[Seaside-dev] supporting vm routes

[Philippe Marschall]

2008/12/4, Ramon Leon <ramon.leon at allresnet.com>:
>>
>> Setting up a cluster with four images could look something like this:
>>
>> <Proxy balancer://mycluster>
>> 	Order deny,allow
>> 	Allow from all
>>
>> 	BalancerMember http://127.0.0.1:8080/ loadfactor=1
>> route=33 min=1
>> max=50 keepalive=On
>> 	BalancerMember http://127.0.0.1:8080/ loadfactor=1
>> route=34 min=1
>> max=50 keepalive=On
>> 	BalancerMember http://127.0.0.1:8080/ loadfactor=1
>> route=35 min=1
>> max=50 keepalive=On
>> 	BalancerMember http://127.0.0.1:8080/ loadfactor=1
>> route=36 min=1
>> max=50 keepalive=On
>>
>> </Proxy>
>> ProxyPreserveHost On
>> ProxyPass /seaside balancer://mycluster/seaside STICKYSESSION=_s|_s
>> nofailover=On
>> ProxyPassReverse /seaside balancer://mycluster/seaside
>>
>> To support this in Seaside we need to change the session key
>> generation. We need to be able to append a suffix that is configured
>> in the application. Julian you've spent a lot of time on sessions and
>> cache and stuff. What do you think is the best way to implement this?
>> A WAClusteredApplication that has a WARouteCache?
>>
>> How do other people feel about this? Is this useful? Should this be
>> part of Seaside out of the box or rather be an addon like
>> Seaside-Cluster?
>
> I used to do that but frankly ProxyBalancer sucks; it makes rolling out new
> code very hard because you can't just dynamically fire up a bunch of new
> servers and shift the traffic.

You can do this is a limited way a balancer manager [1] (have workers
in stopped modus).

To be fully dynamic you need mod_cluster with "dynamic discovery" and
"pluggable load computation" [2]. Replace "AS instance" and "JBossWeb"
with Smalltalk image and it's easier to understand ;-)

 [1] http://httpd.apache.org/docs/2.2/mod/mod_proxy_balancer.html#enable
 [2] http://www.jboss.org/community/docs/DOC-11431

Cheers
Philippe