the test user, we will notice that the v2 version of the <code>reviews</code> service has a bug. Note that all other users are unaware of this testing against the live system.</p></li><li><p><a href="/v0.3/docs/tasks/traffic-management/traffic-shifting.html">Traffic Shifting</a> Finally, we will use Istio to gradually migrate traffic for all users from to a v3 version of the <code>reviews</code> service, one which includes the fix for the bug discovered in v2.</p></li></ol><h2 id="cleanup">Cleanup</h2><p>Wh