/
rate_limiting.go
74 lines (62 loc) · 2.42 KB
/
rate_limiting.go
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// Copyright The OpenTelemetry Authors
//
// 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 sampling
import (
"time"
"go.uber.org/zap"
"go.opentelemetry.io/collector/consumer/pdata"
)
type rateLimiting struct {
currentSecond int64
spansInCurrentSecond int64
spansPerSecond int64
logger *zap.Logger
}
var _ PolicyEvaluator = (*rateLimiting)(nil)
// NewRateLimiting creates a policy evaluator the samples all traces.
func NewRateLimiting(logger *zap.Logger, spansPerSecond int64) PolicyEvaluator {
return &rateLimiting{
spansPerSecond: spansPerSecond,
logger: logger,
}
}
// OnLateArrivingSpans notifies the evaluator that the given list of spans arrived
// after the sampling decision was already taken for the trace.
// This gives the evaluator a chance to log any message/metrics and/or update any
// related internal state.
func (r *rateLimiting) OnLateArrivingSpans(Decision, []*pdata.Span) error {
r.logger.Debug("Triggering action for late arriving spans in rate-limiting filter")
return nil
}
// Evaluate looks at the trace data and returns a corresponding SamplingDecision.
func (r *rateLimiting) Evaluate(_ pdata.TraceID, trace *TraceData) (Decision, error) {
r.logger.Debug("Evaluating spans in rate-limiting filter")
currSecond := time.Now().Unix()
if r.currentSecond != currSecond {
r.currentSecond = currSecond
r.spansInCurrentSecond = 0
}
spansInSecondIfSampled := r.spansInCurrentSecond + trace.SpanCount
if spansInSecondIfSampled < r.spansPerSecond {
r.spansInCurrentSecond = spansInSecondIfSampled
return Sampled, nil
}
return NotSampled, nil
}
// OnDroppedSpans is called when the trace needs to be dropped, due to memory
// pressure, before the decision_wait time has been reached.
func (r *rateLimiting) OnDroppedSpans(pdata.TraceID, *TraceData) (Decision, error) {
r.logger.Debug("Triggering action for dropped spans in rate-limiting filter")
return Sampled, nil
}