Ejemplo n.º 1
0
func TestTokenBucketLimiter(t *testing.T) {
	e := func(context.Context, interface{}) (interface{}, error) { return struct{}{}, nil }
	for _, n := range []int{1, 2, 100} {
		tb := jujuratelimit.NewBucketWithRate(float64(n), int64(n))
		testLimiter(t, ratelimit.NewTokenBucketLimiter(tb)(e), n)
	}
}
Ejemplo n.º 2
0
func main() {
	logger := log.NewLogfmtLogger(os.Stdout)

	ctx := context.Background()

	c := &countService{}

	var svc endpoint.Endpoint
	svc = makeAddEndpoint(c)

	limit := ratelimit.NewBucket(2*time.Second, 1)
	svc = kitratelimit.NewTokenBucketLimiter(limit)(svc)

	requestCount := expvar.NewCounter("request.count")
	svc = metricsMiddleware(requestCount)(svc)
	svc = loggingMiddlware(logger)(svc)

	addHandler := httptransport.NewServer(
		ctx,
		svc,
		decodeAddRequest,
		encodeResponse,
		httptransport.ServerBefore(beforeIDExtractor, beforePATHExtractor),
	)

	http.Handle("/add", addHandler)

	port := os.Getenv("PORT")
	logger.Log("listening on", port)
	if err := http.ListenAndServe(":"+port, nil); err != nil {
		logger.Log("listen.error", err)
	}
}
Ejemplo n.º 3
0
func factory(ctx context.Context, qps int) loadbalancer.Factory {
	return func(instance string) (endpoint.Endpoint, io.Closer, error) {
		var e endpoint.Endpoint
		e = makeUppercaseProxy(ctx, instance)
		e = circuitbreaker.Gobreaker(gobreaker.NewCircuitBreaker(gobreaker.Settings{}))(e)
		e = kitratelimit.NewTokenBucketLimiter(jujuratelimit.NewBucketWithRate(float64(qps), int64(qps)))(e)
		return e, nil, nil
	}
}
Ejemplo n.º 4
0
func TestTokenBucketLimiter(t *testing.T) {
	e := func(context.Context, interface{}) (interface{}, error) { return struct{}{}, nil }
	for _, n := range []int{1, 2, 100} {
		testLimiter(t, ratelimit.NewTokenBucketLimiter(
			ratelimit.TokenBucketLimiterRate(float64(n)),
			ratelimit.TokenBucketLimiterCapacity(int64(n)),
		)(e), int(n))
	}
}
Ejemplo n.º 5
0
// New returns an AddService backed by an HTTP server living at the remote
// instance. We expect instance to come from a service discovery system, so
// likely of the form "host:port".
func New(instance string, tracer stdopentracing.Tracer, logger log.Logger) (addsvc.Service, error) {
	if !strings.HasPrefix(instance, "http") {
		instance = "http://" + instance
	}
	u, err := url.Parse(instance)
	if err != nil {
		return nil, err
	}

	// We construct a single ratelimiter middleware, to limit the total outgoing
	// QPS from this client to all methods on the remote instance. We also
	// construct per-endpoint circuitbreaker middlewares to demonstrate how
	// that's done, although they could easily be combined into a single breaker
	// for the entire remote instance, too.

	limiter := ratelimit.NewTokenBucketLimiter(jujuratelimit.NewBucketWithRate(100, 100))

	var sumEndpoint endpoint.Endpoint
	{
		sumEndpoint = httptransport.NewClient(
			"POST",
			copyURL(u, "/sum"),
			addsvc.EncodeHTTPGenericRequest,
			addsvc.DecodeHTTPSumResponse,
			httptransport.SetClientBefore(opentracing.FromHTTPRequest(tracer, "Sum", logger)),
		).Endpoint()
		sumEndpoint = opentracing.TraceClient(tracer, "Sum")(sumEndpoint)
		sumEndpoint = limiter(sumEndpoint)
		sumEndpoint = circuitbreaker.Gobreaker(gobreaker.NewCircuitBreaker(gobreaker.Settings{
			Name:    "Sum",
			Timeout: 30 * time.Second,
		}))(sumEndpoint)
	}

	var concatEndpoint endpoint.Endpoint
	{
		concatEndpoint = httptransport.NewClient(
			"POST",
			copyURL(u, "/concat"),
			addsvc.EncodeHTTPGenericRequest,
			addsvc.DecodeHTTPConcatResponse,
			httptransport.SetClientBefore(opentracing.FromHTTPRequest(tracer, "Concat", logger)),
		).Endpoint()
		concatEndpoint = opentracing.TraceClient(tracer, "Concat")(concatEndpoint)
		concatEndpoint = limiter(concatEndpoint)
		sumEndpoint = circuitbreaker.Gobreaker(gobreaker.NewCircuitBreaker(gobreaker.Settings{
			Name:    "Concat",
			Timeout: 30 * time.Second,
		}))(sumEndpoint)
	}

	return addsvc.Endpoints{
		SumEndpoint:    sumEndpoint,
		ConcatEndpoint: concatEndpoint,
	}, nil
}
Ejemplo n.º 6
0
Archivo: client.go Proyecto: crezam/kit
// New returns an AddService backed by a gRPC client connection. It is the
// responsibility of the caller to dial, and later close, the connection.
func New(conn *grpc.ClientConn, tracer stdopentracing.Tracer, logger log.Logger) addsvc.Service {
	// We construct a single ratelimiter middleware, to limit the total outgoing
	// QPS from this client to all methods on the remote instance. We also
	// construct per-endpoint circuitbreaker middlewares to demonstrate how
	// that's done, although they could easily be combined into a single breaker
	// for the entire remote instance, too.

	limiter := ratelimit.NewTokenBucketLimiter(jujuratelimit.NewBucketWithRate(100, 100))

	var sumEndpoint endpoint.Endpoint
	{
		sumEndpoint = grpctransport.NewClient(
			conn,
			"Add",
			"Sum",
			addsvc.EncodeGRPCSumRequest,
			addsvc.DecodeGRPCSumResponse,
			pb.SumReply{},
			grpctransport.ClientBefore(opentracing.FromGRPCRequest(tracer, "Sum", logger)),
		).Endpoint()
		sumEndpoint = opentracing.TraceClient(tracer, "Sum")(sumEndpoint)
		sumEndpoint = limiter(sumEndpoint)
		sumEndpoint = circuitbreaker.Gobreaker(gobreaker.NewCircuitBreaker(gobreaker.Settings{
			Name:    "Sum",
			Timeout: 30 * time.Second,
		}))(sumEndpoint)
	}

	var concatEndpoint endpoint.Endpoint
	{
		concatEndpoint = grpctransport.NewClient(
			conn,
			"Add",
			"Concat",
			addsvc.EncodeGRPCConcatRequest,
			addsvc.DecodeGRPCConcatResponse,
			pb.ConcatReply{},
			grpctransport.ClientBefore(opentracing.FromGRPCRequest(tracer, "Concat", logger)),
		).Endpoint()
		concatEndpoint = opentracing.TraceClient(tracer, "Concat")(concatEndpoint)
		concatEndpoint = limiter(concatEndpoint)
		concatEndpoint = circuitbreaker.Gobreaker(gobreaker.NewCircuitBreaker(gobreaker.Settings{
			Name:    "Concat",
			Timeout: 30 * time.Second,
		}))(concatEndpoint)
	}

	return addsvc.Endpoints{
		SumEndpoint:    sumEndpoint,
		ConcatEndpoint: concatEndpoint,
	}
}
Ejemplo n.º 7
0
func proxyingMiddleware(instances string, ctx context.Context, logger log.Logger) ServiceMiddleware {
	// If instances is empty, don't proxy.
	if instances == "" {
		logger.Log("proxy_to", "none")
		return func(next StringService) StringService { return next }
	}

	// Set some parameters for our client.
	var (
		qps         = 100                    // beyond which we will return an error
		maxAttempts = 3                      // per request, before giving up
		maxTime     = 250 * time.Millisecond // wallclock time, before giving up
	)

	// Otherwise, construct an endpoint for each instance in the list, and add
	// it to a fixed set of endpoints. In a real service, rather than doing this
	// by hand, you'd probably use package sd's support for your service
	// discovery system.
	var (
		instanceList = split(instances)
		subscriber   sd.FixedSubscriber
	)
	logger.Log("proxy_to", fmt.Sprint(instanceList))
	for _, instance := range instanceList {
		var e endpoint.Endpoint
		e = makeUppercaseProxy(ctx, instance)
		e = circuitbreaker.Gobreaker(gobreaker.NewCircuitBreaker(gobreaker.Settings{}))(e)
		e = ratelimit.NewTokenBucketLimiter(jujuratelimit.NewBucketWithRate(float64(qps), int64(qps)))(e)
		subscriber = append(subscriber, e)
	}

	// Now, build a single, retrying, load-balancing endpoint out of all of
	// those individual endpoints.
	balancer := lb.NewRoundRobin(subscriber)
	retry := lb.Retry(maxAttempts, maxTime, balancer)

	// And finally, return the ServiceMiddleware, implemented by proxymw.
	return func(next StringService) StringService {
		return proxymw{ctx, next, retry}
	}
}
Ejemplo n.º 8
0
// New returns an AddService backed by a Thrift server described by the provided
// client. The caller is responsible for constructing the client, and eventually
// closing the underlying transport.
func New(client *thriftadd.AddServiceClient) addsvc.Service {
	// We construct a single ratelimiter middleware, to limit the total outgoing
	// QPS from this client to all methods on the remote instance. We also
	// construct per-endpoint circuitbreaker middlewares to demonstrate how
	// that's done, although they could easily be combined into a single breaker
	// for the entire remote instance, too.

	limiter := ratelimit.NewTokenBucketLimiter(jujuratelimit.NewBucketWithRate(100, 100))

	// Thrift does not currently have tracer bindings, so we skip tracing.

	var sumEndpoint endpoint.Endpoint
	{
		sumEndpoint = addsvc.MakeThriftSumEndpoint(client)
		sumEndpoint = limiter(sumEndpoint)
		sumEndpoint = circuitbreaker.Gobreaker(gobreaker.NewCircuitBreaker(gobreaker.Settings{
			Name:    "Sum",
			Timeout: 30 * time.Second,
		}))(sumEndpoint)
	}

	var concatEndpoint endpoint.Endpoint
	{
		concatEndpoint = addsvc.MakeThriftConcatEndpoint(client)
		concatEndpoint = limiter(concatEndpoint)
		sumEndpoint = circuitbreaker.Gobreaker(gobreaker.NewCircuitBreaker(gobreaker.Settings{
			Name:    "Concat",
			Timeout: 30 * time.Second,
		}))(sumEndpoint)
	}

	return addsvc.Endpoints{
		SumEndpoint:    addsvc.MakeThriftSumEndpoint(client),
		ConcatEndpoint: addsvc.MakeThriftConcatEndpoint(client),
	}
}