opentelemetry-collector/processor/samplingprocessor/tailsamplingprocessor/sampling/policy.go

76 lines
2.7 KiB
Go

// 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 (
"sync"
"time"
tracepb "github.com/census-instrumentation/opencensus-proto/gen-go/trace/v1"
"go.opentelemetry.io/collector/consumer/consumerdata"
)
// TraceData stores the sampling related trace data.
type TraceData struct {
sync.Mutex
// Decisions gives the current status of the sampling decision for each policy.
Decisions []Decision
// Arrival time the first span for the trace was received.
ArrivalTime time.Time
// Decisiontime time when sampling decision was taken.
DecisionTime time.Time
// SpanCount track the number of spans on the trace.
SpanCount int64
// ReceivedBatches stores all the batches received for the trace.
ReceivedBatches []consumerdata.TraceData
}
// Decision gives the status of sampling decision.
type Decision int32
const (
// Unspecified indicates that the status of the decision was not set yet.
Unspecified Decision = iota
// Pending indicates that the policy was not evaluated yet.
Pending
// Sampled is used to indicate that the decision was already taken
// to sample the data.
Sampled
// NotSampled is used to indicate that the decision was already taken
// to not sample the data.
NotSampled
// Dropped is used when data needs to be purged before the sampling policy
// had a chance to evaluate it.
Dropped
)
// PolicyEvaluator implements a tail-based sampling policy evaluator,
// which makes a sampling decision for a given trace when requested.
type PolicyEvaluator interface {
// 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.
OnLateArrivingSpans(earlyDecision Decision, spans []*tracepb.Span) error
// Evaluate looks at the trace data and returns a corresponding SamplingDecision.
Evaluate(traceID []byte, trace *TraceData) (Decision, error)
// OnDroppedSpans is called when the trace needs to be dropped, due to memory
// pressure, before the decision_wait time has been reached.
OnDroppedSpans(traceID []byte, trace *TraceData) (Decision, error)
}