Datadog
Architecture & the Agent
Understand how Datadog collects metrics, traces, and logs through a single host Agent and a SaaS backend.
Datadog is a SaaS observability platform that unifies metrics, traces, logs, and more behind one query layer and one set of dashboards. The data plane begins with the Datadog Agent — a lightweight process installed on each host, container node, or as a sidecar — that collects system metrics, runs hundreds of integration checks, tails logs, and receives application traces.
A building with a smart meter in every room reporting to one utility dashboard. You do not store the readings yourself — the utility keeps the history and lets you slice usage by room, floor, or hour.
Key Concepts
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The Agent forwards everything over TLS to Datadog's backend, where data is indexed and made queryable within seconds. Because Datadog is fully hosted, you never run the storage or query tier yourself: you trade per-host, per-GB, and per-million-events pricing for zero operational burden. The platform's signature feature is correlation — a single tag set (service, env, version) lets you pivot from a metric spike to the traces behind it to the logs of the exact request.