On Windows platforms, what's the rule of thumb (or what are the
trade-offs)
when hosting multiple web sites on a machine, between setting up a
separate
httpd.conf file for each site versus setting up multiple virtual hosts
within a single httpd.conf file?

Obviously the former gives you the ability to start & stop them
independently, but what are the performance trade-offs?  What is the more
common approach?

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Virtual hosts are the most common approach.

samccauley@us.ibm.com wrote:
>
> On Windows platforms, what's the rule of thumb (or what are the trade-offs
)
> when hosting multiple web sites on a machine, between setting up a separat
e
> httpd.conf file for each site versus setting up multiple virtual hosts
> within a single httpd.conf file?
>
> Obviously the former gives you the ability to start & stop them
> independently, but what are the performance trade-offs?  What is the more
> common approach?

[ Post a follow-up to this message ]

Ray, Sam,

Yes, the most common approach is probably a single installation, as it's
easier to setup and requires fewer resources, but there are some advantages
to using multiple instances in an enterprise.

The key benefits, that I've found, are around the ability to separate
running instances for different products/business units. They are:
- Enhanced Security: This ensures that security for each product can be
implemented in a least privilege manner. (Ie. Don't load a module needed for
one site for all sites, etc)
- Improved Stability: Issues with one running instance may not impact
the other instances. (Unless it crashes the physical machine. Win2003EE can
use Windows System Resource Manager [WSRM] to control process-level reso
urce
usage.)
- Reduced Administration: If you've ever tried to agree an outage with
many different 'service owners' because one product wants a config change,
etc., you'll understand. They can be restarted independently without
impacting the others. The log files are also separated, making it easier for
usage reporting and product-specific troubleshooting.
- Efficient Support: Extended logging can be enabled per service, again
without having to agree a restart time with all services, allowing instance
specific verbose logging.

Don't get me wrong, there are also some downsides to this approach:
- Increased Administration: Requires more effort to plan and setup.
Note: You could use junction (www.sysinternals.com) to implement this
scenario using only one set of binary installs. While this can be achieved
without junctions, this allows a path for upgrading each service by just
changing junction destinations.
Note2: Using junction could just be an overly complicated waste of time.
- Additional Monitoring Requirements: More running instances requires more
monitoring.
- Additional Resource Requirements: The more instances running, the more
resources required.

Just a few thoughts.

Hope this helps,

CharlyOz.




"Ray McVay" <raymmailbox-news@yahoo.com> wrote in message
news:d8b671$4h4k$2@news.boulder.ibm.com...[vbcol=seagreen]
> Virtual hosts are the most common approach.
>
> samccauley@us.ibm.com wrote: 

[ Post a follow-up to this message ]

CharlyOz wrote:

>     - Enhanced Security: This ensures that security for each product can b
e
> implemented in a least privilege manner. (Ie. Don't load a module needed f
or
> one site for all sites, etc)

We run two instances of Apache on our external server, much to the
chagrin of the admin.  One is a standard, latest version Apache that
runs at least a couple of virtual hosts. The other is the creaky old IBM
Apache required to do HTTPS and remote OSE back to the steam powered WAS
3.5 app server on the inside. It all works quite well and is generally
very stable.

>     - Improved Stability: Issues with one running instance may not impact
> the other instances. (Unless it crashes the physical machine. Win2003EE ca
n
> use Windows System Resource Manager [WSRM] to control process-level re
source
> usage.)

Uh, luckily the above is a Linux box but the app server it feeds is NT4
so the web server is much more stable than the app server. :D

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> They can be restarted independently without
> impacting the others.
apachectl restart / apache -k restart will ensure there is no interruption
of service.

> The log files are also separated, making it easier for
> usage reporting and product-specific troubleshooting.
CustomLog is a VirtualHost directive, so you could separate log files that
way (not tested myself :-).

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Ben_ wrote: 
>
> CustomLog is a VirtualHost directive, so you could separate log files that
> way (not tested myself :-).

I've done that one.

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