proxy

Documentation

Index

• Variables
• func Handler(breaker *Breaker, next http.Handler) http.HandlerFunc
• func NewReverseProxy(target string, maxIdle, maxIdlePerHost int) *httputil.ReverseProxy
• type Breaker
  • func NewBreaker(params BreakerParams) *Breaker
  • func (b *Breaker) Capacity() int
  • func (b *Breaker) InFlight() int64
  • func (b *Breaker) Maybe(ctx context.Context, thunk func()) error
  • func (b *Breaker) QueueLength() int64
  • func (b *Breaker) Reserve(_ context.Context) (func(), bool)
  • func (b *Breaker) UpdateConcurrency(size int)
  • func (b *Breaker) UpdateQueueLength(size int)
• type BreakerParams
• type PrometheusStatsReporter
  • func NewPrometheusStatsReporter() *PrometheusStatsReporter
  • func (r *PrometheusStatsReporter) Report(stats RequestStatsReport)
  • func (r *PrometheusStatsReporter) ServeHTTP(w http.ResponseWriter, req *http.Request)
• type RequestStats
  • func (s *RequestStats) Append(val int64)
  • func (s *RequestStats) GetAllAndDelete() []int64
  • func (s *RequestStats) Report() RequestStatsReport
• type RequestStatsReport

Variables

var (
	// ErrRequestQueueFull indicates the breaker queue depth was exceeded.
	ErrRequestQueueFull = errors.New("pending request queue full")
)

Functions

func Handler

func Handler(breaker *Breaker, next http.Handler) http.HandlerFunc

func NewReverseProxy

func NewReverseProxy(target string, maxIdle, maxIdlePerHost int) *httputil.ReverseProxy

NewReverseProxy creates a new cortex base reverse proxy

Types

type Breaker

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

Breaker is a component that enforces a concurrency limit on the execution of a function. It also maintains a queue of function executions in excess of the concurrency limit. Function call attempts beyond the limit of the queue are failed immediately.

func NewBreaker

func NewBreaker(params BreakerParams) *Breaker

NewBreaker creates a Breaker with the desired queue depth, concurrency limit and initial capacity.

func (*Breaker) Capacity

func (b *Breaker) Capacity() int

Capacity returns the number of allowed in-flight requests on this breaker.

func (*Breaker) InFlight

func (b *Breaker) InFlight() int64

InFlight returns the number of requests currently in flight in this breaker.

func (*Breaker) Maybe

func (b *Breaker) Maybe(ctx context.Context, thunk func()) error

Maybe conditionally executes thunk based on the Breaker concurrency and queue parameters. If the concurrency limit and queue capacity are already consumed, Maybe returns immediately without calling thunk. If the thunk was executed, Maybe returns true, else false.

func (*Breaker) QueueLength

func (b *Breaker) QueueLength() int64

func (*Breaker) Reserve

func (b *Breaker) Reserve(_ context.Context) (func(), bool)

Reserve reserves an execution slot in the breaker, to permit richer semantics in the caller. The caller on success must execute the callback when done with work.

func (*Breaker) UpdateConcurrency

func (b *Breaker) UpdateConcurrency(size int)

UpdateConcurrency updates the maximum number of in-flight requests.

func (*Breaker) UpdateQueueLength

func (b *Breaker) UpdateQueueLength(size int)

UpdateQueueLength updates the number of allowed requests in-queue

type BreakerParams

type BreakerParams struct {
	QueueDepth      int
	MaxConcurrency  int
	InitialCapacity int
}

BreakerParams defines the parameters of the breaker.

type PrometheusStatsReporter

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

func NewPrometheusStatsReporter

func NewPrometheusStatsReporter() *PrometheusStatsReporter

func (*PrometheusStatsReporter) Report

func (r *PrometheusStatsReporter) Report(stats RequestStatsReport)

func (*PrometheusStatsReporter) ServeHTTP

func (r *PrometheusStatsReporter) ServeHTTP(w http.ResponseWriter, req *http.Request)

type RequestStats

type RequestStats struct {
	sync.Mutex
	// contains filtered or unexported fields
}

func (*RequestStats) Append

func (s *RequestStats) Append(val int64)

func (*RequestStats) GetAllAndDelete

func (s *RequestStats) GetAllAndDelete() []int64

func (*RequestStats) Report

func (s *RequestStats) Report() RequestStatsReport

type RequestStatsReport

type RequestStatsReport struct {
	AvgInFlight float64
}