When one Intelligence server node in the cluster crashes, Strategy Web issues calls to get the latest cluster membership:
Before each web session/login request, web would call the API to get the cluster membership.
The load balancer is a component that exists inside the Strategy Web Server product: even when there is only one web server, that component is there. The Strategy load balancer component would be able to calculate and balance based on the loads for nodes in the cluster membership
Refer to Technical Document below for clustering architecture of Strategy:
KB16018: MicroStrategy Intelligence Server Clustering FAQ
Article reference: KB46152