istio.io/istio@v0.0.0-20240520182934-d79c90f27776/releasenotes/notes/new_lb_algorithm_default.yaml (about)

     1  apiVersion: release-notes/v2
     2  kind: feature
     3  area: traffic-management
     4  
     5  releaseNotes:
     6    - |
     7      **Updated** Istio's default load balancing algorithm from `ROUND_ROBIN` to `LEAST_REQUEST`.
     8      The `ROUND_ROBIN` algorithm can lead to overburdened endpoints, especially when weights
     9      are used. The `LEAST_REQUEST` algorithm, distributes more evenly across and is far less
    10      likely to overburden endpoints. A number of experiments (by both the Istio and
    11      Envoy teams) have shown that `LEAST_REQUEST` outperforms `ROUND_ROBIN` in virtually all
    12      cases, with little/no downsides. It's generally considered a drop-in replacement for
    13      ROUND_ROBIN.
    14      
    15      `ROUND_ROBIN` will continue to be supported if explicitly specified. To restore
    16      `ROUND_ROBIN` as the default, set the istiod environment variable
    17      `ENABLE_LEGACY_LB_ALGORITHM_DEFAULT=true`.