68 lines
2.2 KiB
Go
68 lines
2.2 KiB
Go
// Copyright 2019, OpenTelemetry Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package sampling
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import (
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"time"
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tracepb "github.com/census-instrumentation/opencensus-proto/gen-go/trace/v1"
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)
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type rateLimiting struct {
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currentSecond int64
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spansInCurrentSecond int64
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spansPerSecond int64
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}
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var _ PolicyEvaluator = (*rateLimiting)(nil)
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// NewRateLimiting creates a policy evaluator the samples all traces.
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func NewRateLimiting(spansPerSecond int64) PolicyEvaluator {
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return &rateLimiting{
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spansPerSecond: spansPerSecond,
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}
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}
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// OnLateArrivingSpans notifies the evaluator that the given list of spans arrived
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// after the sampling decision was already taken for the trace.
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// This gives the evaluator a chance to log any message/metrics and/or update any
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// related internal state.
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func (r *rateLimiting) OnLateArrivingSpans(earlyDecision Decision, spans []*tracepb.Span) error {
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return nil
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}
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// Evaluate looks at the trace data and returns a corresponding SamplingDecision.
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func (r *rateLimiting) Evaluate(traceID []byte, trace *TraceData) (Decision, error) {
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currSecond := time.Now().Unix()
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if r.currentSecond != currSecond {
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r.currentSecond = currSecond
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r.spansInCurrentSecond = 0
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}
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spansInSecondIfSampled := r.spansInCurrentSecond + trace.SpanCount
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if spansInSecondIfSampled < r.spansPerSecond {
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r.spansInCurrentSecond = spansInSecondIfSampled
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return Sampled, nil
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}
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return NotSampled, nil
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}
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// OnDroppedSpans is called when the trace needs to be dropped, due to memory
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// pressure, before the decision_wait time has been reached.
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func (r *rateLimiting) OnDroppedSpans(traceID []byte, trace *TraceData) (Decision, error) {
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return Sampled, nil
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}
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