grpc-go/xds/internal/balancer/outlierdetection/config.go

241 lines
10 KiB
Go

/*
*
* Copyright 2022 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package outlierdetection
import (
"encoding/json"
"time"
iserviceconfig "google.golang.org/grpc/internal/serviceconfig"
"google.golang.org/grpc/serviceconfig"
)
// SuccessRateEjection is parameters for the success rate ejection algorithm.
// This algorithm monitors the request success rate for all endpoints and ejects
// individual endpoints whose success rates are statistical outliers.
type SuccessRateEjection struct {
// StddevFactor is used to determine the ejection threshold for
// success rate outlier ejection. The ejection threshold is the difference
// between the mean success rate, and the product of this factor and the
// standard deviation of the mean success rate: mean - (stdev *
// success_rate_stdev_factor). This factor is divided by a thousand to get a
// double. That is, if the desired factor is 1.9, the runtime value should
// be 1900. Defaults to 1900.
StdevFactor uint32 `json:"stdevFactor,omitempty"`
// EnforcementPercentage is the % chance that a host will be actually ejected
// when an outlier status is detected through success rate statistics. This
// setting can be used to disable ejection or to ramp it up slowly. Defaults
// to 100.
EnforcementPercentage uint32 `json:"enforcementPercentage,omitempty"`
// MinimumHosts is the number of hosts in a cluster that must have enough
// request volume to detect success rate outliers. If the number of hosts is
// less than this setting, outlier detection via success rate statistics is
// not performed for any host in the cluster. Defaults to 5.
MinimumHosts uint32 `json:"minimumHosts,omitempty"`
// RequestVolume is the minimum number of total requests that must be
// collected in one interval (as defined by the interval duration above) to
// include this host in success rate based outlier detection. If the volume
// is lower than this setting, outlier detection via success rate statistics
// is not performed for that host. Defaults to 100.
RequestVolume uint32 `json:"requestVolume,omitempty"`
}
// For UnmarshalJSON to work correctly and set defaults without infinite
// recursion.
type successRateEjection SuccessRateEjection
// UnmarshalJSON unmarshals JSON into SuccessRateEjection. If a
// SuccessRateEjection field is not set, that field will get its default value.
func (sre *SuccessRateEjection) UnmarshalJSON(j []byte) error {
sre.StdevFactor = 1900
sre.EnforcementPercentage = 100
sre.MinimumHosts = 5
sre.RequestVolume = 100
// Unmarshal JSON on a type with zero values for methods, including
// UnmarshalJSON. Overwrites defaults, leaves alone if not. typecast to
// avoid infinite recursion by not recalling this function and causing stack
// overflow.
return json.Unmarshal(j, (*successRateEjection)(sre))
}
// Equal returns whether the SuccessRateEjection is the same with the parameter.
func (sre *SuccessRateEjection) Equal(sre2 *SuccessRateEjection) bool {
if sre == nil && sre2 == nil {
return true
}
if (sre != nil) != (sre2 != nil) {
return false
}
if sre.StdevFactor != sre2.StdevFactor {
return false
}
if sre.EnforcementPercentage != sre2.EnforcementPercentage {
return false
}
if sre.MinimumHosts != sre2.MinimumHosts {
return false
}
return sre.RequestVolume == sre2.RequestVolume
}
// FailurePercentageEjection is parameters for the failure percentage algorithm.
// This algorithm ejects individual endpoints whose failure rate is greater than
// some threshold, independently of any other endpoint.
type FailurePercentageEjection struct {
// Threshold is the failure percentage to use when determining failure
// percentage-based outlier detection. If the failure percentage of a given
// host is greater than or equal to this value, it will be ejected. Defaults
// to 85.
Threshold uint32 `json:"threshold,omitempty"`
// EnforcementPercentage is the % chance that a host will be actually
// ejected when an outlier status is detected through failure percentage
// statistics. This setting can be used to disable ejection or to ramp it up
// slowly. Defaults to 0.
EnforcementPercentage uint32 `json:"enforcementPercentage,omitempty"`
// MinimumHosts is the minimum number of hosts in a cluster in order to
// perform failure percentage-based ejection. If the total number of hosts
// in the cluster is less than this value, failure percentage-based ejection
// will not be performed. Defaults to 5.
MinimumHosts uint32 `json:"minimumHosts,omitempty"`
// RequestVolume is the minimum number of total requests that must be
// collected in one interval (as defined by the interval duration above) to
// perform failure percentage-based ejection for this host. If the volume is
// lower than this setting, failure percentage-based ejection will not be
// performed for this host. Defaults to 50.
RequestVolume uint32 `json:"requestVolume,omitempty"`
}
// For UnmarshalJSON to work correctly and set defaults without infinite
// recursion.
type failurePercentageEjection FailurePercentageEjection
// UnmarshalJSON unmarshals JSON into FailurePercentageEjection. If a
// FailurePercentageEjection field is not set, that field will get its default
// value.
func (fpe *FailurePercentageEjection) UnmarshalJSON(j []byte) error {
fpe.Threshold = 85
fpe.EnforcementPercentage = 0
fpe.MinimumHosts = 5
fpe.RequestVolume = 50
// Unmarshal JSON on a type with zero values for methods, including
// UnmarshalJSON. Overwrites defaults, leaves alone if not. typecast to
// avoid infinite recursion by not recalling this function and causing stack
// overflow.
return json.Unmarshal(j, (*failurePercentageEjection)(fpe))
}
// Equal returns whether the FailurePercentageEjection is the same with the
// parameter.
func (fpe *FailurePercentageEjection) Equal(fpe2 *FailurePercentageEjection) bool {
if fpe == nil && fpe2 == nil {
return true
}
if (fpe != nil) != (fpe2 != nil) {
return false
}
if fpe.Threshold != fpe2.Threshold {
return false
}
if fpe.EnforcementPercentage != fpe2.EnforcementPercentage {
return false
}
if fpe.MinimumHosts != fpe2.MinimumHosts {
return false
}
return fpe.RequestVolume == fpe2.RequestVolume
}
// LBConfig is the config for the outlier detection balancer.
type LBConfig struct {
serviceconfig.LoadBalancingConfig `json:"-"`
// Interval is the time interval between ejection analysis sweeps. This can
// result in both new ejections as well as addresses being returned to
// service. Defaults to 10s.
Interval iserviceconfig.Duration `json:"interval,omitempty"`
// BaseEjectionTime is the base time that a host is ejected for. The real
// time is equal to the base time multiplied by the number of times the host
// has been ejected and is capped by MaxEjectionTime. Defaults to 30s.
BaseEjectionTime iserviceconfig.Duration `json:"baseEjectionTime,omitempty"`
// MaxEjectionTime is the maximum time that an address is ejected for. If
// not specified, the default value (300s) or the BaseEjectionTime value is
// applied, whichever is larger.
MaxEjectionTime iserviceconfig.Duration `json:"maxEjectionTime,omitempty"`
// MaxEjectionPercent is the maximum % of an upstream cluster that can be
// ejected due to outlier detection. Defaults to 10% but will eject at least
// one host regardless of the value.
MaxEjectionPercent uint32 `json:"maxEjectionPercent,omitempty"`
// SuccessRateEjection is the parameters for the success rate ejection
// algorithm. If set, success rate ejections will be performed.
SuccessRateEjection *SuccessRateEjection `json:"successRateEjection,omitempty"`
// FailurePercentageEjection is the parameters for the failure percentage
// algorithm. If set, failure rate ejections will be performed.
FailurePercentageEjection *FailurePercentageEjection `json:"failurePercentageEjection,omitempty"`
// ChildPolicy is the config for the child policy.
ChildPolicy *iserviceconfig.BalancerConfig `json:"childPolicy,omitempty"`
}
// For UnmarshalJSON to work correctly and set defaults without infinite
// recursion.
type lbConfig LBConfig
// UnmarshalJSON unmarshals JSON into LBConfig. If a top level LBConfig field
// (i.e. not next layer sre or fpe) is not set, that field will get its default
// value. If sre or fpe is not set, it will stay unset, otherwise it will
// unmarshal on those types populating with default values for their fields if
// needed.
func (lbc *LBConfig) UnmarshalJSON(j []byte) error {
// Default top layer values as documented in A50.
lbc.Interval = iserviceconfig.Duration(10 * time.Second)
lbc.BaseEjectionTime = iserviceconfig.Duration(30 * time.Second)
lbc.MaxEjectionTime = iserviceconfig.Duration(300 * time.Second)
lbc.MaxEjectionPercent = 10
// Unmarshal JSON on a type with zero values for methods, including
// UnmarshalJSON. Overwrites defaults, leaves alone if not. typecast to
// avoid infinite recursion by not recalling this function and causing stack
// overflow.
return json.Unmarshal(j, (*lbConfig)(lbc))
}
// EqualIgnoringChildPolicy returns whether the LBConfig is same with the
// parameter outside of the child policy, only comparing the Outlier Detection
// specific configuration.
func (lbc *LBConfig) EqualIgnoringChildPolicy(lbc2 *LBConfig) bool {
if lbc == nil && lbc2 == nil {
return true
}
if (lbc != nil) != (lbc2 != nil) {
return false
}
if lbc.Interval != lbc2.Interval {
return false
}
if lbc.BaseEjectionTime != lbc2.BaseEjectionTime {
return false
}
if lbc.MaxEjectionTime != lbc2.MaxEjectionTime {
return false
}
if lbc.MaxEjectionPercent != lbc2.MaxEjectionPercent {
return false
}
if !lbc.SuccessRateEjection.Equal(lbc2.SuccessRateEjection) {
return false
}
return lbc.FailurePercentageEjection.Equal(lbc2.FailurePercentageEjection)
}