1377, in get_object_or_id
    obj = self.rel_model.get(self.field.to_field == rel_id)
  File "/home/ubuntu/dati-server/env/lib/python3.6/site-packages/peewee.py", line 4988, in get
    return sq.get()
  File "/home/ubuntu/dati-server/env/lib/python3.6/site-packages/peewee.py", line 3220, in get
    return next(clone.execute())
  File "/home/ubuntu/dati-server/env/lib/python3.6/site-packages/peewee.py", line 3274, in execute
    self._qr = ResultWrapper(model_class, self._execute(), query_meta)
  File "/home/ubuntu/dati-server/env/lib/python3.6/site-packages/peewee.py", line 2939, in _execute
    return self.database.execute_sql(sql, params, self.require_commit)
  File "/home/ubuntu/dati-server/env/lib/python3.6/site-packages/peewee_async.py", line 1041, in execute_sql
    return super().execute_sql(*args, **kwargs)
  File "/home/ubuntu/dati-server/env/lib/python3.6/site-packages/peewee.py", line 3837, in execute_sql
    self.commit()
  File "/home/ubuntu/dati-server/env/lib/python3.6/site-packages/peewee.py", line 3656, in __exit__
    reraise(new_type, new_type(*exc_args), traceback)
  File "/home/ubuntu/dati-server/env/lib/python3.6/site-packages/peewee.py", line 135, in reraise
    raise value.with_traceback(tb)
  File "/home/ubuntu/dati-server/env/lib/python3.6/site-packages/peewee.py", line 3830, in execute_sql
    cursor.execute(sql, params or ())
  File "/home/ubuntu/dati-server/env/lib/python3.6/site-packages/pymysql/cursors.py", line 165, in execute
    result = self._query(query)
  File "/home/ubuntu/dati-server/env/lib/python3.6/site-packages/pymysql/cursors.py", line 321, in _query
    conn.query(q)
  File "/home/ubuntu/dati-server/env/lib/python3.6/site-packages/pymysql/connections.py", line 859, in query
    self._execute_command(COMMAND.COM_QUERY, sql)
  File "/home/ubuntu/dati-server/env/lib/python3.6/site-packages/pymysql/connections.py", line 1075, in _execute_command
    raise err.InterfaceError("(0, '')")
peewee.InterfaceError: (0, '')

[coleifer]

This looks like a bug in peewee-async or something? Some server issue?

Peewee is tested with mysql every release (and every commit for that matter) so I know mysql isn't horribly broken or anything.

[amirouche]

The follow up is at https://github.com/05bit/peewee-async/issues/26

[amirouche]

We encounter the same problem with peewee with use recent flask version 1.0.2 without relying on flask-peewee.

We do not open/close connection between each request, I was expecting to be able to reuse the connection across request.

We do not use the connection pool.

[amirouche]

I think we found the issue. Looking up earlier log, we noticed mysqld server closed the only connection we had and we did not reconnect after.

ref: http://docs.peewee-orm.com/en/latest/peewee/database.html#error-2006-mysql-server-has-gone-away
ref: http://docs.peewee-orm.com/en/latest/peewee/database.html#flask

Ty!