High Availability - Web Deployment
The Server does not implement clustering, to simplify the deployment; instead multiple production servers would sit in parallel in a server farm. Web browser access occurs through a sticky load balancer, forwarding traffic to the appropriate Server.
Typically there is a staging Server that is tested against, before published workbooks are deployed to the production Server instances on the server farm. This deployment can be manual or scripted.
Additional environments may exist (e.g., development, test, disaster recovery)
For true high availability the data sources that are being accessed by the production server instances should also be highly available/clustered.