Struct Policy

pub struct Policy {
    pub drop_overloads: Vec<DropOverload>,
    pub overprovisioning_factor: Option<UInt32Value>,
    pub endpoint_stale_after: Option<Duration>,
    pub weighted_priority_health: bool,
}

Load balancing policy settings. [#next-free-field: 7]

Fields

drop_overloads: Vec<DropOverload>

Action to trim the overall incoming traffic to protect the upstream hosts. This action allows protection in case the hosts are unable to recover from an outage, or unable to autoscale or unable to handle incoming traffic volume for any reason.

At the client each category is applied one after the other to generate the ‘actual’ drop percentage on all outgoing traffic. For example:

.. code-block:: json

{ “drop_overloads”: [ { “category”: “throttle”, “drop_percentage”: 60 } { “category”: “lb”, “drop_percentage”: 50 } ]}

The actual drop percentages applied to the traffic at the clients will be “throttle”_drop = 60% “lb”_drop = 20% // 50% of the remaining ‘actual’ load, which is 40%. actual_outgoing_load = 20% // remaining after applying all categories.

Envoy supports only one element and will NACK if more than one element is present. Other xDS-capable data planes will not necessarily have this limitation.

In Envoy, this drop_overloads config can be overridden by a runtime key “load_balancing_policy.drop_overload_limit” setting. This runtime key can be set to any integer number between 0 and 100. 0 means drop 0%. 100 means drop 100%. When both drop_overloads config and “load_balancing_policy.drop_overload_limit” setting are in place, the min of these two wins.

overprovisioning_factor: Option<UInt32Value>

Priority levels and localities are considered overprovisioned with this factor (in percentage). This means that we don’t consider a priority level or locality unhealthy until the fraction of healthy hosts multiplied by the overprovisioning factor drops below 100. With the default value 140(1.4), Envoy doesn’t consider a priority level or a locality unhealthy until their percentage of healthy hosts drops below 72%. For example:

.. code-block:: json

{ “overprovisioning_factor”: 100 }

Read more at :ref:priority levels <arch_overview_load_balancing_priority_levels> and :ref:localities <arch_overview_load_balancing_locality_weighted_lb>.

endpoint_stale_after: Option<Duration>

The max time until which the endpoints from this assignment can be used. If no new assignments are received before this time expires the endpoints are considered stale and should be marked unhealthy. Defaults to 0 which means endpoints never go stale.

weighted_priority_health: bool

If true, use the :ref:load balancing weight <envoy_v3_api_field_config.endpoint.v3.LbEndpoint.load_balancing_weight> of healthy and unhealthy hosts to determine the health of the priority level. If false, use the number of healthy and unhealthy hosts to determine the health of the priority level, or in other words assume each host has a weight of 1 for this calculation.

Note: this is not currently implemented for :ref:locality weighted load balancing <arch_overview_load_balancing_locality_weighted_lb>.

Trait Implementations

impl Clone for Policy

fn clone(&self) -> Policy

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Policy

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Policy

fn default() -> Self

Returns the “default value” for a type.

impl Message for Policy

fn encoded_len(&self) -> usize

Returns the encoded length of the message without a length delimiter.

fn clear(&mut self)

Clears the message, resetting all fields to their default.

fn encode(&self, buf: &mut impl BufMut) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message to a buffer.

fn encode_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message to a newly allocated buffer.

fn encode_length_delimited( &self, buf: &mut impl BufMut, ) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message with a length-delimiter to a buffer.

fn encode_length_delimited_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message with a length-delimiter to a newly allocated buffer.

fn decode(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes an instance of the message from a buffer.

fn decode_length_delimited(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes a length-delimited instance of the message from the buffer.

fn merge(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes an instance of the message from a buffer, and merges it into self.

fn merge_length_delimited(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes a length-delimited instance of the message from buffer, and merges it into self.

impl Name for Policy

const NAME: &'static str = "Policy"

Simple name for this Message. This name is the same as it appears in the source .proto file, e.g. FooBar.

const PACKAGE: &'static str = "envoy.config.endpoint.v3"

Package name this message type is contained in. They are domain-like and delimited by ., e.g. google.protobuf.

fn full_name() -> String

Fully-qualified unique name for this Message. It’s prefixed with the package name and names of any parent messages, e.g. google.rpc.BadRequest.FieldViolation. By default, this is the package name followed by the message name. Fully-qualified names must be unique within a domain of Type URLs.

fn type_url() -> String

Type URL for this Message, which by default is the full name with a leading slash, but may also include a leading domain name, e.g. type.googleapis.com/google.profile.Person. This can be used when serializing into the google.protobuf.Any type.

impl PartialEq for Policy

fn eq(&self, other: &Policy) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Policy