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This lesson explains how telemetry is collected and sent into Datadog so you can observe what’s happening across your applications and infrastructure. It covers the primary telemetry types, where they originate, and practical guidance for designing a scalable ingestion strategy.

Telemetry types at a glance

Telemetry typically falls into four categories. Each type serves distinct use cases and has different volume and retention characteristics:
Telemetry typeWhat it measuresCommon sourcesTypical retention / use case
MetricsNumeric time-series (counts, gauges, histograms)Host agents, custom app metrics, cloud servicesShort-term high-resolution for alerts; aggregated long-term for trends
LogsUnstructured or structured event recordsApplication logs, system logs, audit trailsHigh volume; filter/sampling to reduce cost
TracesDistributed request flows across servicesApplication instrumentation (APM)Sampled for performance debugging and root cause analysis
ProfilesCPU/memory/heap and runtime profilesProfilers, APM integrationsUsed for performance optimizations; lower volume but high value
For Datadog-specific implementation details see the Datadog documentation: https://docs.datadoghq.com/

Where telemetry originates

Telemetry can come from many places across your environment:
  • End-user devices (browsers, mobile apps, IoT/wearables)
  • Infrastructure (VMs, containers, serverless functions)
  • Cloud provider services and managed platforms
  • On-premises servers and legacy systems
  • Third-party integrations and partner data feeds
  • Custom instrumentation in business-critical services
Thinking in terms of a monitoring-first architecture helps you decide what to collect and where:
Architecture layerRoleWhere to collect telemetry
Entry layerIngress and edge (API gateways, load balancers)Request/edge logs, synthetic monitoring, edge metrics
Business logic layerApplication services and business rulesTraces, service metrics, application logs
Data / storage layerDatabases and storage systemsDB query metrics, I/O metrics, audit logs
This subdivision helps implement controls, apply security boundaries, and determine optimal collection points. In modern systems, data sources emit a large and continuous volume of telemetry. That volume can quickly become costly and noisy if not managed intentionally.
The image is an infographic showing how telemetry flows into a monitoring platform, specifically Datadog, from various sources including devices, cloud providers, on-premise servers, and other avenues. It highlights data sources like customer applications, cloud providers, and collected partner data.

Designing a scalable ingestion strategy

Because telemetry volume grows rapidly, treat ingestion as a design decision rather than an afterthought. Use the following practices to keep cost and noise under control while preserving observability value.
AreaRecommended practiceWhy it matters
Source selectionEnable only the integrations and agents you needReduces noise and ingestion costs
Sampling & filteringSample high-volume traces; filter or redact verbose logsKeeps signal-to-noise ratio high and controls storage
Tagging & metadataApply consistent tags and service namesEnables efficient querying and reduces cardinality issues
Rate limits & quotasConfigure agent-side and collector-side limitsPrevents accidental spikes from overwhelming ingestion
Retention & tiersUse short-term high-resolution + long-term aggregated storageBalances cost with the ability to investigate historical issues
Practical checklist:
  • Start with availability, performance, and error telemetry for critical services.
  • Validate the business value before increasing retention or instrumenting additional sources.
  • Apply consistent naming conventions and tags across services.
  • Set log sampling rules and trace sampling rates per service.
  • Monitor ingestion metrics (bytes ingested, events/sec, cardinality) for anomalies.
When designing ingestion, prioritize telemetry that answers your key questions: Is the service available? Is performance within SLO? Are errors rising? Begin with essential telemetry, validate its value, then expand integrations and retention as needed.
High-cardinality tags and unfiltered verbose logs are common causes of unexpected costs and query slowness. Apply tag governance and log-reduction rules early to avoid runaway ingestion bills.

Tips for implementation

  • Use official Datadog agents and integrations where possible to simplify collection and security.
  • For cloud-native environments, instrument at the service level (APM + traces) and rely on exporters for metrics (e.g., Prometheus exporters).
  • Implement structured logging to make logs searchable and to enable efficient parsing and indexing.
  • Leverage telemetry sampling: adjust trace sampling dynamically for high-traffic endpoints.
  • Monitor your observability platform’s own telemetry (ingestion rates, costs, quota usage) and set alerts on unexpected changes.
Further reading and references: That’s it for this lesson. Apply these principles when designing your telemetry ingestion pipeline to keep your observability effective and sustainable.

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