Overload Manager (proto)
The Overload Manager provides an extensible framework to protect Envoy instances from overload of various resources (memory, cpu, file descriptors, etc). It monitors a configurable set of resources and notifies registered listeners when triggers related to those resources fire.
config.overload.v3.ResourceMonitor
[config.overload.v3.ResourceMonitor proto]
{
"name": ...,
"typed_config": {...}
}
- name
(string, REQUIRED) The name of the resource monitor to instantiate. Must match a registered resource monitor type. See the extensions listed in typed_config below for the default list of available resource monitor.
- typed_config
(Any) Configuration for the resource monitor being instantiated.
Tip
This extension category has the following known extensions:
config.overload.v3.ThresholdTrigger
[config.overload.v3.ThresholdTrigger proto]
{
"value": ...
}
- value
(double) If the resource pressure is greater than or equal to this value, the trigger will enter saturation.
config.overload.v3.ScaledTrigger
[config.overload.v3.ScaledTrigger proto]
{
"scaling_threshold": ...,
"saturation_threshold": ...
}
- scaling_threshold
(double) If the resource pressure is greater than this value, the trigger will be in the scaling state with value
(pressure - scaling_threshold) / (saturation_threshold - scaling_threshold).
- saturation_threshold
(double) If the resource pressure is greater than this value, the trigger will enter saturation.
config.overload.v3.Trigger
[config.overload.v3.Trigger proto]
{
"name": ...,
"threshold": {...},
"scaled": {...}
}
- name
(string, REQUIRED) The name of the resource this is a trigger for.
- threshold
- scaled
config.overload.v3.ScaleTimersOverloadActionConfig
[config.overload.v3.ScaleTimersOverloadActionConfig proto]
Typed configuration for the “envoy.overload_actions.reduce_timeouts” action. See the docs for an example of how to configure the action with different timeouts and minimum values.
{
"timer_scale_factors": []
}
- timer_scale_factors
(repeated config.overload.v3.ScaleTimersOverloadActionConfig.ScaleTimer, REQUIRED) A set of timer scaling rules to be applied.
config.overload.v3.ScaleTimersOverloadActionConfig.ScaleTimer
[config.overload.v3.ScaleTimersOverloadActionConfig.ScaleTimer proto]
{
"timer": ...,
"min_timeout": {...},
"min_scale": {...}
}
- timer
(config.overload.v3.ScaleTimersOverloadActionConfig.TimerType) The type of timer this minimum applies to.
- min_timeout
(Duration) Sets the minimum duration as an absolute value.
Precisely one of min_timeout, min_scale must be set.
- min_scale
(type.v3.Percent) Sets the minimum duration as a percentage of the maximum value.
Precisely one of min_timeout, min_scale must be set.
Enum config.overload.v3.ScaleTimersOverloadActionConfig.TimerType
[config.overload.v3.ScaleTimersOverloadActionConfig.TimerType proto]
- UNSPECIFIED
(DEFAULT) Unsupported value; users must explicitly specify the timer they want scaled.
- HTTP_DOWNSTREAM_CONNECTION_IDLE
Adjusts the idle timer for downstream HTTP connections that takes effect when there are no active streams. This affects the value of HttpConnectionManager.common_http_protocol_options.idle_timeout
- HTTP_DOWNSTREAM_STREAM_IDLE
Adjusts the idle timer for HTTP streams initiated by downstream clients. This affects the value of RouteAction.idle_timeout and HttpConnectionManager.stream_idle_timeout
- TRANSPORT_SOCKET_CONNECT
Adjusts the timer for how long downstream clients have to finish transport-level negotiations before the connection is closed. This affects the value of FilterChain.transport_socket_connect_timeout.
config.overload.v3.OverloadAction
[config.overload.v3.OverloadAction proto]
{
"name": ...,
"triggers": [],
"typed_config": {...}
}
- name
(string, REQUIRED) The name of the overload action. This is just a well-known string that listeners can use for registering callbacks. Custom overload actions should be named using reverse DNS to ensure uniqueness.
- triggers
(repeated config.overload.v3.Trigger, REQUIRED) A set of triggers for this action. The state of the action is the maximum state of all triggers, which can be scaling between 0 and 1 or saturated. Listeners are notified when the overload action changes state.
- typed_config
(Any) Configuration for the action being instantiated.
config.overload.v3.BufferFactoryConfig
[config.overload.v3.BufferFactoryConfig proto]
Configuration for which accounts the WatermarkBuffer Factories should track.
{
"minimum_account_to_track_power_of_two": ...
}
- minimum_account_to_track_power_of_two
(uint32) The minimum power of two at which Envoy starts tracking an account.
Envoy has 8 power of two buckets starting with the provided exponent below. Concretely the 1st bucket contains accounts for streams that use [2^minimum_account_to_track_power_of_two, 2^(minimum_account_to_track_power_of_two + 1)) bytes. With the 8th bucket tracking accounts >= 128 * 2^minimum_account_to_track_power_of_two.
The maximum value is 56, since we’re using uint64_t for bytes counting, and that’s the last value that would use the 8 buckets. In practice, we don’t expect the proxy to be holding 2^56 bytes.
If omitted, Envoy should not do any tracking.
config.overload.v3.OverloadManager
[config.overload.v3.OverloadManager proto]
{
"refresh_interval": {...},
"resource_monitors": [],
"actions": [],
"buffer_factory_config": {...}
}
- refresh_interval
(Duration) The interval for refreshing resource usage.
- resource_monitors
(repeated config.overload.v3.ResourceMonitor, REQUIRED) The set of resources to monitor.
- actions
(repeated config.overload.v3.OverloadAction) The set of overload actions.
- buffer_factory_config
(config.overload.v3.BufferFactoryConfig) Configuration for buffer factory.