cocoon-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Sylvain Wallez <sylvain.wal...@anyware-tech.com>
Subject Re: SoC between flow and sitemap
Date Tue, 20 May 2003 06:25:44 GMT
Stefano Mazzocchi wrote:

>on 5/19/03 5:39 PM Bruno Dumon wrote:
>
>  
>
>>On Mon, 2003-05-19 at 23:28, Sylvain Wallez wrote:
>>[...]
>>
>>    
>>
>>>Yes, but you have to consider how this is actually implemented. If you 
>>>put a farm of Tomcats behind an httpd with mod_jk, you will be 
>>>guaranteed that requests for a given session will always be handled by 
>>>the same Tomcat instance. This is called session affinity. But Tomcats 
>>>don't communicate with each others to exchange session or application data.
>>>
>>>This means that if a continuation ContA is created on Tomcat TC1, all 
>>>subsequent requests referencing this continuation must be handled by the 
>>>same TC1, and not TC2, since ContA doesn't exist on TC2. And the only 
>>>means you have to achieve this if servlet engines don't communicate is 
>>>through session affinity.
>>>
>>>So continuations must be bound to sessions.
>>>
>>>      
>>>
>>Actually mod_jk only looks at a suffix appended to the session cookie,
>>and it shouldn't be too difficult to hack mod_jk to use a different
>>cookie especially for this purpose. So sessions are not really required
>>for this.
>>    
>>
>
>What about BEA weblogic, IBM webshere, Oracle appserver, etc, etc, etc?
>
>Hypothetical chat between a CTO and a cocoon proponent:
>
> - cocoon? we are interested at it, but is it fast?
> - the pipeline creation is very complex and can be much slower than
>text-based tecnologies, but cocoon has a very good caching mechanism
>that allows to reuse all possible content and provide your own caching
>logic to components if you need to. The results in real life prove
>cocoon to be highly efficient. In a highly critical environment (which I
>can't name), the use of cocoon proved to be orders of magnitude faster
>than a rival application based on Oracle Internet File System.
>
> - what about static stuff? cocoon is much slower than a web server!
> - yes, but I normally suggest to put a transparent proxy up front and
>cocoon will serve static content only once, the remaining it done by the
>proxy lightning fast. (it is also transparent if you have dynamically
>generated resources like images, flash files or CSS stylesheets and
>allows to maintain all your URI space in one comfortable location)
>
> - hmmm, ok, but does it scale for dynamic stuff?
> - sure, for a stateless cocoon environment, you can throw silicon at it
>and balance the load transparently by replicating the cocoon environment
>on different machines. A european company (which I can't name) did tests
>that showed 12000 req/sec on a big clustered environment.
>
> - cool, but what about stateful cases, expecially with the flow and
>this new continuation thing, does it scale?
> - only with tomcat and mod_jk
>
> - ok, we'll use struts then.
>  
>

Sad, but so true.

Moreover, from a Cocoon developper point of view, we (at least I) don't 
want to write and maintain a Cocoon-specific fork of mod_jk.

So let's use what the servlet engines give us, even if that means using 
sessions which could theoretically be avoided but which are actually 
used by most web applications.

Sylvain

-- 
Sylvain Wallez                                  Anyware Technologies
http://www.apache.org/~sylvain           http://www.anyware-tech.com
{ XML, Java, Cocoon, OpenSource }*{ Training, Consulting, Projects }



Mime
View raw message