Shiny 1.1.0: Scaling Shiny with async

This is a companion discussion topic for the original entry at https://www.rstudio.com/blog/shiny-1-1-0


This is a significant release for Shiny, with a major new feature that was nearly a year in the making: support for asynchronous operations!
Without this capability, when Shiny performs long-running calculations or tasks on behalf of one user, it stalls progress for all other Shiny users that are connected to the same process. Therefore, Shiny apps that feature long-running calculations or tasks have generally been deployed using many R processes, each serving a small number of users; this works, but is not the most efficient approach.