[VOL-3071] Extended Log framework to accept Context as log method argument
and extract operation details from same based on Jaeger Tracing Span API.
Change-Id: Id0139ef94bc838c11d2b155353c51e5810db443f
diff --git a/vendor/github.com/uber/jaeger-client-go/sampler_remote.go b/vendor/github.com/uber/jaeger-client-go/sampler_remote.go
new file mode 100644
index 0000000..112e3e1
--- /dev/null
+++ b/vendor/github.com/uber/jaeger-client-go/sampler_remote.go
@@ -0,0 +1,337 @@
+// 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 (
+ "encoding/json"
+ "fmt"
+ "io/ioutil"
+ "net/http"
+ "net/url"
+ "sync"
+ "sync/atomic"
+ "time"
+
+ "github.com/uber/jaeger-client-go/log"
+ "github.com/uber/jaeger-client-go/thrift-gen/sampling"
+)
+
+const (
+ defaultSamplingRefreshInterval = time.Minute
+)
+
+// SamplingStrategyFetcher is used to fetch sampling strategy updates from remote server.
+type SamplingStrategyFetcher interface {
+ Fetch(service string) ([]byte, error)
+}
+
+// SamplingStrategyParser is used to parse sampling strategy updates. The output object
+// should be of the type that is recognized by the SamplerUpdaters.
+type SamplingStrategyParser interface {
+ Parse(response []byte) (interface{}, error)
+}
+
+// SamplerUpdater is used by RemotelyControlledSampler to apply sampling strategies,
+// retrieved from remote config server, to the current sampler. The updater can modify
+// the sampler in-place if sampler supports it, or create a new one.
+//
+// If the strategy does not contain configuration for the sampler in question,
+// updater must return modifiedSampler=nil to give other updaters a chance to inspect
+// the sampling strategy response.
+//
+// RemotelyControlledSampler invokes the updaters while holding a lock on the main sampler.
+type SamplerUpdater interface {
+ Update(sampler SamplerV2, strategy interface{}) (modified SamplerV2, err error)
+}
+
+// RemotelyControlledSampler is a delegating sampler that polls a remote server
+// for the appropriate sampling strategy, constructs a corresponding sampler and
+// delegates to it for sampling decisions.
+type RemotelyControlledSampler struct {
+ // These fields must be first in the struct because `sync/atomic` expects 64-bit alignment.
+ // Cf. https://github.com/uber/jaeger-client-go/issues/155, https://goo.gl/zW7dgq
+ closed int64 // 0 - not closed, 1 - closed
+
+ sync.RWMutex
+ samplerOptions
+
+ serviceName string
+ doneChan chan *sync.WaitGroup
+}
+
+// NewRemotelyControlledSampler creates a sampler that periodically pulls
+// the sampling strategy from an HTTP sampling server (e.g. jaeger-agent).
+func NewRemotelyControlledSampler(
+ serviceName string,
+ opts ...SamplerOption,
+) *RemotelyControlledSampler {
+ options := new(samplerOptions).applyOptionsAndDefaults(opts...)
+ sampler := &RemotelyControlledSampler{
+ samplerOptions: *options,
+ serviceName: serviceName,
+ doneChan: make(chan *sync.WaitGroup),
+ }
+ go sampler.pollController()
+ return sampler
+}
+
+// IsSampled implements IsSampled() of Sampler.
+// TODO (breaking change) remove when Sampler V1 is removed
+func (s *RemotelyControlledSampler) IsSampled(id TraceID, operation string) (bool, []Tag) {
+ return false, nil
+}
+
+// OnCreateSpan implements OnCreateSpan of SamplerV2.
+func (s *RemotelyControlledSampler) OnCreateSpan(span *Span) SamplingDecision {
+ return s.sampler.OnCreateSpan(span)
+}
+
+// OnSetOperationName implements OnSetOperationName of SamplerV2.
+func (s *RemotelyControlledSampler) OnSetOperationName(span *Span, operationName string) SamplingDecision {
+ return s.sampler.OnSetOperationName(span, operationName)
+}
+
+// OnSetTag implements OnSetTag of SamplerV2.
+func (s *RemotelyControlledSampler) OnSetTag(span *Span, key string, value interface{}) SamplingDecision {
+ return s.sampler.OnSetTag(span, key, value)
+}
+
+// OnFinishSpan implements OnFinishSpan of SamplerV2.
+func (s *RemotelyControlledSampler) OnFinishSpan(span *Span) SamplingDecision {
+ return s.sampler.OnFinishSpan(span)
+}
+
+// Close implements Close() of Sampler.
+func (s *RemotelyControlledSampler) Close() {
+ if swapped := atomic.CompareAndSwapInt64(&s.closed, 0, 1); !swapped {
+ s.logger.Error("Repeated attempt to close the sampler is ignored")
+ return
+ }
+
+ var wg sync.WaitGroup
+ wg.Add(1)
+ s.doneChan <- &wg
+ wg.Wait()
+}
+
+// Equal implements Equal() of Sampler.
+func (s *RemotelyControlledSampler) Equal(other Sampler) bool {
+ // NB The Equal() function is expensive and will be removed. See PerOperationSampler.Equal() for
+ // more information.
+ return false
+}
+
+func (s *RemotelyControlledSampler) pollController() {
+ ticker := time.NewTicker(s.samplingRefreshInterval)
+ defer ticker.Stop()
+ s.pollControllerWithTicker(ticker)
+}
+
+func (s *RemotelyControlledSampler) pollControllerWithTicker(ticker *time.Ticker) {
+ for {
+ select {
+ case <-ticker.C:
+ s.UpdateSampler()
+ case wg := <-s.doneChan:
+ wg.Done()
+ return
+ }
+ }
+}
+
+// Sampler returns the currently active sampler.
+func (s *RemotelyControlledSampler) Sampler() SamplerV2 {
+ s.Lock()
+ defer s.Unlock()
+ return s.sampler
+}
+
+func (s *RemotelyControlledSampler) setSampler(sampler SamplerV2) {
+ s.Lock()
+ defer s.Unlock()
+ s.sampler = sampler
+}
+
+// UpdateSampler forces the sampler to fetch sampling strategy from backend server.
+// This function is called automatically on a timer, but can also be safely called manually, e.g. from tests.
+func (s *RemotelyControlledSampler) UpdateSampler() {
+ res, err := s.samplingFetcher.Fetch(s.serviceName)
+ if err != nil {
+ s.metrics.SamplerQueryFailure.Inc(1)
+ s.logger.Infof("failed to fetch sampling strategy: %v", err)
+ return
+ }
+ strategy, err := s.samplingParser.Parse(res)
+ if err != nil {
+ s.metrics.SamplerUpdateFailure.Inc(1)
+ s.logger.Infof("failed to parse sampling strategy response: %v", err)
+ return
+ }
+
+ s.Lock()
+ defer s.Unlock()
+
+ s.metrics.SamplerRetrieved.Inc(1)
+ if err := s.updateSamplerViaUpdaters(strategy); err != nil {
+ s.metrics.SamplerUpdateFailure.Inc(1)
+ s.logger.Infof("failed to handle sampling strategy response %+v. Got error: %v", res, err)
+ return
+ }
+ s.metrics.SamplerUpdated.Inc(1)
+}
+
+// NB: this function should only be called while holding a Write lock
+func (s *RemotelyControlledSampler) updateSamplerViaUpdaters(strategy interface{}) error {
+ for _, updater := range s.updaters {
+ sampler, err := updater.Update(s.sampler, strategy)
+ if err != nil {
+ return err
+ }
+ if sampler != nil {
+ s.logger.Debugf("sampler updated: %+v", sampler)
+ s.sampler = sampler
+ return nil
+ }
+ }
+ return fmt.Errorf("unsupported sampling strategy %+v", strategy)
+}
+
+// -----------------------
+
+// ProbabilisticSamplerUpdater is used by RemotelyControlledSampler to parse sampling configuration.
+type ProbabilisticSamplerUpdater struct{}
+
+// Update implements Update of SamplerUpdater.
+func (u *ProbabilisticSamplerUpdater) Update(sampler SamplerV2, strategy interface{}) (SamplerV2, error) {
+ type response interface {
+ GetProbabilisticSampling() *sampling.ProbabilisticSamplingStrategy
+ }
+ var _ response = new(sampling.SamplingStrategyResponse) // sanity signature check
+ if resp, ok := strategy.(response); ok {
+ if probabilistic := resp.GetProbabilisticSampling(); probabilistic != nil {
+ if ps, ok := sampler.(*ProbabilisticSampler); ok {
+ if err := ps.Update(probabilistic.SamplingRate); err != nil {
+ return nil, err
+ }
+ return sampler, nil
+ }
+ return newProbabilisticSampler(probabilistic.SamplingRate), nil
+ }
+ }
+ return nil, nil
+}
+
+// -----------------------
+
+// RateLimitingSamplerUpdater is used by RemotelyControlledSampler to parse sampling configuration.
+type RateLimitingSamplerUpdater struct{}
+
+// Update implements Update of SamplerUpdater.
+func (u *RateLimitingSamplerUpdater) Update(sampler SamplerV2, strategy interface{}) (SamplerV2, error) {
+ type response interface {
+ GetRateLimitingSampling() *sampling.RateLimitingSamplingStrategy
+ }
+ var _ response = new(sampling.SamplingStrategyResponse) // sanity signature check
+ if resp, ok := strategy.(response); ok {
+ if rateLimiting := resp.GetRateLimitingSampling(); rateLimiting != nil {
+ rateLimit := float64(rateLimiting.MaxTracesPerSecond)
+ if rl, ok := sampler.(*RateLimitingSampler); ok {
+ rl.Update(rateLimit)
+ return rl, nil
+ }
+ return NewRateLimitingSampler(rateLimit), nil
+ }
+ }
+ return nil, nil
+}
+
+// -----------------------
+
+// AdaptiveSamplerUpdater is used by RemotelyControlledSampler to parse sampling configuration.
+// Fields have the same meaning as in PerOperationSamplerParams.
+type AdaptiveSamplerUpdater struct {
+ MaxOperations int
+ OperationNameLateBinding bool
+}
+
+// Update implements Update of SamplerUpdater.
+func (u *AdaptiveSamplerUpdater) Update(sampler SamplerV2, strategy interface{}) (SamplerV2, error) {
+ type response interface {
+ GetOperationSampling() *sampling.PerOperationSamplingStrategies
+ }
+ var _ response = new(sampling.SamplingStrategyResponse) // sanity signature check
+ if p, ok := strategy.(response); ok {
+ if operations := p.GetOperationSampling(); operations != nil {
+ if as, ok := sampler.(*PerOperationSampler); ok {
+ as.update(operations)
+ return as, nil
+ }
+ return NewPerOperationSampler(PerOperationSamplerParams{
+ MaxOperations: u.MaxOperations,
+ OperationNameLateBinding: u.OperationNameLateBinding,
+ Strategies: operations,
+ }), nil
+ }
+ }
+ return nil, nil
+}
+
+// -----------------------
+
+type httpSamplingStrategyFetcher struct {
+ serverURL string
+ logger log.DebugLogger
+}
+
+func (f *httpSamplingStrategyFetcher) Fetch(serviceName string) ([]byte, error) {
+ v := url.Values{}
+ v.Set("service", serviceName)
+ uri := f.serverURL + "?" + v.Encode()
+
+ // TODO create and reuse http.Client with proper timeout settings, etc.
+ resp, err := http.Get(uri)
+ if err != nil {
+ return nil, err
+ }
+
+ defer func() {
+ if err := resp.Body.Close(); err != nil {
+ f.logger.Error(fmt.Sprintf("failed to close HTTP response body: %+v", err))
+ }
+ }()
+
+ body, err := ioutil.ReadAll(resp.Body)
+ if err != nil {
+ return nil, err
+ }
+
+ if resp.StatusCode >= 400 {
+ return nil, fmt.Errorf("StatusCode: %d, Body: %s", resp.StatusCode, body)
+ }
+
+ return body, nil
+}
+
+// -----------------------
+
+type samplingStrategyParser struct{}
+
+func (p *samplingStrategyParser) Parse(response []byte) (interface{}, error) {
+ strategy := new(sampling.SamplingStrategyResponse)
+ if err := json.Unmarshal(response, strategy); err != nil {
+ return nil, err
+ }
+ return strategy, nil
+}