In load balancing how sticky sessions work with origin weight?


I am testing Load Balancer for a traffic migration use case. We are migrating our workloads from one cluster to another cluster. During the migration we will have maintenance time. Our plan is to create a 3 origins as follows

  • Current cluster
  • Maintenance Page
  • New cluster

The migration flow(based on origin weight) will be:

  1. Current Cluster(100%), Maintenance Page(0%), New cluster(0%)
  2. Current Cluster(0%), Maintenance Page(100%), New cluster(0%)
  3. Current Cluster(0%), Maintenance Page(90%), New cluster(10%)
    continues like this and…
    N. Current Cluster(0%), Maintenance Page(0%), New cluster(100%)

We will be enabling session affinity. My question is how session affinity work with origin weight. For example at #2 100% traffic will be in maintenance page & 0% on New cluster and session affinity enabled, in that I assume all clients will be set with cflib cookie. When 10% traffic move to New Cluster how it works for the clients already cflib cookie present ?

Thank in Advance!