> ## Documentation Index
> Fetch the complete documentation index at: https://checklyhq.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Best Practices for Detecting Downtime | Incident Response

> Discover how to implement multi‑layered monitoring, smart alerts, third‑party checks, failure drills & global probes to catch outages fast and reduce revenue loss

Downtime can be costly—leading to lost revenue, frustrated users, and damage to your brand’s reputation. As a  developer, ensuring high availability and quickly detecting outages is critical.

## **1. Implement Multi-Layered Monitoring**

Relying on a single monitoring method can lead to blind spots. Instead, use a combination of:

* **Synthetic Monitoring** (Probes): Simulate user interactions from different locations to detect failures before real users do.
* **Application Monitoring**: Gather traces internal from your application, and look for errors or long timespans that indicate trouble. Send logs to a single locality to help you investigate problems after one is detected.
* **Infrastructure Monitoring**: Use tools like Prometheus, Grafana, or Nagios to keep an eye on the underlying health of your system.

## **2. Set Up Intelligent Alerting**

Avoid "alert fatigue" by ensuring alerts are meaningful and actionable:

* **Use Multi-Signal Confirmation**: Trigger alerts only when multiple checks fail (e.g., HTTP status + latency + DNS resolution). For example, Checkly makes it easy to require 2 or more failures before sending alerts in its [retry configuration](https://www.checklyhq.com/docs/communicate/alerts/configuration).
* **Prioritize Alerts**: Distinguish between *critical* (full outage) and *warning* (degraded performance). Any time your on-call team gets an alert that doesn’t require action, this should be counted as a false alarm and call for improvements to your alert thresholds.
* **Avoid Static Thresholds**: When a service that usually responds in 4.98 seconds starts responding after 5.1 seconds, it’s a negative trend that might call for some investigation. But it certainly does *not* call for a midnight alert to the on-call team. As just one example, Playwright’s assertions about page elements use an [auto-waiting](https://www.checklyhq.com/blog/playwright-auto-waiting/) system that is more flexible than static time thresholds.

## **3. Monitor Third-Party Dependencies**

Your application may depend on APIs, CDNs, or cloud providers—any of which can fail.

* **Check External Endpoints**: Regularly test third-party services. With [Checkly’s API monitors](https://www.checklyhq.com/docs/api-checks/), you can send frequent quick checks to external API’s you rely on, and get reliable notifications if something isn’t working, before users report a problem.
* **Implement Fallbacks**: Gracefully degrade functionality if a dependency fails. For core dependencies this might go as far as switching to a backup payment provider if your primary service fails.

## **4. Test Failure Scenarios**

Proactively simulate outages to ensure your monitoring works:

* **Monitor Proactively**: Use synthetic monitoring to send requests to your service. Ideally a [sophisticated automation tool like Playwright](https://www.checklyhq.com/guides/playwright-testing-to-monitoring/) to simulate full user paths. For example on your eCommerce site Playwright could test the process of visiting the site, browsing inventory, adding items to a cart, and checking out.
* **Chaos Engineering**: Large teams with dedicated platform engineers can use tools like Chaos Monkey to intentionally break systems and verify detection.
* **Run Scheduled Drills**: Periodically trigger false outages to test alerting responsiveness. Note this is only necessary if you aren’t having frequent real incidents! It is useful to schedule a drill whenever the process for incident management changes, so that your team has a chance for a dry run of the procedure.

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## **5. Ensure Global Visibility**

Downtime may only affect certain regions due to DNS, CDN, or cloud provider issues.

* **Distributed Monitoring**: Deploy checks across multiple geographic locations.
* **Monitor DNS & CDN Health**: Use tools like Checkly to [detect regional outages](https://www.checklyhq.com/docs/monitoring/global-locations/).

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## **6. Automate Incident Response**

When downtime occurs, speed is crucial.

* **Auto-Remediation**: For known issues (e.g., a stuck process), automatically restart services. Tools like Kubernetes have automatic remediation as part of their core function.
* **Escalation Policies**: Ensure alerts reach the right team (SMS, Slack, PagerDuty). And that incidents are tracked when the team is responding.
* **Postmortem Culture**: Analyze outages to improve future detection.

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## **Conclusion**

Detecting downtime quickly requires a proactive, multi-layered approach. By combining synthetic checks, real-user monitoring, intelligent alerting, and global visibility, you can minimize downtime and maintain a reliable user experience.

**Further Reading:**

* [Reducing Mean Time to Repair](https://www.checklyhq.com/learn/incidents/mttr-challenges/)