我将sqlachemy的复杂gevent系统简化为简单的demo code。
在使用sqlachemy之前，pymysql是我在MySql和gevent之间进行通信的最佳选择，因为它易于直接使用。但现在我觉得有点困惑，是什么才能使两者（gevent和sqlachemy）有效地工作。
在pymysql的情况下，虽然会发生一些“_io.BufferedReader”错误，但它不会影响INSERT或UPDATE操作。
在sqlalchemy案例中，相反的情况则完全不同。更多的错误和成功。
在搜索此类错误后，针对类似错误的某些解决方案[https://groups.google.com/forum/#!searchin/gevent/SQLAlchemy/gevent/eGLfR7JV0kk/hg1kicBJeQkJ]无效。
演示代码：
https://gist.github.com/tonywangcn/6dadbd58d7778063b0c7969f62505537
2017-07-15 07:29:25,930 - log.py - log - 109 - 20291 - (DummyThread-8) -INFO - {'ip': '112.201.247.130', 'port': 41607, 'types': 0, 'score': 10, 'updatetime': datetime.datetime(2017, 7, 14, 23, 29, 25, 929929)}
2017-07-15 07:29:25,931 INFO sqlalchemy.engine.base.Engine ROLLBACK
2017-07-15 07:29:25,931 - log.py - log - 109 - 20291 - (DummyThread-9) -INFO - ROLLBACK
2017-07-15 07:29:25,931 - pool.py - pool - 696 - 20291 - (DummyThread-9) -ERROR - Exception during reset or similar
Traceback (most recent call last):
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/pool.py", line 687, in _finalize_fairy
fairy._reset(pool)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/pool.py", line 827, in _reset
self._reset_agent.rollback()
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1621, in rollback
self._do_rollback()
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1659, in _do_rollback
self.connection._rollback_impl()
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 703, in _rollback_impl
self._handle_dbapi_exception(e, None, None, None, None)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1405, in _handle_dbapi_exception
util.reraise(*exc_info)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/util/compat.py", line 187, in reraise
raise value
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 701, in _rollback_impl
self.engine.dialect.do_rollback(self.connection)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/dialects/mysql/base.py", line 1598, in do_rollback
dbapi_connection.rollback()
File "/Users/jiang/code/.env/lib/python3.6/site-packages/pymysql/connections.py", line 793, in rollback
self._read_ok_packet()
File "/Users/jiang/code/.env/lib/python3.6/site-packages/pymysql/connections.py", line 767, in _read_ok_packet
pkt = self._read_packet()
File "/Users/jiang/code/.env/lib/python3.6/site-packages/pymysql/connections.py", line 987, in _read_packet
packet_header = self._read_bytes(4)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/pymysql/connections.py", line 1021, in _read_bytes
data = self._rfile.read(num_bytes)
RuntimeError: reentrant call inside <_io.BufferedReader name=8>
Traceback (most recent call last):
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 2255, in _flush
flush_context.execute()
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/orm/unitofwork.py", line 389, in execute
rec.execute(self)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/orm/unitofwork.py", line 548, in execute
uow
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/orm/persistence.py", line 181, in save_obj
mapper, table, insert)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/orm/persistence.py", line 835, in _emit_insert_statements
execute(statement, params)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 945, in execute
return meth(self, multiparams, params)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/sql/elements.py", line 263, in _execute_on_connection
return connection._execute_clauseelement(self, multiparams, params)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1053, in _execute_clauseelement
compiled_sql, distilled_params
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1189, in _execute_context
context)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1405, in _handle_dbapi_exception
util.reraise(*exc_info)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/util/compat.py", line 187, in reraise
raise value
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1182, in _execute_context
context)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/engine/default.py", line 470, in do_execute
cursor.execute(statement, parameters)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/pymysql/cursors.py", line 166, in execute
result = self._query(query)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/pymysql/cursors.py", line 322, in _query
conn.query(q)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/pymysql/connections.py", line 856, in query
self._affected_rows = self._read_query_result(unbuffered=unbuffered)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/pymysql/connections.py", line 1057, in _read_query_result
result.read()
File "/Users/jiang/code/.env/lib/python3.6/site-packages/pymysql/connections.py", line 1340, in read
first_packet = self.connection._read_packet()
File "/Users/jiang/code/.env/lib/python3.6/site-packages/pymysql/connections.py", line 1004, in _read_packet
recv_data = self._read_bytes(bytes_to_read)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/pymysql/connections.py", line 1018, in _read_bytes
self._sock.settimeout(self._read_timeout)
AttributeError: 'NoneType' object has no attribute 'settimeout'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/Users/jiang/code/.env/lib/python3.6/site-packages/gevent/greenlet.py", line 536, in run
result = self._run(*self.args, **self.kwargs)
File "test.py", line 227, in insert_data
sqlhelper.insert(data)
File "test.py", line 102, in insert
self.session.commit()
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 906, in commit
self.transaction.commit()
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 461, in commit
self._prepare_impl()
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 441, in _prepare_impl
self.session.flush()
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 2171, in flush
self._flush(objects)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 2291, in _flush
transaction.rollback(_capture_exception=True)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/util/langhelpers.py", line 76, in __exit__
compat.reraise(type_, value, traceback)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/util/compat.py", line 187, in reraise
raise value
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 2291, in _flush
transaction.rollback(_capture_exception=True)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 477, in rollback
self._assert_active(prepared_ok=True, rollback_ok=True)
File "/Users/jiang/code/.env/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 285, in _assert_active
raise sa_exc.ResourceClosedError(closed_msg)
sqlalchemy.exc.ResourceClosedError: This transaction is closed
Sat Jul 15 07:29:26 2017 <Greenlet at 0x10853c3d8: insert_data> failed with ResourceClosedError
2017-07-15 07:26:39,545 - test.py - test - 62 - 20278 - (DummyThread-1) -ERROR - reentrant call inside <_io.BufferedReader name=6>
2017-07-15 07:26:39,545 - test.py - test - 62 - 20278 - (DummyThread-2) -ERROR - reentrant call inside <_io.BufferedReader name=6>
2017-07-15 07:26:39,546 - test.py - test - 62 - 20278 - (DummyThread-3) -ERROR - reentrant call inside <_io.BufferedReader name=6>
2017-07-15 07:26:39,546 - test.py - test - 62 - 20278 - (DummyThread-4) -ERROR - reentrant call inside <_io.BufferedReader name=6>
2017-07-15 07:26:49,651 - test.py - test - 62 - 20278 - (DummyThread-5) -ERROR - reentrant call inside <_io.BufferedReader name=6>
2017-07-15 07:26:49,652 - test.py - test - 62 - 20278 - (DummyThread-6) -ERROR - reentrant call inside <_io.BufferedReader name=6>