CF 7 cluster does not respond to configuration changes

Question

I am evaluating the clustering capabilities of CF 7 in order
to upgrade our current CF6 + ClusterCats cluster.
I installed CF7 (enterprise edition – multiserver) in
two physical servers (Win 2003). On each server I created one
instance of CF and successfully registered the remote instance on
each server. Then, I configured the cluster on the first server,
selecting the weighted random algorithm for load balance and
session replication. Then, I used the webserver configuration tool
to bind the cluster to each IIS server.
The cluster worked properly, balancing the load between the
two cf instances, but when trying to find a way to temporally
restrict the load on one server for maintenance purposes I found
that the cluster does not respond to cluster configuration changes.
I changed the load to 0-100% using the coldfusion administrator
interface but it did not work. The cluster still sends requests to
the “restricted” instance. I even eliminated that
instance from the list of instances that integrates the cluster,
but it did not affect the behavior of the cluster. The eliminated
instance still serves request from the cluster. I even eliminated
the remote instance register and nothing… the cluster still
balancing the load between the two instances that originally
integrated the cluster.
I do not understand how this is supposed to work. Does the
cluster configuration interface works only when creating the
cluster? When the changes in the cluster configuration performed
from the CF admin interface should be reflected by the behavior of
the cluster? What is the recommended procedure to temporally
restrict one instance from the cluster without stopping the
service?
I appreciate your help
Eduardo

Answer 1

Thanks for the information Jochem. I am afraid that these are
not good news. If I have to restart the webserver in order to
change the load balance, some requests in progress could be lost.
My current configuration is composed by two physical severs,
each one running a web server and a coldfusion instance. We balance
the load between both webservers using hardware load balancing.
This is the procedure that I have to follow in order restrict one
instance without loosing any request:
1.- Change server weight using Coldfusion admin interface
2.- Configure hardware load balance to restrict server 1
3.- Restart webserver at server 1
4.- Configure hardware load balance to enable server 1 and
restrict server 2
5.- Restart webserver at server 2
6.- Configure hardware load balance to enable server 2
A similar procedure should be followed in order to enable the
restricted instance. I know that I can do it for 2 servers; but,
how is it handled in larger clusters? Is there a better procedure
to restrict one instance without missing requests?
Eduardo