Directed Load Balancing with Sticky Sessions

[Mike Duffy <md...@yahoo.com>]

I've read through the load balancing info in the docs:  Using Apache HTTP Server 2.x with mod_proxy

What I would like to do is have users sign in on one server and then, based on geographic characteristics, redirect them to another server.

If I simply use the method sendRedirect(String location) from HttpServletResponse will the redirected users have a sticky sessions on the server I am redirecting them to?

We have a large base of geographically dispersed users.  Our data base is a far greater bottleneck than our application servers.  Our plan is to geographically segment the data base and then match a Tomcat server to a data base.

Any suggestions?

Thx.

Mike



      

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Re: Directed Load Balancing with Sticky Sessions

[Rainer Jung <ra...@kippdata.de>]

On 21.04.2009 07:48, Mike Duffy wrote:
> I've read through the load balancing info in the docs:  Using Apache
> HTTP Server 2.x with mod_proxy
> 
> What I would like to do is have users sign in on one server and then,
> based on geographic characteristics, redirect them to another
> server.
> 
> If I simply use the method sendRedirect(String location) from
> HttpServletResponse will the redirected users have a sticky sessions
> on the server I am redirecting them to?
> 
> We have a large base of geographically dispersed users.  Our data
> base is a far greater bottleneck than our application servers.  Our
> plan is to geographically segment the data base and then match a
> Tomcat server to a data base.
> 
> Any suggestions?

Geographic balancing via redirects will only work, if the different
locations use different server *names*. Otherwise any redirect URL will
point to the same server name, and since the client already resolved the
address, the request will be send to the same server IP. Geo-based
redirects can be done e.g. with Apache using GeoIP. They have a free geo
database. The commercial one is a bit better, but the free one is not to
bad.

If you need to use the same server name for all locations, you need to
make the geographic balancing in the DNS layer.

The third possibility is, that you only want to geographically
distribute the Tomcat layer and not the Apache layer. This is not very
likely, because then you will of course need a very good global internal
network between the Apaches and the distributed Tomcats. If you have
reasons for this concept, you could do this again with GeoIP and either
mod_proxy or mod_jk.

Regards,

Rainer

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