Which algorithm Kubernetes uses to nevigate traffics in replicaset/deployment

kubernetes replicaset kubernetes-deployment

The algorithm applied to determine which pod will process the request depends on kube-proxy mode that is running.

In 1.0, the proxy works in mode called userspace and default algorithm is round robin.
In 1.2 mode iptables proxy was added, but still round robin is used due to iptables limitations.
In 1.8.0-beta, IP Virtual Server (IPVS) was introduced, it allow much more algorithms options, like:
- RoundRobin;
- WeightedRoundRobin;
- LeastConnection;
- WeightedLeastConnection;
- LocalityBasedLeastConnection;
- LocalityBasedLeastConnectionWithReplication;
- SourceHashing;
- DestinationHashing;
- ShortestExpectedDelay;
- NeverQueue.

References:

CodeHunter