I came across an interesting read this morning on head-based probabilistic sampling in OpenTelemetry SDKs. I didn't realise for Node.js it's the default spec, and that you just need to configure the sampling rate. In @Elastic EDOT that's via sampling_rate or OTEL_TRACES_SAMPLER_ARG. See image for code for OTel SDK.

Article: https://www.elastic.co/observability-labs/blog/how-we-fixed-head-based-sampling-in-opentelemetry