--- Peter Donald <[EMAIL PROTECTED]> wrote:
> On Wed, 12 Mar 2003 08:13, sadaf zargeen wrote:
> > Is there any plans to make Avalon/Phoneix Fault
> > tolerant or build loading-balancing into it or is
> that
> > too application specific to be part of the
> framework.
> 
> That is usually application/domain specific though
> we have talked about 

where?  Wiki or mailing list, cause I couldn't find
anything on mailing list.


> implementing it before. Any ideas?
> 

Well just some questions within the context of the
application I am working on that requires failover and
loadbalancing that I wish I could have use Avalon for.
They are generic enought that can find their way into
a framework. The questions deal with failover only
though.

This is a message orient application.  To properly
fail-over I would have one instance that is servicing
requests. Upon failure, the stand-by server(s) would
detect failure, negotiate its status to come up as the
primary server amongst possibly other servers and
start servicing request by picking up where the other
applicaiton left off.   Naturaly this carries many
implications some of which are:
- how to negotiate being primary server? rating
system?
- how to know where to "pick up"? does this mean
sharing  application state? does this mean sharing
user session state? 
- if sharing state, using central state/session
repository(possibly slow, single point of failure) or
publishing state/session to all other servers
periodically.
- what to use as the communication protocol amongst
servers? socket, jmx(openJMX implementation eg).



> > I can forsee hot stand-by situation needed where
> one
> > instance of application (with all of its
> components)
> > upon failure would fail over to another running
> > instance of Phonenix.    Or the high load on one
> > application can be balanced across multiple
> running
> > Avalon/Phoneix instances with proper sharing of
> > session information for seamless
> > load-balance/fail-over.
> 
> The problems is defining "load" - given that it is
> relatively impossible to 
> define generically we would need to define some
> mechanism for application to 
> expose this and fail conditions. And then another
> monitor application detects 
> these status and reacts as appropriate. We already
> have support for this via 
> JMX but no one has really gone deep into that level
> of control yet.
> 
> -- 
> Cheers,
> 
> Peter Donald
> --------------------------------------------
>  Beer is proof that God loves us and wants 
>  us to be happy. -- Benjamin Franklin
> -------------------------------------------- 
> 
> 
>
---------------------------------------------------------------------
> To unsubscribe, e-mail:
> [EMAIL PROTECTED]
> For additional commands, e-mail:
> [EMAIL PROTECTED]
> 


__________________________________________________
Do you Yahoo!?
Yahoo! Platinum - Watch CBS' NCAA March Madness, live on your desktop!
http://platinum.yahoo.com

---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]

Reply via email to