There are two major components included here.
The original specification for consistent probability sampling is defined by
https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/tracestate-probability-sampling.md
and open-telemetry/opentelemetry-specification#2047.
It supports sampling probabilities that are power of 2 (1, 1/2, 1/4, ...), and uses 8-bit r-value and 8-bit p-value in tracestate.
The implementation of this proposal is contained by the package io/opentelemetry/contrib/sampler/consistent in this repository and provides various Sampler implementations.
- ConsistentSampler: abstract base class of all consistent sampler implementations below
- ConsistentAlwaysOffSampler: see https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/tracestate-probability-sampling.md#always-off-sampler
- ConsistentAlwaysOnSampler: see https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/tracestate-probability-sampling.md#always-on-consistent-probability-sampler
- ConsistentComposedAndSampler: allows combining two consistent samplers and samples when both samplers would sample
- ConsistentComposedOrSampler: allows combining two consistent sampler and samples when at least one of both samplers would sample, see https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/tracestate-probability-sampling.md#requirement-combine-multiple-consistent-probability-samplers-using-the-minimum-p-value
- ConsistentParentBasedSampler: see https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/tracestate-probability-sampling.md#parentconsistentprobabilitybased-sampler
- ConsistentProbabilityBasedSampler: see https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/trace/tracestate-probability-sampling.md#consistentprobabilitybased-sampler
- ConsistentRateLimitingSampler: a rate limiting sampler based on exponential smoothing that dynamically adjusts the sampling probability based on the estimated rate of spans occurring to satisfy a given rate of sampled spans
The current version of the specification for consistent probability sampling is described by https://github.com/open-telemetry/oteps/blob/main/text/trace/0235-sampling-threshold-in-trace-state.md. It uses 56 bits for representing rejection threshold, which corresponds to a much wider range of sampling probabilities than the original proposal.
The implementation of the current proposal is contained by the package io/opentelemetry/contrib/sampler/consistent56 in this repository and provides implementation for a number of different Samplers.
- ConsistentSampler abstract base class for all consistent sampler implementations
- ComposableSampler: interface used to build hierarchies of Samplers, see Composite Samplers
- ConsistentAlwaysOffSampler:
- ConsistentAlwaysOnSampler:
- ConsistentAnyOfSampler: allows combining several consistent samplers; it samples when at least one of them would sample,
- ConsistentParentBasedSampler:
- ConsistentFixedThresholdSampler: consistent probability sampler that uses a predefined sampling probability
- ConsistentRateLimitingSampler: a rate limiting sampler based on exponential smoothing that dynamically adjusts the sampling probability based on the estimated rate of spans occurring to satisfy a given rate of sampled spans
- ConsistentRuleBasedSampler a sampler that performs stratified sampling by evaluating qualifying conditions and propagating the sampling decision from one of its delegate samplers
- Otmar Ertl, Dynatrace
- Peter Findeisen, Cisco
Learn more about component owners in component_owners.yml.