Load balancing requirements for clustering CAS 3.0.x+

[Mike Kennedy]

Andrew,

In our setup we use JBoss which uses Tomcat 5.5 as its embedded servlet
container. I don't use an Apache/AJP front end at all.

I set up a virtual host on each of the nodes of the cluster that
corresponds to the hostname associated with the ip on the frontend load
balancer.

In JBoss I added a jboss-web.xml file to the WEB-INF directory of the
cas web application that specifies which virtual host to deploy into.
With a standalone Tomcat installation like you want you can specify a
directory as part of of the <Host></Host> virtual host definition in
server.xml and deploy cas.war there.

Once that was set up I simply followed the instructions in this document
to finish the installation:

http://www.ja-sig.org/wiki/display/CASUM/Clustering+CAS

In this document there are three important things that need to be done:
guarantee ticket uniqueness, tomcat session replication and cas ticket
cache replication.

With my clustered JBoss setup I got tomcat session replication straight
out of the box with JBossCache/JGroups. So all I needed to worry about
were the spring bean configuration changes for ticket uniqueness and CAS
ticket replication backed by the JBossCache.

Mike

On Tue, 2007-08-07 at 13:00 -0500, Andrew R Feller wrote:
> Thanks for the response Mike!
> 
> My main concern stems from the issue with the cookies created by the CAS
> servers.  They appear to be set for the domain of the server that issued
> it (e.g. casA.example.com, casB.example.com, etc), which won't be
> available to the other servers in the cluster.
> 
> How are the CAS servers in your cluster set up?  I take it you have a
> single URL, which directs requests to a server.  What additional steps
> must be done to configure Apache/Tomcat/CAS for load balancing outside
> of a normal CAS deployment?
> 
> Thanks,
> 
> Andrew R Feller, Analyst
> Subversion Administrator
> University Information Systems
> Louisiana State University
> afelle1 at lsu.edu
> (office) 225.578.3737
> 
> -----Original Message-----
> From: cas-bounces at tp.its.yale.edu [mailto:cas-bounces at tp.its.yale.edu]
> On Behalf Of Mike Kennedy
> Sent: Tuesday, August 07, 2007 11:33 AM
> To: Yale CAS mailing list
> Subject: Re: Load balancing requirements for clustering CAS 3.0.x+
> 
> At our site we have CAS clustering working with an F5 load balancer
> using sticky sessions. However, if the load balancer detects that a node
> fails it migrates those sessions to another node where the Tomcat
> session and ticket cache have already been replicated.
> 
> In other words, we use sticky sessions and have uninterrupted service
> within the cluster.
> 
> On Tue, 2007-08-07 at 11:05 -0500, Andrew R Feller wrote:
> > Q: Are there any load balancing requirements for clustering CAS 3
> > server?
> > 
> >  
> > 
> > While following the Clustering CAS walkthrough in the CAS wiki, I
> > notice it didn't go in-depth about what options are available.  Aside
> > from using sticky sessions to redirect the user back to the CAS server
> > they were authenticated against, what other options are available?  I
> > would prefer not to use sticky sessions as we want uninterrupted
> > service within the cluster.
> > 
> >  
> > 
> > Thanks,
> > 
> >  
> > 
> > Andrew R Feller, Analyst
> > 
> > Subversion Administrator
> > 
> > University Information Systems
> > 
> > Louisiana State University
> > 
> > afelle1 at lsu.edu
> > 
> > (office) 225.578.3737
> > 
> >  
> > 
> > 
> > _______________________________________________
> > Yale CAS mailing list
> > cas at tp.its.yale.edu
> > http://tp.its.yale.edu/mailman/listinfo/cas
-- 
Mike Kennedy
Lead Technologist for Research Computing
Infrastructure and Security Group
mikek at ucr.edu
951.827.4875