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Diffstat (limited to 'vendor/github.com/uber/jaeger-client-go/sampler.go')
| -rw-r--r-- | vendor/github.com/uber/jaeger-client-go/sampler.go | 516 |
1 files changed, 0 insertions, 516 deletions
diff --git a/vendor/github.com/uber/jaeger-client-go/sampler.go b/vendor/github.com/uber/jaeger-client-go/sampler.go deleted file mode 100644 index d0be8ad50..000000000 --- a/vendor/github.com/uber/jaeger-client-go/sampler.go +++ /dev/null @@ -1,516 +0,0 @@ -// Copyright (c) 2017 Uber Technologies, Inc. -// -// 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 jaeger - -import ( - "fmt" - "math" - "strings" - "sync" - - "github.com/uber/jaeger-client-go/thrift-gen/sampling" - "github.com/uber/jaeger-client-go/utils" -) - -const ( - defaultMaxOperations = 2000 -) - -// Sampler decides whether a new trace should be sampled or not. -type Sampler interface { - // IsSampled decides whether a trace with given `id` and `operation` - // should be sampled. This function will also return the tags that - // can be used to identify the type of sampling that was applied to - // the root span. Most simple samplers would return two tags, - // sampler.type and sampler.param, similar to those used in the Configuration - IsSampled(id TraceID, operation string) (sampled bool, tags []Tag) - - // Close does a clean shutdown of the sampler, stopping any background - // go-routines it may have started. - Close() - - // Equal checks if the `other` sampler is functionally equivalent - // to this sampler. - // TODO (breaking change) remove this function. See PerOperationSampler.Equals for explanation. - Equal(other Sampler) bool -} - -// ----------------------- - -// ConstSampler is a sampler that always makes the same decision. -type ConstSampler struct { - legacySamplerV1Base - Decision bool - tags []Tag -} - -// NewConstSampler creates a ConstSampler. -func NewConstSampler(sample bool) *ConstSampler { - tags := []Tag{ - {key: SamplerTypeTagKey, value: SamplerTypeConst}, - {key: SamplerParamTagKey, value: sample}, - } - s := &ConstSampler{ - Decision: sample, - tags: tags, - } - s.delegate = s.IsSampled - return s -} - -// IsSampled implements IsSampled() of Sampler. -func (s *ConstSampler) IsSampled(id TraceID, operation string) (bool, []Tag) { - return s.Decision, s.tags -} - -// Close implements Close() of Sampler. -func (s *ConstSampler) Close() { - // nothing to do -} - -// Equal implements Equal() of Sampler. -func (s *ConstSampler) Equal(other Sampler) bool { - if o, ok := other.(*ConstSampler); ok { - return s.Decision == o.Decision - } - return false -} - -// String is used to log sampler details. -func (s *ConstSampler) String() string { - return fmt.Sprintf("ConstSampler(decision=%t)", s.Decision) -} - -// ----------------------- - -// ProbabilisticSampler is a sampler that randomly samples a certain percentage -// of traces. -type ProbabilisticSampler struct { - legacySamplerV1Base - samplingRate float64 - samplingBoundary uint64 - tags []Tag -} - -const maxRandomNumber = ^(uint64(1) << 63) // i.e. 0x7fffffffffffffff - -// NewProbabilisticSampler creates a sampler that randomly samples a certain percentage of traces specified by the -// samplingRate, in the range between 0.0 and 1.0. -// -// It relies on the fact that new trace IDs are 63bit random numbers themselves, thus making the sampling decision -// without generating a new random number, but simply calculating if traceID < (samplingRate * 2^63). -// TODO remove the error from this function for next major release -func NewProbabilisticSampler(samplingRate float64) (*ProbabilisticSampler, error) { - if samplingRate < 0.0 || samplingRate > 1.0 { - return nil, fmt.Errorf("Sampling Rate must be between 0.0 and 1.0, received %f", samplingRate) - } - return newProbabilisticSampler(samplingRate), nil -} - -func newProbabilisticSampler(samplingRate float64) *ProbabilisticSampler { - s := new(ProbabilisticSampler) - s.delegate = s.IsSampled - return s.init(samplingRate) -} - -func (s *ProbabilisticSampler) init(samplingRate float64) *ProbabilisticSampler { - s.samplingRate = math.Max(0.0, math.Min(samplingRate, 1.0)) - s.samplingBoundary = uint64(float64(maxRandomNumber) * s.samplingRate) - s.tags = []Tag{ - {key: SamplerTypeTagKey, value: SamplerTypeProbabilistic}, - {key: SamplerParamTagKey, value: s.samplingRate}, - } - return s -} - -// SamplingRate returns the sampling probability this sampled was constructed with. -func (s *ProbabilisticSampler) SamplingRate() float64 { - return s.samplingRate -} - -// IsSampled implements IsSampled() of Sampler. -func (s *ProbabilisticSampler) IsSampled(id TraceID, operation string) (bool, []Tag) { - return s.samplingBoundary >= id.Low&maxRandomNumber, s.tags -} - -// Close implements Close() of Sampler. -func (s *ProbabilisticSampler) Close() { - // nothing to do -} - -// Equal implements Equal() of Sampler. -func (s *ProbabilisticSampler) Equal(other Sampler) bool { - if o, ok := other.(*ProbabilisticSampler); ok { - return s.samplingBoundary == o.samplingBoundary - } - return false -} - -// Update modifies in-place the sampling rate. Locking must be done externally. -func (s *ProbabilisticSampler) Update(samplingRate float64) error { - if samplingRate < 0.0 || samplingRate > 1.0 { - return fmt.Errorf("Sampling Rate must be between 0.0 and 1.0, received %f", samplingRate) - } - s.init(samplingRate) - return nil -} - -// String is used to log sampler details. -func (s *ProbabilisticSampler) String() string { - return fmt.Sprintf("ProbabilisticSampler(samplingRate=%v)", s.samplingRate) -} - -// ----------------------- - -// RateLimitingSampler samples at most maxTracesPerSecond. The distribution of sampled traces follows -// burstiness of the service, i.e. a service with uniformly distributed requests will have those -// requests sampled uniformly as well, but if requests are bursty, especially sub-second, then a -// number of sequential requests can be sampled each second. -type RateLimitingSampler struct { - legacySamplerV1Base - maxTracesPerSecond float64 - rateLimiter *utils.ReconfigurableRateLimiter - tags []Tag -} - -// NewRateLimitingSampler creates new RateLimitingSampler. -func NewRateLimitingSampler(maxTracesPerSecond float64) *RateLimitingSampler { - s := new(RateLimitingSampler) - s.delegate = s.IsSampled - return s.init(maxTracesPerSecond) -} - -func (s *RateLimitingSampler) init(maxTracesPerSecond float64) *RateLimitingSampler { - if s.rateLimiter == nil { - s.rateLimiter = utils.NewRateLimiter(maxTracesPerSecond, math.Max(maxTracesPerSecond, 1.0)) - } else { - s.rateLimiter.Update(maxTracesPerSecond, math.Max(maxTracesPerSecond, 1.0)) - } - s.maxTracesPerSecond = maxTracesPerSecond - s.tags = []Tag{ - {key: SamplerTypeTagKey, value: SamplerTypeRateLimiting}, - {key: SamplerParamTagKey, value: maxTracesPerSecond}, - } - return s -} - -// IsSampled implements IsSampled() of Sampler. -func (s *RateLimitingSampler) IsSampled(id TraceID, operation string) (bool, []Tag) { - return s.rateLimiter.CheckCredit(1.0), s.tags -} - -// Update reconfigures the rate limiter, while preserving its accumulated balance. -// Locking must be done externally. -func (s *RateLimitingSampler) Update(maxTracesPerSecond float64) { - if s.maxTracesPerSecond != maxTracesPerSecond { - s.init(maxTracesPerSecond) - } -} - -// Close does nothing. -func (s *RateLimitingSampler) Close() { - // nothing to do -} - -// Equal compares with another sampler. -func (s *RateLimitingSampler) Equal(other Sampler) bool { - if o, ok := other.(*RateLimitingSampler); ok { - return s.maxTracesPerSecond == o.maxTracesPerSecond - } - return false -} - -// String is used to log sampler details. -func (s *RateLimitingSampler) String() string { - return fmt.Sprintf("RateLimitingSampler(maxTracesPerSecond=%v)", s.maxTracesPerSecond) -} - -// ----------------------- - -// GuaranteedThroughputProbabilisticSampler is a sampler that leverages both ProbabilisticSampler and -// RateLimitingSampler. The RateLimitingSampler is used as a guaranteed lower bound sampler such that -// every operation is sampled at least once in a time interval defined by the lowerBound. ie a lowerBound -// of 1.0 / (60 * 10) will sample an operation at least once every 10 minutes. -// -// The ProbabilisticSampler is given higher priority when tags are emitted, ie. if IsSampled() for both -// samplers return true, the tags for ProbabilisticSampler will be used. -type GuaranteedThroughputProbabilisticSampler struct { - probabilisticSampler *ProbabilisticSampler - lowerBoundSampler *RateLimitingSampler - tags []Tag - samplingRate float64 - lowerBound float64 -} - -// NewGuaranteedThroughputProbabilisticSampler returns a delegating sampler that applies both -// ProbabilisticSampler and RateLimitingSampler. -func NewGuaranteedThroughputProbabilisticSampler( - lowerBound, samplingRate float64, -) (*GuaranteedThroughputProbabilisticSampler, error) { - return newGuaranteedThroughputProbabilisticSampler(lowerBound, samplingRate), nil -} - -func newGuaranteedThroughputProbabilisticSampler(lowerBound, samplingRate float64) *GuaranteedThroughputProbabilisticSampler { - s := &GuaranteedThroughputProbabilisticSampler{ - lowerBoundSampler: NewRateLimitingSampler(lowerBound), - lowerBound: lowerBound, - } - s.setProbabilisticSampler(samplingRate) - return s -} - -func (s *GuaranteedThroughputProbabilisticSampler) setProbabilisticSampler(samplingRate float64) { - if s.probabilisticSampler == nil { - s.probabilisticSampler = newProbabilisticSampler(samplingRate) - } else if s.samplingRate != samplingRate { - s.probabilisticSampler.init(samplingRate) - } - // since we don't validate samplingRate, sampler may have clamped it to [0, 1] interval - samplingRate = s.probabilisticSampler.SamplingRate() - if s.samplingRate != samplingRate || s.tags == nil { - s.samplingRate = s.probabilisticSampler.SamplingRate() - s.tags = []Tag{ - {key: SamplerTypeTagKey, value: SamplerTypeLowerBound}, - {key: SamplerParamTagKey, value: s.samplingRate}, - } - } -} - -// IsSampled implements IsSampled() of Sampler. -func (s *GuaranteedThroughputProbabilisticSampler) IsSampled(id TraceID, operation string) (bool, []Tag) { - if sampled, tags := s.probabilisticSampler.IsSampled(id, operation); sampled { - s.lowerBoundSampler.IsSampled(id, operation) - return true, tags - } - sampled, _ := s.lowerBoundSampler.IsSampled(id, operation) - return sampled, s.tags -} - -// Close implements Close() of Sampler. -func (s *GuaranteedThroughputProbabilisticSampler) Close() { - s.probabilisticSampler.Close() - s.lowerBoundSampler.Close() -} - -// Equal implements Equal() of Sampler. -func (s *GuaranteedThroughputProbabilisticSampler) Equal(other Sampler) bool { - // NB The Equal() function is expensive and will be removed. See PerOperationSampler.Equal() for - // more information. - return false -} - -// this function should only be called while holding a Write lock -func (s *GuaranteedThroughputProbabilisticSampler) update(lowerBound, samplingRate float64) { - s.setProbabilisticSampler(samplingRate) - if s.lowerBound != lowerBound { - s.lowerBoundSampler.Update(lowerBound) - s.lowerBound = lowerBound - } -} - -func (s GuaranteedThroughputProbabilisticSampler) String() string { - return fmt.Sprintf("GuaranteedThroughputProbabilisticSampler(lowerBound=%f, samplingRate=%f)", s.lowerBound, s.samplingRate) -} - -// ----------------------- - -// PerOperationSampler is a delegating sampler that applies GuaranteedThroughputProbabilisticSampler -// on a per-operation basis. -type PerOperationSampler struct { - sync.RWMutex - - samplers map[string]*GuaranteedThroughputProbabilisticSampler - defaultSampler *ProbabilisticSampler - lowerBound float64 - maxOperations int - - // see description in PerOperationSamplerParams - operationNameLateBinding bool -} - -// NewAdaptiveSampler returns a new PerOperationSampler. -// Deprecated: please use NewPerOperationSampler. -func NewAdaptiveSampler(strategies *sampling.PerOperationSamplingStrategies, maxOperations int) (*PerOperationSampler, error) { - return NewPerOperationSampler(PerOperationSamplerParams{ - MaxOperations: maxOperations, - Strategies: strategies, - }), nil -} - -// PerOperationSamplerParams defines parameters when creating PerOperationSampler. -type PerOperationSamplerParams struct { - // Max number of operations that will be tracked. Other operations will be given default strategy. - MaxOperations int - - // Opt-in feature for applications that require late binding of span name via explicit call to SetOperationName. - // When this feature is enabled, the sampler will return retryable=true from OnCreateSpan(), thus leaving - // the sampling decision as non-final (and the span as writeable). This may lead to degraded performance - // in applications that always provide the correct span name on trace creation. - // - // For backwards compatibility this option is off by default. - OperationNameLateBinding bool - - // Initial configuration of the sampling strategies (usually retrieved from the backend by Remote Sampler). - Strategies *sampling.PerOperationSamplingStrategies -} - -// NewPerOperationSampler returns a new PerOperationSampler. -func NewPerOperationSampler(params PerOperationSamplerParams) *PerOperationSampler { - if params.MaxOperations <= 0 { - params.MaxOperations = defaultMaxOperations - } - samplers := make(map[string]*GuaranteedThroughputProbabilisticSampler) - for _, strategy := range params.Strategies.PerOperationStrategies { - sampler := newGuaranteedThroughputProbabilisticSampler( - params.Strategies.DefaultLowerBoundTracesPerSecond, - strategy.ProbabilisticSampling.SamplingRate, - ) - samplers[strategy.Operation] = sampler - } - return &PerOperationSampler{ - samplers: samplers, - defaultSampler: newProbabilisticSampler(params.Strategies.DefaultSamplingProbability), - lowerBound: params.Strategies.DefaultLowerBoundTracesPerSecond, - maxOperations: params.MaxOperations, - operationNameLateBinding: params.OperationNameLateBinding, - } -} - -// IsSampled is not used and only exists to match Sampler V1 API. -// TODO (breaking change) remove when upgrading everything to SamplerV2 -func (s *PerOperationSampler) IsSampled(id TraceID, operation string) (bool, []Tag) { - return false, nil -} - -func (s *PerOperationSampler) trySampling(span *Span, operationName string) (bool, []Tag) { - samplerV1 := s.getSamplerForOperation(operationName) - var sampled bool - var tags []Tag - if span.context.samplingState.isLocalRootSpan(span.context.spanID) { - sampled, tags = samplerV1.IsSampled(span.context.TraceID(), operationName) - } - return sampled, tags -} - -// OnCreateSpan implements OnCreateSpan of SamplerV2. -func (s *PerOperationSampler) OnCreateSpan(span *Span) SamplingDecision { - sampled, tags := s.trySampling(span, span.OperationName()) - return SamplingDecision{Sample: sampled, Retryable: s.operationNameLateBinding, Tags: tags} -} - -// OnSetOperationName implements OnSetOperationName of SamplerV2. -func (s *PerOperationSampler) OnSetOperationName(span *Span, operationName string) SamplingDecision { - sampled, tags := s.trySampling(span, operationName) - return SamplingDecision{Sample: sampled, Retryable: false, Tags: tags} -} - -// OnSetTag implements OnSetTag of SamplerV2. -func (s *PerOperationSampler) OnSetTag(span *Span, key string, value interface{}) SamplingDecision { - return SamplingDecision{Sample: false, Retryable: true} -} - -// OnFinishSpan implements OnFinishSpan of SamplerV2. -func (s *PerOperationSampler) OnFinishSpan(span *Span) SamplingDecision { - return SamplingDecision{Sample: false, Retryable: true} -} - -func (s *PerOperationSampler) getSamplerForOperation(operation string) Sampler { - s.RLock() - sampler, ok := s.samplers[operation] - if ok { - defer s.RUnlock() - return sampler - } - s.RUnlock() - s.Lock() - defer s.Unlock() - - // Check if sampler has already been created - sampler, ok = s.samplers[operation] - if ok { - return sampler - } - // Store only up to maxOperations of unique ops. - if len(s.samplers) >= s.maxOperations { - return s.defaultSampler - } - newSampler := newGuaranteedThroughputProbabilisticSampler(s.lowerBound, s.defaultSampler.SamplingRate()) - s.samplers[operation] = newSampler - return newSampler -} - -// Close invokes Close on all underlying samplers. -func (s *PerOperationSampler) Close() { - s.Lock() - defer s.Unlock() - for _, sampler := range s.samplers { - sampler.Close() - } - s.defaultSampler.Close() -} - -func (s *PerOperationSampler) String() string { - var sb strings.Builder - - fmt.Fprintf(&sb, "PerOperationSampler(defaultSampler=%v, ", s.defaultSampler) - fmt.Fprintf(&sb, "lowerBound=%f, ", s.lowerBound) - fmt.Fprintf(&sb, "maxOperations=%d, ", s.maxOperations) - fmt.Fprintf(&sb, "operationNameLateBinding=%t, ", s.operationNameLateBinding) - fmt.Fprintf(&sb, "numOperations=%d,\n", len(s.samplers)) - fmt.Fprintf(&sb, "samplers=[") - for operationName, sampler := range s.samplers { - fmt.Fprintf(&sb, "\n(operationName=%s, sampler=%v)", operationName, sampler) - } - fmt.Fprintf(&sb, "])") - - return sb.String() -} - -// Equal is not used. -// TODO (breaking change) remove this in the future -func (s *PerOperationSampler) Equal(other Sampler) bool { - // NB The Equal() function is overly expensive for PerOperationSampler since it's composed of multiple - // samplers which all need to be initialized before this function can be called for a comparison. - // Therefore, PerOperationSampler uses the update() function to only alter the samplers that need - // changing. Hence this function always returns false so that the update function can be called. - // Once the Equal() function is removed from the Sampler API, this will no longer be needed. - return false -} - -func (s *PerOperationSampler) update(strategies *sampling.PerOperationSamplingStrategies) { - s.Lock() - defer s.Unlock() - newSamplers := map[string]*GuaranteedThroughputProbabilisticSampler{} - for _, strategy := range strategies.PerOperationStrategies { - operation := strategy.Operation - samplingRate := strategy.ProbabilisticSampling.SamplingRate - lowerBound := strategies.DefaultLowerBoundTracesPerSecond - if sampler, ok := s.samplers[operation]; ok { - sampler.update(lowerBound, samplingRate) - newSamplers[operation] = sampler - } else { - sampler := newGuaranteedThroughputProbabilisticSampler( - lowerBound, - samplingRate, - ) - newSamplers[operation] = sampler - } - } - s.lowerBound = strategies.DefaultLowerBoundTracesPerSecond - if s.defaultSampler.SamplingRate() != strategies.DefaultSamplingProbability { - s.defaultSampler = newProbabilisticSampler(strategies.DefaultSamplingProbability) - } - s.samplers = newSamplers -} |