When the Pega Platform server that fails is taken out of service from the load balancer, requests that were serviced from the crashed server are redirected to new Pega Platform servers. This implies that a production class load balancer is employed, as well as passive or active monitoring of the application.

There are two steps in recovery:

• On redirection to a new Pega Platform server, the user must re-authenticate. The high availability best practice is to enable single sign-on to avoid user interruption.
• When the server processes the request, it detects that there has been a crash event and uses the user interface metadata to reconstruct the user interface. Since the user’s clipboard is not preserved from the crash, data that has been entered but not committed on assign, perform, and confirm harnesses is lost.