[Zope] nonlinear response times on multiple concurrent requests for same data

[Sean Hastings]

I have a report page that when going through the maximum amount of data
takes maybe 5 seconds to generate on both my Linux server and on the Windows
machine I use for development. This report page is a Page Template generated
from external product code. There is no external database involved - just
Zope objects.

I was getting weird periods of serious slowdown on my server, and traced the
problem to multiple users running this report at the same time.

On the windows machine, if I generate 4 requests, the time to return all of
them is approximately 20 seconds or x*N response time. On the Linux machine,
however, I seem to be seeing MUCH longer response times for simultaneous
requests for the same data. Could this be an issue with the way in which I
have Zope configured on the server? or does the Linux version do something
differently?

I have seen hints of "read only" transactions, but have not been able to
figure out how to code these. Is there something I could do to make these
read requests for the same data not interfere with each other?

--Sean