quotas

Documentation

Index

• func DynamicRateLimiterFactory(rps RPSKeyFunc) func(string) Limiter
• func PerMember(service string, globalRPS, instanceRPS float64, resolver membership.Resolver) float64
• type Collection
  • func NewCollection(factory func(string) Limiter) *Collection
  • func (c *Collection) For(key string) Limiter
• type DynamicRateLimiter
  • func NewDynamicRateLimiter(rps RPSFunc) *DynamicRateLimiter
  • func (d *DynamicRateLimiter) Allow() bool
  • func (d *DynamicRateLimiter) Reserve() *rate.Reservation
  • func (d *DynamicRateLimiter) Wait(ctx context.Context) error
• type Info
• type Limiter
• type MultiStageRateLimiter
  • func NewMultiStageRateLimiter(global Limiter, domainLimiters *Collection) *MultiStageRateLimiter
  • func (d *MultiStageRateLimiter) Allow(info Info) bool
• type Policy
• type RPSFunc
  • func PerMemberDynamic(service string, globalRPS, instanceRPS RPSFunc, resolver membership.Resolver) RPSFunc
• type RPSKeyFunc
• type RateLimiter
  • func NewRateLimiter(maxDispatchPerSecond *float64, ttl time.Duration, minBurst int) *RateLimiter
  • func NewSimpleRateLimiter(rps int) *RateLimiter
  • func (rl *RateLimiter) Allow() bool
  • func (rl *RateLimiter) Limit() float64
  • func (rl *RateLimiter) Reserve() *rate.Reservation
  • func (rl *RateLimiter) UpdateMaxDispatch(maxDispatchPerSecond *float64)
  • func (rl *RateLimiter) Wait(ctx context.Context) error

Functions

func DynamicRateLimiterFactory

func DynamicRateLimiterFactory(rps RPSKeyFunc) func(string) Limiter

DynamicRateLimiterFactory creates a factory function for creating DynamicRateLimiters

func PerMember

func PerMember(service string, globalRPS, instanceRPS float64, resolver membership.Resolver) float64

PerMember allows creating per instance RPS based on globalRPS averaged by member count for a given service. If member count can not be retrieved or globalRPS is not provided it falls back to instanceRPS.

Types

type Collection

type Collection struct {
	// contains filtered or unexported fields
}

Collection stores a map of limiters by key

func NewCollection

func NewCollection(factory func(string) Limiter) *Collection

NewCollection create a new limiter collection. Given factory is called to create new individual limiter.

func (*Collection) For

func (c *Collection) For(key string) Limiter

For retrieves limiter by a given key. If limiter for such key does not exists, it creates new one with via factory.

type DynamicRateLimiter

type DynamicRateLimiter struct {
	// contains filtered or unexported fields
}

DynamicRateLimiter implements a dynamic config wrapper around the rate limiter

func NewDynamicRateLimiter

func NewDynamicRateLimiter(rps RPSFunc) *DynamicRateLimiter

NewDynamicRateLimiter returns a rate limiter which handles dynamic config

func (*DynamicRateLimiter) Allow

func (d *DynamicRateLimiter) Allow() bool

Allow immediately returns with true or false indicating if a rate limit token is available or not

func (*DynamicRateLimiter) Reserve

func (d *DynamicRateLimiter) Reserve() *rate.Reservation

Reserve reserves a rate limit token

func (*DynamicRateLimiter) Wait

func (d *DynamicRateLimiter) Wait(ctx context.Context) error

Wait waits up till deadline for a rate limit token

type Info

type Info struct {
	Domain string
}

Info corresponds to information required to determine rate limits

type Limiter

type Limiter interface {
	// Allow attempts to allow a request to go through. The method returns
	// immediately with a true or false indicating if the request can make
	// progress
	Allow() bool

	// Wait waits till the deadline for a rate limit token to allow the request
	// to go through.
	Wait(ctx context.Context) error

	// Reserve reserves a rate limit token
	Reserve() *rate.Reservation
}

Limiter corresponds to basic rate limiting functionality.

type MultiStageRateLimiter

type MultiStageRateLimiter struct {
	// contains filtered or unexported fields
}

MultiStageRateLimiter indicates a domain specific rate limit policy

func NewMultiStageRateLimiter

func NewMultiStageRateLimiter(global Limiter, domainLimiters *Collection) *MultiStageRateLimiter

NewMultiStageRateLimiter returns a new domain quota rate limiter. This is about an order of magnitude slower than

func (*MultiStageRateLimiter) Allow

func (d *MultiStageRateLimiter) Allow(info Info) bool

Allow attempts to allow a request to go through. The method returns immediately with a true or false indicating if the request can make progress

type Policy

type Policy interface {
	// Allow attempts to allow a request to go through. The method returns
	// immediately with a true or false indicating if the request can make
	// progress
	Allow(info Info) bool
}

Policy corresponds to a quota policy. A policy allows implementing layered and more complex rate limiting functionality.

type RPSFunc

type RPSFunc func() float64

RPSFunc returns a float64 as the RPS

func PerMemberDynamic

func PerMemberDynamic(service string, globalRPS, instanceRPS RPSFunc, resolver membership.Resolver) RPSFunc

PerMemberDynamic is a dynamic variant (using RPSFunc) of PerMember

type RPSKeyFunc

type RPSKeyFunc func(key string) float64

RPSKeyFunc returns a float64 as the RPS for the given key

type RateLimiter

type RateLimiter struct {
	sync.RWMutex
	// contains filtered or unexported fields
}

RateLimiter is a wrapper around the golang rate limiter handling dynamic configuration updates of the max dispatch per second. This has comparable performance to the token bucket rate limiter. BenchmarkSimpleRateLimiter-4 10000000 114 ns/op (tokenbucket) BenchmarkRateLimiter-4 10000000 148 ns/op (this)

func NewRateLimiter

func NewRateLimiter(maxDispatchPerSecond *float64, ttl time.Duration, minBurst int) *RateLimiter

NewRateLimiter returns a new rate limiter that can handle dynamic configuration updates

func NewSimpleRateLimiter

func NewSimpleRateLimiter(rps int) *RateLimiter

NewSimpleRateLimiter returns a new rate limiter backed by the golang rate limiter

func (*RateLimiter) Allow

func (rl *RateLimiter) Allow() bool

Allow immediately returns with true or false indicating if a rate limit token is available or not

func (*RateLimiter) Limit

func (rl *RateLimiter) Limit() float64

Limit returns the current rate per second limit for this ratelimiter

func (*RateLimiter) Reserve

func (rl *RateLimiter) Reserve() *rate.Reservation

Reserve reserves a rate limit token

func (*RateLimiter) UpdateMaxDispatch

func (rl *RateLimiter) UpdateMaxDispatch(maxDispatchPerSecond *float64)

UpdateMaxDispatch updates the max dispatch rate of the rate limiter

func (*RateLimiter) Wait

func (rl *RateLimiter) Wait(ctx context.Context) error

Wait waits up till deadline for a rate limit token