Mention session affinity in docs

docs/gitbook/how-it-works.md

@@ -331,6 +331,7 @@ promotes it without analysing it. If an analysis is underway, Flagger cancels it
 
 Besides weighted routing, Flagger can be configured to route traffic to the canary based on HTTP match conditions.
 In an A/B testing scenario, you'll be using HTTP headers or cookies to target a certain segment of your users.
+This is particularly useful for frontend applications that require session affinity.
 
 Spec:
 

pkg/controller/deployer.go

@@ -220,7 +220,7 @@ func (c *CanaryDeployer) SetStatusWeight(cd *flaggerv1.Canary, val int) error {
 	return nil
 }
 
-// SetStatusWeight updates the canary status weight value
+// SetStatusIterations updates the canary status iterations value
 func (c *CanaryDeployer) SetStatusIterations(cd *flaggerv1.Canary, val int) error {
 	cdCopy := cd.DeepCopy()
 	cdCopy.Status.Iterations = val

pkg/controller/scheduler.go

@@ -471,13 +471,6 @@ func (c *Controller) hasCanaryRevisionChanged(cd *flaggerv1.Canary) bool {
 	return false
 }
 
-func (c *Controller) hasMaxIterations(cd *flaggerv1.Canary) bool {
-	if cd.Status.Iterations == cd.Status.Iterations {
-		return true
-	}
-	return false
-}
-
 func (c *Controller) analyseCanary(r *flaggerv1.Canary) bool {
 	// run external checks
 	for _, webhook := range r.Spec.CanaryAnalysis.Webhooks {