package envoy.extensions.load_balancing_policies.load_aware_locality.v3
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load_aware_locality.proto:25Configuration for the load_aware_locality LB policy which uses ORCA utilization data to route traffic between localities based on available headroom. [#next-free-field: 10]
optional endpoint_picking_policy = 1
The child LB policy to create for endpoint-picking within each locality.
optional weight_update_period = 2
How frequently ORCA weights and locality utilization are recomputed on the main thread. Must be at least 100ms. Defaults to 1s.
repeated string metric_names_for_computing_utilization = 3
By default, endpoint utilization is computed based on the :ref:`application_utilization <envoy_v3_api_field_.xds.data.orca.v3.OrcaLoadReport.application_utilization>` field reported by the endpoint. If that field is not set, then utilization will instead be computed by taking the max of the values of the metrics specified here. For map fields in the ORCA proto, the string will be of the form ``<map_field_name>.<map_key>``. For example, the string ``named_metrics.foo`` will mean to look for the key ``foo`` in the ORCA :ref:`named_metrics <envoy_v3_api_field_.xds.data.orca.v3.OrcaLoadReport.named_metrics>` field. If none of the specified metrics are present in the load report, then :ref:`cpu_utilization <envoy_v3_api_field_.xds.data.orca.v3.OrcaLoadReport.cpu_utilization>` is used instead.
optional utilization_variance_threshold = 4
When the local locality's utilization is at most this threshold above the remote average, route 100% of traffic to the local locality. This avoids unnecessary cross-zone routing when utilization is roughly balanced. One-sided: if the local zone is less loaded than remote, all-local routing always applies. Must be in [0, 1]. Defaults to 0.1.
optional smoothing_time_constant = 5
EWMA time constant for per-locality utilization smoothing. The per-tick smoothing factor alpha is derived as ``1 - exp(-weight_update_period / smoothing_time_constant)``, so settling time is consistent regardless of the configured tick rate. Larger values produce more stable weights; smaller values react faster. Must be greater than 0s. Defaults to 5s (~95% settling within ~15s).
optional remote_probe_fraction = 6
Minimum fraction of traffic sent to non-local localities to keep ORCA data fresh when the local-preference check would otherwise route 100% of traffic to the local locality. The deficit is redistributed across remote localities proportionally to their host count. Must be in [0, 1). Set to 0 to disable (safe only when ORCA reports arrive out-of-band, or when cross-zone traffic must be strictly avoided). Defaults to 0.03 (3%). Probe fraction is a global value split across all remote localities. At very high remote-locality counts combined with low aggregate request rates, per-host sample intervals can exceed ``weight_expiration_period``. See the architecture overview for the scaling matrix.
optional weight_expiration_period = 7
Per-host ORCA sample validity window. Hosts that have not reported load metrics within this duration are excluded from their locality's utilization aggregation. The locality's EWMA state continues normally over the remaining reporting hosts. If every host in a locality is stale, the locality falls back to host-count-proportional weighting (the same path used when all localities are overloaded). Set to 0s to disable expiration. Defaults to 3 minutes.
optional enable_oob_load_report = 8
Whether to enable out-of-band utilization reporting collection from the endpoints. By default, per-request utilization reporting is used.
optional oob_reporting_period = 9
Load reporting interval to request from the server. Note that the server may not provide reports as frequently as the client requests. Used only when enable_oob_load_report is true. Default is 10 seconds.