TLDR Tech / Data
Sampling: the philosopher's stone of distributed tracing
Distributed tracing, powered by OpenTelemetry, is essential for modern observability but generates massive volumes of span data that outpace current querying capabilities. Sampling (primarily via head or tail methods) remains vital to control scale and cost: head sampling offers deterministic, stateless selection, while tail sampling enables context-aware retention but introduces significant architectural and operational complexity, particularly in multi-zone environments and accurate RED metric production. Practical implementations require smart routing, metric extraction before sampling, and a clear understanding of trade-offs. Emerging solutions like disk-based buffering and exemplar-based sampling offer incremental improvements.
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