Observability That Survives Provider Outages: Metrics, Traces and Synthetic Checks

When a major cloud or CDN provider blinks, will you know or be surprised?

Provider outages in late 2025 and early 2026 exposed a recurring gap: teams often discover degradation from customers or public outage dashboards instead of their own monitoring. If you run distributed systems, you need observability that survives provider outages — not observability that collapses with a single vendor. This guide gives an actionable design: which synthetics, traces and logs and external health checks to run, how to wire alerts and SLOs, and how to validate coverage before the next incident.

Top-level summary: what to do first (inverted pyramid)

• Run multi-region blackbox synthetics for core APIs and frontends, from at least 3 independent networks.
• Instrument vendor-neutral traces (OpenTelemetry) and capture minimal, high-cardinality logs you can still access during outages.
• External health checks and BGP/DNS monitors to detect provider-level routing issues.
• Design SLO-based alerts that require corroboration across checks and regions to avoid false positives.
• Prepare failover notification paths and a provider-outage runbook that doesn't depend on the provider being healthy.

Why traditional observability fails during provider outages

Monitoring systems are often deployed within the same cloud, or rely on provider-managed agents and control planes. When that provider has a control-plane or network incident, your telemetry pipeline (metrics ingestion, tracing collector, log shipping) can become partially or wholly unavailable. The result: dashboards go stale, alerts stop firing, and teams are blind.

Common failure modes:

• Telemetry ingestion endpoints unreachable because the cloud region's egress is broken.
• Agent-side SDKs unable to reach vendor collectors (blocking log/trace export).
• Notifications routed through provider-managed channels fail.
• Dependency graph visibility collapses because traces from certain services are absent.

2026 trends shaping resilient observability

Recent industry trends (late 2025–early 2026) that change the playbook:

• OpenTelemetry is the de facto tracing and metrics lingua franca. Most vendors and major clouds provide OpenTelemetry-compatible ingestion and local distributions, enabling easier vendor-neutral collectors.
• Edge and regional third-party synthetic providers have proliferated — synthetic checks are now cheaper and more geographically distributed. Consider edge-first, cost-aware synthetic placement as part of your plan.
• AI-assisted anomaly detection is used for triage, but it's not a replacement for deterministic external checks.
• SLO tooling matured — platforms support composite SLOs and cross-region error budgets, making outage-aware alerting simpler. See recommendations on hybrid/edge SLO design in hybrid observability architectures.

Design principle: independent control planes

Guarantee that at least one observability control path is independent of the provider you are trying to monitor. That means:

• Collect synthetics and edge checks from third-party networks (not just your cloud).
• Ship critical health logs and heartbeats to an external storage/collector that does not rely on your primary cloud's availability.
• Use vendor-neutral formats like OpenTelemetry for traces and metrics to switch collectors if needed.

Which synthetics to run — the practical checklist

Not all synthetic checks are equal. Choose a toolbox that gives you both high signal and low false positives.

1. Basic HTTP/HTTPS health checks (blackbox)

• What: simple GET/HEAD checks for status codes and latency.
• Why: fastest way to detect ingress and edge failures.
• How often: 30–60s for critical endpoints; 1–5m for lower-priority APIs.
• From: at least 3 independent networks/regions (e.g., North America, EU, APAC) using different ISPs. Many teams combine SaaS synthetics with lightweight on-prem or alternate-cloud runners described in edge-first strategies.

2. Multi-step browser synthetics

• What: simulate real user flows using Playwright or Puppeteer (login, transaction, checkout).
• Why: catches client-side and CDN issues invisible to simple HTTP checks.
• Frequency: 5–15 minutes for core user journeys.

3. API contract and schema checks

• What: verify JSON schema and contract responses for critical APIs, and assert business invariants.
• Why: detects subtle failures where endpoints return 200 but broken data.

4. Port/TCP and TLS handshake tests

• What: TCP connect and TLS negotiation for custom protocols or non-HTTP services.
• Why: surface network-level problems and certificate issues.

5. Background job and queue health checks

• What: synthetic producers/consumers that validate queueing systems and worker pipelines.
• Why: many outages manifest as back-pressure rather than immediate errors.

Where to place synthetics and blackbox monitoring

Placement matters.

• Run checks from external providers and SaaS synthetic platforms that route through public internet, not via your cloud VPC.
• Include at least one set of checks executed from an on-prem or alternate cloud location (your backup region).
• Validate checks from mobile network IPs for mobile-app critical flows.

Traces and logs: what to keep during outages

Detailed traces are essential for root cause analysis, but large trace volumes become noisy. Design for minimal survivability.

Tracing strategy

• Use OpenTelemetry to ensure vendor neutrality and the ability to redirect exporters.
• Always export a reduced, critical trace stream to an external collector or storage (sampling + tail-based sampling).
• Instrument dependency calls (DB, external APIs, CDN, auth provider) with explicit spans and error annotations so you can map provider failures in traces.

Example: minimal OpenTelemetry exporter config (pseudo YAML) to send to an external collector:

# otel-collector.yaml
receivers:
  otlp:
    protocols:
      http:
processors:
  batch:
exporters:
  otlp/http/external:
    endpoint: https://external-collector.example.com/v1/traces
service:
  pipelines:
    traces:
      receivers: [otlp]
      processors: [batch]
      exporters: [otlp/http/external]

Logging strategy

• Ship critical logs (auth failures, deployment hooks, outage heartbeats) to an external store with lower retention but guaranteed availability.
• Use structured logs (JSON) and include trace/span IDs to rehydrate traces when full telemetry returns.
• Keep a lightweight log-forwarder that can buffer to disk and retry to external endpoints; avoid brokers that only live inside the affected provider.

External health checks beyond HTTP

Provider outages often show up first in routing, DNS, or BGP. Add checks that specifically look for those failure modes.

• DNS resolution checks: verify authoritative and recursive resolution globally and validate RRSIG/TLSA where relevant. For small teams building an "outage checklist" see Outage-Ready: a Small Business Playbook.
• BGP/route monitoring: subscribe to third-party BGP monitors or services that detect prefix hijacks or propagation issues — field reviews of compact distributed control-plane gateways can help you think about routing and visibility (compact gateways review).
• Edge cache validation: fetch assets from edge locations to verify CDN health and cache headers; see ideas for edge-first micro-metrics.
• Dependency provider checks: synthetic requests specifically to critical third-party APIs (auth, payments, identity providers) to detect their outages early.

SLOs and alerting that survive the outage

Alerting during provider incidents must be reliable and actionable. Use SLOs and composite rules.

SLO design

• Create SLOs per customer-facing journey, not per infrastructure metric.
• Derive SLOs from external synthetics (blackbox) as one primary signal; internal metrics/traces are secondary.
• Define composite SLOs that aggregate across regions and external providers; require majority failure across regions to escalate to P1. See architecture guidance for hybrid/edge SLOs in hybrid observability.

Example SLO rule (conceptual):

# Composite SLO: API availability
window: 30d
objective: 99.95%
sources:
  - synthetic_checks: /api/transactions
  - synthetic_checks: /api/auth
aggregation: region-majority

Alerting principles

• Corroboration: Alert only when multiple independent signals fail (e.g., 3+ external regions, DNS check, and synthetic API check).
• Non-dependent channels: Route initial P1 alerts to external paging providers (SMS, phone, alternate Slack workspace) that don't rely on the affected provider. Small teams should read Outage-Ready for channel planning.
• Escalation playbooks: Automatic runbook links and next steps in the alert payload. Keep the runbook stored outside the affected provider (e.g., public S3 alternative or documentation site on a different CDN).
• Heartbeat monitors: Monitor a predictable heartbeat metric; missing heartbeats for >N intervals triggers an outage mode with manual confirmation steps.

Runbooks and playbooks: prepare, test, and reduce cognitive load

Write concise, action-driven runbooks that assume limited telemetry availability. Include:

• Primary detection checklist: which synthetic checks to validate and in which order.
• Isolation steps: how to confirm provider vs app issue (DNS flush, alternate region curl, direct IP probe).
• Mitigation steps: how to fail traffic to another provider or region, or how to switch to a degraded service mode.
• Communication templates for customers and internal stakeholders.

Runbooks are only useful if practiced. Schedule provider-outage tabletop and live drills using simulated failures of your primary cloud or CDN.

Coverage matrix: know what you monitor and what you don't

Create a simple coverage matrix to find blind spots. Rows are critical user journeys and infrastructure dependencies. Columns are telemetry types: synthetics (HTTP, browser), traces, logs, DNS, BGP, and on-call notification. Mark who owns the check and frequency.

Example (conceptual):

• Checkout flow — browser synthetics (5m), API contract check (30s), trace sampling (1%), logs shipped externally (yes), BGP/DNS (yes)
• Auth provider — API check (30s), schema check (1m), trace spans on auth calls, external log backup (yes)

Practical implementation recipes

Recipe: lightweight external HTTP blackbox with curl + cron

#!/bin/bash
URL=https://api.example.com/health
HTTP_CODE=$(curl -s -o /dev/null -w "%{http_code}" --max-time 10 $URL)
if [ "$HTTP_CODE" -ne 200 ]; then
  echo "Health check failed: $URL returned $HTTP_CODE" | mail -s "PROVIDER-OUTAGE-CANDIDATE: $URL" ops@example.com
fi

Run from multiple external locations or use a simple containerized job in a different cloud provider. If you're evaluating monitoring tools and cost impacts, the Top Cloud Cost Observability Tools roundup is a helpful starting point.

Recipe: Playwright multi-step synthetic for a login+checkout

const { chromium } = require('playwright');
(async () => {
  const browser = await chromium.launch();
  const page = await browser.newPage();
  await page.goto('https://shop.example.com');
  await page.click('text=Sign in');
  await page.fill('#email', 'synthetic@example.com');
  await page.fill('#password', 'P@ssw0rd');
  await page.click('text=Sign in');
  await page.click('text=Add to cart');
  await page.click('text=Checkout');
  // assert success element
  await page.waitForSelector('.order-confirmation', { timeout: 10000 });
  await browser.close();
})();

Testing and validation: run outage drills

Schedule quarterly provider-outage drills. Simulate a variety of scenarios:

• Region-network partition: synthetic checks fail from a region but internal metrics look fine.
• Control-plane outage: agent collectors can't reach vendor collectors.
• DNS/provider routing failure: BGP or DNS checks fail but your app in another region is healthy.

Validate that:

• P1 alerts go to the backup paging channel.
• Runbooks are followed and lead to action within the expected SLA.
• Post-incident telemetry and logs are sufficient for a 2-hour RCA.

Common pitfalls and how to avoid them

• Over-reliance on a single provider for observability: split critical telemetry exports across two collection endpoints (primary and failover). Hybrid/edge patterns help here — see hybrid observability architectures.
• False positives from noisy synthetics: use majority-vote across regions before paging.
• Too many alerts during outages: implement incident-mode silencing for low-value alerts and only escalate core SLO breaches.
• Missing ownership: map each synthetic and alert to a named owner and update during rotations.

Actionable takeaways — what to implement this week

1. Deploy at least three external blackbox HTTP checks for your primary customer journeys across distinct networks.
2. Instrument and export a reduced trace stream via OpenTelemetry to an external collector (even if sampled).
3. Create a provider-outage runbook and store it outside the primary provider's control plane (the Beyond Restore guide has good UX notes).
4. Define composite SLOs that use external synthetics as the primary source and configure corroboration-based alerts.
5. Schedule a provider-outage drill this quarter and validate notification paths. Small teams can use the planning checklist in Outage-Ready.

Final thoughts: observability as resilience

Provider outages are inevitable. The question is whether they become catastrophic. Observability that survives outages is a combination of choice and design: choose vendor-neutral formats (OpenTelemetry), choose independent execution points for synthetics and external checks, design corroborated SLO alerts, and practice regularly. These investments reduce time-to-detect, time-to-respond, and customer impact. For tooling and cost trade-offs, the cloud observability tool review is a practical reference.

Call to action

If you want a ready-made checklist and runbook templates to run a provider-outage drill, download our Provider-Outage Observability Kit or sign up for a workshop with details.cloud. Run the drill, fix the gaps, and sleep better when the next outage arrives.