[mod_python] scalability question?

Worker MPM, but identical on both machines.

> -----Original Message-----
> From: Graham Dumpleton [mailto:graham.dumpleton at gmail.com]
> Sent: Thursday, April 03, 2008 4:13 AM
> To: Alec Matusis
> Cc: mod_python at modpython.org
> Subject: Re: [mod_python] scalability question?
> 
> What Apache MPM is each server compiled with, prefork or worker MPM?
> 
> Graham
> 
> On 03/04/2008, Alec Matusis <matusis at yahoo.com> wrote:
> > I just installed a second webserver machine. About 1/3 of all http
> requests
> >  are now routed to this new webserver, which has identical
> configuration to
> >  the first webserver.
> >  Both webservers connect to a single DB server.
> >
> >  On the new webserver I am intermittently getting the following
> error:
> >  OperationalError: (2003, "Can't connect to MySQL server on
> '10.18.3.0' (4)")
> >
> >  What puzzles me is that the old webserver did not have this error
> under 70%
> >  higher request rate (at 600 req/sec), before some of the load was
> removed
> >  from it. Mod_python/python installation is identical on both boxes,
> and they
> >  are running exactly identical scripts. TCP stack also seems to be
> configured
> >  identically.
> >  When I got a bunch of these errors, I did notice about 15000
> connections to
> >  the database in TIME_WAIT state on this problematic new webserver.
> The new
> >  machine is a bit slower (2x2.66GHz xeon vs 2x3.0GHz on the old one),
> but
> >  would this small difference cause such a problem?
> >
> >  The script that connects to the DB is:
> >
> >  def load(self):
> >        .....
> >         dbc = MySQLdb.connect(host=config.db_host, db=config.db,
> >  user=config.db_user, passwd=config.db_passwd )
> >         dbc.autocommit(True)
> >         c = dbc.cursor()
> >         r = c.execute( query)
> >         if r == 0: #not sure what the key error is supposed to be but
> it is
> >  being caught
> >             raise ProfileError
> >
> >         rvalues = c.fetchone()
> >         c.close()
> >         dbc.close()
> >           ....
> >
> >
> >  I am very puzzled what may cause this...
> >
> >
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