No, I don't use gevent anymore, everything goes from engine, you can see I have a direct_engine=True to control
在 2014年3月14日星期五UTC+8下午12时22分09秒，Michael Bayer写道： > > > On Mar 13, 2014, at 11:51 PM, Ni Wesley <[email protected] <javascript:>> > wrote: > > > Hi all, > > I hit a problem that cannot use the connection pool effectively. > > > > messages_writer = DBWriter('messages') > > connection_writer = DBWriter('sessions_details') > > messages_details_writer = DBWriter('messages_details') > > > > > > In other place, I call the connection_writer to do rapid db operations. > > For example, keep operatons rapidly. > > > > And, I watch from the client by netstat -anpto|grep mysql_server_ip|wc > -l > > > > I see the number is always 1 or 2. > > the code you sent does not do anything concurrently? it only has code > referring to “gevent”, but that code is all commented out. > > if you’d like to see a connection pool open more than two connections, run > this program: > > from sqlalchemy import create_engine > > e = create_engine(“mysql://scott:tiger@localhost/test”) > > conn1 = e.connect() > conn2 = e.connect() > conn3 = e.connect() > > raw_input(‘take a look at your netstat now’) > > > run your netstat in a separate window at the prompt, and you’ll see three > connections open. > > Add this: > > conn4 = e.connect() > > then you’ll see four. Simple right? > > that’s all I can give you. There is nothing mysterious going on, so as > to why your program isn’t concurrent, I have no idea, you aren’t really > sharing the actual program here (and you don’t have to, I don’t have time > to debug a whole gevent program). > > But SQLAlchemy likely has nothing to do with the issue. If it does, you’d > need to boil it down to a simple test case that any of us can run which > confirms a specific issue in SQLAlchemy. Maybe QueuePool locks in some > funny way with gevent (noone has reported that, but it does have some > mutexes in there on checkout and I’ve no idea what mutexes do when you’re > using gevent). Try using NullPool instead then. That’s about it. Or > just use a straight MySQL connection and cursor, this program is so > simplistic running just three SQL statements, I think you’ll find if you > run it using no SQLAlchemy at all, it will do exactly the same thing with > the same concurrency/performance issues. > > > > Actually, the other script who is calling db opeartion is slow, why the > tcp connections not increased to improve the performance? > > As I said I’ve not used gevent very much, maybe gevent has a community > that can be consulted also. > > > -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
