Operations, Reliability & FinOps · Guide

Infrastructure and Application Health Monitoring

Defines layered health models, health endpoints, dependency monitoring, golden signals, and automated remediation for cloud infrastructure and applications.

Purpose

This standard defines how teams monitor the health of cloud infrastructure, platforms, applications, managed services, dependencies, and critical user journeys. Health monitoring must determine whether a service is capable of performing its intended function—not merely whether a virtual machine or container process is running.

Scope

The requirements apply to compute, containers, Kubernetes, serverless services, databases, storage, messaging, integration platforms, networks, DNS, identity, secrets, certificates, APIs, web applications, data pipelines, and AI inference or retrieval services across Azure, AWS, GCP, and OCI.

Health model

Service health is evaluated across five layers:

LayerQuestionExamples
ProviderIs the cloud service or region degraded?Provider incidents, maintenance, quota or capacity constraints
ResourceIs the provisioned resource operational?VM state, node readiness, database availability, storage errors
PlatformCan the shared platform deliver its service?DNS resolution, identity issuance, ingress, cluster scheduling, secrets retrieval
ApplicationCan the workload execute correctly?API success, dependency calls, job completion, data correctness
User journeyCan a user complete the business transaction?Login, search, checkout, file upload, report generation

A green resource state does not prove application or user-journey health. Each critical service must therefore implement health signals at multiple layers.

Reference architecture

flowchart TB P[Cloud provider health] --> CORR[Health correlation engine] R[Resource and platform metrics] --> CORR A[Application health endpoints] --> CORR S[Synthetic transactions] --> CORR U[Real-user and business outcomes] --> CORR C[Change and deployment events] --> CORR CORR --> VIEW[Service health model] VIEW --> SLO[SLO evaluation] VIEW --> ALERT[Actionable alerts] VIEW --> AUTO[Automated remediation] VIEW --> STATUS[Internal/external status communication]

Health endpoint design

Applications and platform components should expose separate endpoint semantics:

EndpointMeaningUse
LivenessProcess is not irrecoverably stuckRestart decision only; must not depend on every external service
ReadinessInstance can safely receive trafficLoad-balancer or orchestrator routing
StartupApplication initialization is still progressingPrevent premature liveness failure during slow startup
Deep healthKey internal and external dependencies are functionalService dashboard and diagnostics, not necessarily restart logic

Poorly designed probes can create outages. A liveness probe that fails because a downstream database is unavailable can restart every application instance and worsen recovery. Readiness may reflect a dependency failure when traffic cannot be served, but probe behavior must prevent cascading failure and restart loops.

Health endpoint controls

  • Endpoints MUST be lightweight, deterministic, authenticated or network-restricted where detailed diagnostics are exposed.
  • Public health endpoints MUST NOT disclose versions, hostnames, dependency topology, secrets, or stack traces.
  • Readiness logic MUST account for connection-pool exhaustion, initialization, and critical dependency state.
  • Health checks MUST have timeouts shorter than their evaluation interval and must not create material load.
  • Probe settings MUST be validated under startup delay, dependency failure, CPU saturation, and network latency.

Infrastructure monitoring baseline

Compute and operating systems

Monitor availability, CPU saturation, run queue, memory pressure, paging, disk latency and capacity, filesystem inodes, network errors, time synchronization, agent health, certificate expiry, patch state, and reboot requirements. Static thresholds alone are insufficient; baselines and workload-specific limits are required.

Kubernetes and container platforms

Monitor control-plane health where exposed, node readiness, scheduling failures, pod restart loops, unavailable replicas, pending workloads, CPU and memory throttling, persistent-volume errors, ingress failure, DNS, certificate expiry, autoscaler limits, image-pull failures, policy denial, and cluster/version lifecycle.

Managed databases and storage

Monitor connection saturation, query latency, deadlocks, replication lag, failover state, backup status, storage growth, transaction log pressure, throttling, IOPS/throughput limits, cache hit rate, error rates, data freshness, and maintenance events. Provider metrics must be supplemented with application-level query and transaction outcomes.

Networks and identity

Monitor DNS resolution, route reachability, firewall denial trends, load-balancer backend health, packet loss, latency, private endpoint resolution, VPN/interconnect health, certificate chains, identity-provider availability, token issuance latency, federation failures, and permission-denied trends.

Application monitoring baseline

For request-based systems, implement the following:

  • Request rate and concurrency.
  • Successful request ratio based on business outcome, not only HTTP status.
  • Latency percentiles, not averages alone.
  • Dependency latency and error rate.
  • Queue depth, age, and dead-letter volume.
  • Cache effectiveness and eviction.
  • Thread, connection, worker, and rate-limit saturation.
  • Version, feature flag, and deployment annotations.
  • Business transaction completion and reconciliation.

For batch and data workloads, monitor start delay, completion time, freshness, completeness, schema validity, duplicate or missing records, reconciliation, retry behavior, and downstream publication.

For AI applications, monitor inference availability, latency, token usage, model/provider throttling, retrieval availability, retrieval latency, groundedness or quality evaluation signals, safety-control activation, fallback behavior, and prompt or model version. Quality metrics must be defined carefully; a successful HTTP response is not proof of a correct AI outcome.

Golden signals and saturation

flowchart LR T[Traffic / demand] --> SVC[Service] SVC --> L[Latency] SVC --> E[Errors] SVC --> SAT[Saturation] SAT --> LIM[Hard limits and quotas] L --> UX[User experience] E --> UX LIM --> FAIL[Non-linear failure risk]

Health monitoring must include hard limits such as IP exhaustion, subnet capacity, provider quotas, connection counts, API rate limits, certificate expiration, partition limits, storage limits, and token/request quotas. These often fail abruptly; they require predictive alerts with sufficient remediation time.

Dependency monitoring

Every Tier 0–2 service must maintain a dependency inventory that identifies:

  • owning team and support path;
  • dependency SLO or provider commitment;
  • timeout, retry, circuit-breaker, caching, and fallback behavior;
  • failure mode and blast radius;
  • observability source;
  • recovery and communication path.

Retries must use bounded attempts, exponential backoff, jitter, and idempotency where needed. Unbounded synchronized retries convert partial degradation into systemic failure.

Automated remediation

Automation may restart, reschedule, scale, fail over, clear known transient state, or switch to a documented fallback when:

  1. the condition is unambiguous;
  2. the action is reversible or low risk;
  3. rate limits and blast-radius controls exist;
  4. actions are logged and correlated to the incident;
  5. repeated remediation escalates instead of looping indefinitely.

Destructive recovery, data failover, credential rotation, and broad traffic shifts require stronger authorization and validation.

Multi-cloud service mapping

CapabilityAzureAWSGCPOCI
Provider/resource healthService Health, Resource HealthAWS Health, CloudWatchPersonalized Service Health, Cloud MonitoringService announcements, OCI Monitoring
Synthetic checksApplication Insights availability tests / Azure Load Testing patternsCloudWatch SyntheticsCloud Monitoring uptime checksOCI Health Checks
VM monitoringAzure Monitor Agent / VM InsightsCloudWatch Agent / Systems ManagerOps AgentManagement Agent / OCI Monitoring
KubernetesAzure Monitor managed Prometheus and Container InsightsContainer Insights / Managed PrometheusGCP Managed Service for Prometheus / GKE observabilityOCI Monitoring plus Prometheus/Grafana patterns for OKE
Application healthApplication InsightsCloudWatch Application Signals / X-RayCloud Trace, Error Reporting, custom metricsOCI APM

Validation

A service is operationally monitorable only when:

  • dashboards show user journey, application, platform, and provider layers;
  • alerts identify business impact, affected region/version, and likely dependency;
  • a deployment can be correlated with health changes;
  • monitoring detects controlled failure tests;
  • operators can distinguish resource failure from dependency or application failure;
  • hard limits and lifecycle deadlines are forecast;
  • health information remains available during a workload outage.

Minimum compliance checklist

  • Critical user journeys have synthetic or equivalent outcome monitoring.
  • Liveness, readiness, startup, and deep-health semantics are separated.
  • Infrastructure, platform, application, and provider health are correlated.
  • Dependencies and hard limits are inventoried and monitored.
  • Batch, data, and AI workloads use outcome-specific health measures.
  • Automated remediation has guardrails and loop prevention.
  • Dashboards and alerts are validated through controlled failure testing.

Terminology

TermDefinition
SLIA quantitative measure of service behavior, such as successful request ratio or latency.
SLOA target value or range for an SLI over a defined measurement window.
SLAA formal commitment that may include contractual remedies. It is not a substitute for an internal SLO.
Error budgetThe permitted unreliability implied by an SLO. For a 99.9% availability objective, the error budget is 0.1% over the same window.
RTOMaximum targeted elapsed time to restore a service after disruption.
RPOMaximum targeted data-loss interval measured backward from the disruption.
MTTD / MTTA / MTTRMean time to detect, acknowledge, and restore or recover. Definitions must be fixed in the metric catalog.
ToilRepetitive, manual, automatable operational work that does not create durable service improvement.

References

The following sources define the external baseline used by this standard. Provider features, regional availability, licensing, and product names must be verified during implementation.

  1. Microsoft Azure Well-Architected Framework
  2. AWS Well-Architected Framework
  3. GCP Well-Architected Framework
  4. Oracle Cloud Infrastructure Architecture Center
  5. OpenTelemetry documentation
  6. Google Site Reliability Engineering resources
  7. FinOps Framework
  8. NIST SP 800-61 Rev. 3: Incident Response Recommendations and Considerations for Cybersecurity Risk Management