Request routing This task will first direct all incoming traffic for the Bookinfo application to the v1 version of the reviews service. It will then send traffic only from a specific test user to version v2, leaving all other users unaffected.
Fault injection We will now use Istio to test the resiliency of the Bookinfo application by injecting an artificial delay in requests between the reviews:v2 and ratings services. Observing the resulting behavior as the test user, we will notice that the v2 version of the reviews service has a bug. Note that all other users are unaware of this testing against the live system.
Traffic Shifting Finally, we will use Istio to gradually migrate traffic for all users from to a v3 version of the reviews service, one which includes the fix for the bug discovered in v2.