# Observability
All Observability notes →5 — Label & Attribute Schema Design
Cardinality budget, naming conventions, and the high-churn label traps that turn a cheap metric into a production incident — the design discipline for the labels semantic conventions don't already cover for you.
1 — OpenTelemetry SDKs & Semantic Conventions
OpenTelemetry is a specification and an API/SDK, not a backend — the pieces that make it up, and the semantic-convention vocabulary that lets two unrelated teams' telemetry be queried the same way.
4 — Auto vs. Manual Instrumentation
Four ways a span gets created — hand-written, framework-level auto-instrumentation, eBPF, and service-mesh sidecar capture — and the trade-off between code changes and business context each one makes.
9 — OTel Collector Pipeline Design
Receivers, processors, and exporters chained into a pipeline; why a platform runs more than one; and the agent/gateway topology that tail sampling specifically forces on that design.
10 — Collector Pipelines
Covers composing multiple named pipelines in one Collector for signal-specific or team-specific routing.
11 — Processors
Covers batching, filtering, attribute-mutation, and tail-sampling processors and the order sensitivity of a processor chain.
12 — Exporters
Covers configuring multiple concurrent exporters and the retry/queueing behavior that protects against backend outages.
13 — Connectors
Covers connectors that derive one signal type from another inside the Collector, e.g. generating span metrics from trace data.
14 — Scaling Collectors
Covers horizontally scaling Collector fleets — load balancing, trace-ID-hash routing for tail sampling, and per-tier resource sizing.
2 — OTLP Protocol
Covers the OTLP wire protocol — its protobuf schema and gRPC/HTTP transport — as the common export format across signals.
3 — SDK Internals
Covers how an OTel SDK turns instrumentation calls into batched, exported telemetry — processors, exporters, and the pipeline between them.
5 — Manual Instrumentation
Covers hand-written spans, metrics, and log correlation for business-specific telemetry auto-instrumentation cannot infer.
6 — Semantic Conventions
Covers OTel's shared attribute vocabulary and why consistent naming is what makes two teams' telemetry queryable together.
7 — Resources
Covers Resource attributes — the identity of the process/host/service emitting telemetry — as distinct from per-signal attributes.