session存储在数据库和memcache中的问题
在往数据库和memcache中存session信息时出现下面的警告，信息存不进去，这个问题怎么解决
Warning: Invalid callback Session_mem::write, class 'Session_mem' not found in Unknown on line 0
Warning: Unknown: Failed to write session data (user). Please verify that the current setting of session.save_path is correct (C:/temp) in Unknown on line 0
Warning: Invalid callback Session_mem::close, class 'Session_mem' not found in Unknown on line 0
