[Zope] zope2.2.0 and what is high load

[Chris McDonough]

> On Fri, 11 Aug 2000, Chris McDonough wrote:
> > > i went to each Zeo client control_panel, and see that there's
> > > a mzximum of
> > > four connections open at any given time.
> >
> comments to the above.  i saw only four threads because i 
> started that 
> particular box with the default.  on the box with -t25, i see 7 open 
> connections at any given time.  sorry, my mistake.

Oh, ok... that makes more sense.

> > You may want to ramp your number of threads down to 5 
> (-t5).  25 doesn't
> > do much for you because only 7 threads can be using 
> database connections
> > at any given time.  The high number of threads you're 
> servicing might
> > actually be slowing things down as they contend for 
> available database
> > connections.
> >
> will do.  and hope to see that it does something.

Based on your findings that all 7 DB connections are being used, I'd
revise the number of threads to 8.

> > It doesn't seem as if bumping your number of database 
> connections will
> > do us any good here, because it doesn't seem you're using 
> all 7.  I'm
> > not sure *why* you're not using all 7, because you've got 
> at least 15
> > processes waiting around just on your top screen for DB connections.
> 
> i did some grepping and saw the magical number 7 in 
> ZODB/DB.py.  is that the 
> number to turn up if i wanted to try increasing the db pool 
> connection?  i do 
> have postgresql with ZPygreSQL.  will that have anything to 
> do with what i'm 
> facing?

Yes, it's the pool_size parameter.  You can increment this value
*carefully* if you see that you have more threads hanging around than DB
connections, like you're seeing now.  I have no idea what this will do
to your relational stuff.

The "right thing to do" is to test this outside of production.  I don't
want to tell you to go ahead and muck around on a production server.
But if it were *me*, I might be tempted to:

- First, lower the number of threads via -t8 and see what effect that
has on speed.

- If that doesn't solve anything, bump up both the NUMBER_OF_THREADS and
the pool_size up to 10 or 12, then do some checking, and see if you
still have threads waiting for a DB.  Continue doing this in increments
of 2 or 4, making notes as you go.

Note that if it breaks your site, I'll deny I ever gave you this advice.
:-)  Proceed at your own risk.

> i love zope, and open source in general, and i can't bear 
> having to switch to 
> using something i don't really like. 

Geez, I hope not.  This is an eminently solveable problem.