Observability Platform  ·  View 02 of 25  ·  Context and scope

High-Level Architecture

Six stages from emission to reading, and the point where the two paths separate and never rejoin.

Editable source SVG draw.io All views
Emit OTel SDK in-process Node agent ADOT DaemonSet Admit Gateway tier OTel Collector Cardinality admission budget per service Redaction before write Reduce Aggregate metric path — unsampled Tail sampler 45 s hold, whole traces Log class reduction by declared class Buffer Ingest buffer Amazon MSK Store Metric store Mimir on S3 Trace store Tempo on S3 Log store ClickHouse on S3 Exemplar index DynamoDB Read Alert evaluation independent plane Query & consoles Managed Grafana unsampled evidence unsampled only aggregate to trace Observability Platform — High-Level Architecture Application we own Security / platform Interface / broker Decision point Queue / topic Data store synchronous event / async Two paths leave the gateway and never rejoin except through the exemplar index, which carries pointers and never quantities. v 1.0 · owner Reliability Architecture · date 2026-09

Decisions

  • Admission comes before reduction. Cardinality and redaction are enforced where data enters, not where it lands, so a bad label is a rejection at the gateway rather than a store failure at 3 a.m.
  • One durable buffer sits between admission and every writer, which makes each store independently replayable and removes their recovery objectives from the platform's RPO story.
  • Object storage is the retention substrate for all three signals, so retention is a storage-class decision and query capacity scales without moving data.

Stack, and why

  • OpenTelemetry Collector for collection and admission, Amazon MSK as the buffer, Mimir, Tempo and ClickHouse over S3 for storage, DynamoDB for the exemplar index, Amazon Managed Grafana for consoles.
  • AWS was chosen because it is the least-delivered stack in this practice; observability belongs to no particular cloud, so the topic is free to rotate. The requirement stays vendor-neutral outside section 1 of ask.md.

Deliberately omitted

  • Per-signal writer counts, shard topology and the control plane are all left to views 09, 10 and 19. This view carries the shape of the pipeline and the location of the split, and nothing else.
◀  System Context All views Actors and Their Core Journeys  ▶
Solution Architecture v1.0 · Amazon Web Services with open-source collection and storage · Reliability Architecture · 2026-09 · 25 views02-high-level-architecture