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From Jeffrey Burgoyne <burgo...@keenuh.com>
Subject Re: [proxy] New implementation ready for testing
Date Mon, 16 Aug 2004 13:10:40 GMT
I've been following the changes to mod_proxy and have been absolutely
estatic as to where everything is headed and what is being done. I've been
working with a very large client for two years changing their whole
architectuer and using an Apache front end employing mod_proxy to their
backend technologies, which is just about everything under the sun.

I have a few comments on the direction this thread is following. Some may
be more to my ignorance as I've only been looking at these threads deeply
for the past two weeks (as the client is finally convinced to move to
apache 2 from the 1.3 series).


The first one is this method as prescribed above does not seem to have a
failover mechanism, i.e. if connection to one server fails, then the next
in line is tried. This is quite important for mission critical
installations.

The second is that while pure randomness is better than nothing, some
weighting system has significant advantages. The first one, from my
perspective, is the ability to define a back end primary and secondary
service. For example, if I could weight one server at 100 and another at
0, then the primary server would always be called, unless it went down and
then the secondary server would be called.

While tying this all in with mod backhand is good as suggested, perhaps
even simpler would be a least connections test. I'm deploying an Alteon
front end to the Apache web server for the client, and wghen investigating
all the options available for load balancing, least connections definitely
won out. In thecase of connecting to a back end app server I can see where
it is not as good, but is relatively simple to implement. I suppose it
would also have to be "least active connections" if the connection pooling
gets done.

Another consideration for the future is handling all of this when you are
running mutliple servers with Apache up front in a load balanced
enviornment. I am currently deploying an IBM blade center which
equivelantly is 14 PC's sharing some common resources, but not memory.
Whether in load balancing or connection pooling it would be nice to have
some level of communication between the blades to ensure the system runs
more smoothly.

Lastly, iI feel if I am going to make some recommendations, I should
contribute something back. While I am not comfortable with the time I have
available to help with coding, I can easily commit to some testing and
verification time as soon as I have my test blade center up.

Cheers, and thanks for the good work everyone.


Jeffrey Burgoyne

Chief Technology Architect
KCSI Keenuh Consulting Services Inc
burgoyne@keenuh.com

On Mon, 16 Aug 2004, Graham Leggett wrote:

> Pier Fumagalli wrote:
>
> > What's wrong with:
> >
> > ProxyPassReverse / http://localhost:8888/
> > ProxyPreserveHost On
> > RewriteMap hosts rnd:/opt/apache/conf/tables/hosts.map
> > RewriteRule "^/(.*)" "${hosts:live}/$1" [P,L]
>
> It isn't very elegant though. Someone who is well versed in mod_rewrite
> and regular expressions might find it really easy, but the rest of us
> mortals won't. :(
>
> Regards,
> Graham
> --
>

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