istio

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