Tempo

https://grafana.com/blog/2020/10/27/announcing-grafana-tempo-a-massively-scalable-distributed-tracing-system/

Grafana Labs is proud to announce an easy-to-operate, high-scale, and cost-effective distributed tracing system: Tempo. Tempo is designed to be a robust trace id lookup store whose only dependency is object storage (GCS/S3).

https://grafana.com/oss/tempo/

https://laiyuanyuan-sg.medium.com/mock-solutions-for-golang-unit-test-a2b60bd3e157

https://github.com/inexio/thola
https://git.sr.ht/~sircmpwn/dowork