[Zope] ADVICE needed: multi-site Zope installations, PCGI and ZServer

[Tony McDonald]

Hi all,
I'd like to gather the collective wisdom of the list on this 
situation I need to sort out;

1) We run Apache with lots of virtual servers. Within the virtual 
servers I have Rewrite rules that point to various subfolders of a 
Zope 1.10.3 installation, which uses PCGI. Each one of the subfolders 
corresponds to a site that shares a set of core DTML, ZSQL and 
External methods, along with their customizations specific to that 
subfolder (subsite).

2) This works, but the manage screens for the subsites are mangled, 
which can lead the admins of those sites getting very confused. I 
understand that this is something that can only be fixed in the 
innards of ZPublisher, ie beyond my ken.
   [DC guys - this is definitely a pain for those wanting to run 
several subsites from a single Zope installation, thus taking care of 
shared methods etc.]

3) I'm also running a Zope 2.0.0 system on a higher port number using 
ZServer (ie bypassing the Apache server entirely). I'm in the process 
of shifting parts of the 1.10.3 site to this 2.0.0 site. This site is 
quite fast and I'm pleased with it. The intention is to run the main 
site and the subsites from this installation.

4) What I *want* to do is save the effort of exporting  (and keeping 
up to date!) to different installations of Zopethe various core 
methods I have in the 1.10.3 installation, whilst at the same time 
allowing the virtual hosts to point to subfolders in the main 
distribution. I also want maximum speed and to be able to keep all my 
Zope products *for all the subsites* in one place. (I want, I 
want....)

5) If I understand it correctly, if I use Apache to manage the 
virtual servers I *have* to use PCGI rather than ZServer. PCGI is 
approximately 4 times slower than ZServer (this from a Jason Thaxter 
email of 1/9/99)
"While many benchmarking stats are meaningless, I can support Amos' basic
contention that zerver is about 4x faster that apache/pcgi/zerver."

My questions are:
Can I *somehow* use Apache to manage the virtual hosts (passing on 
the authentication headers) to a ZServer based Zope instance. This 
way I get Apache logging and other benefits?
Can I split this instance into subsites that get less confused 
management screens?
As I'm using MySQL as my database adapter, which is currently not 
thread-safe, am I better off just creating these subsites separately 
and running three or four different Zope instances?
Should I use the SOFTWARE_HOME and INSTANCE_HOME variables to run 
several Zope instances (each containing what would be a subsite), but 
only one software instance, thus keeping all my External methods and 
Products in one place? (and if so, any pointers on how to do this 
would be great)

any thoughts on this would be appreciated.
Cheers
tone.
------
Dr Tony McDonald,  FMCC, Networked Learning Environments Project 
http://nle.ncl.ac.uk/
The Medical School, Newcastle University Tel: +44 191 222 5888
Fingerprint: 3450 876D FA41 B926 D3DD  F8C3 F2D0 C3B9 8B38 18A2