(Soft Rollout requires HTTP Load Balancing, which is only
available in OctaGate Switch Enterprise Edition)
Soft Rollout / Graceful Web Application Upgrade
When you run a web application, deploying a new version typically means that you need to stop the old
web application to deploy the new one. All connected users will
lose their sessions, causing frustration.
Perhaps even worse, for the duration of the deployment cycle
(shut down, install, start up) the web service will be completely offline).
OctaGate Switch can help you avoid this!
You can upgrade your web application several times in one day, and users won't notice, because their sessions will continue to work!
Phasing Out an Old Server - Phasing In a New Server
When OctaGate Switch runs Load Balancing on a domain, it keeps track of users and
what server they have been connected to before. We call this a
session is persistent over time, so that a user will keep connecting to the
same server for the duration of the session.
When you want to phase out one server, you simply set that servers "capacity"
value to zero, which means that it will not be handed any new connections, but
old connections will remain valid!
To update a web application, you start the new web application on a different
port or a different server. Then you add a new Load
Balanced Server to the Load Balancing Cluster that handles the Web Application.
Then you set the Capacity of the old server to zero and the capacity of the new
server to a non-zero value. Voila, the new server will receive all new
There is a tutorial
that describe in detail how to create a server cluster.
Works on Cluster With Multiple Servers
If your web application is handled, through Load Balancing, by several
servers, you can easily perform this operation on each of the servers. Thus you
can perform a graceful update from one application version to another for a very
large web site!