A system’s application servers need to be patched. The requirements for maintenance work are as follows:
▪ System downtime is not allowed.
▪ The application server in use must be in the sane patch status.
▪ System performance must be maintained during patching work.
▪ Testing after patching must be done before the application server is in use.
▪ If any trouble occurs, recover the previous version in ten minutes.
Which of the following methodologies should be selected?
A. Rolling update
B. Patching directly
C. Blue-green deployment
D. Three staging environments
