DNS Issues – When Your Application Becomes Unreachable

The Scenario: Everything’s Working – Except No One Can Reach You

Users start reporting that they can’t access your app. You brace for impact, expecting something to be on fire in the backend, but everything checks out. Servers are fine. Logs are clean. The app is up and running – except for the fact that things are maybe a bit too quiet…

Then you find it: DNS – the bridge between users and your infrastructure. If that link breaks, even a healthy system becomes invisible. And because DNS isn’t part of your core app stack, it’s easy to overlook – until it fails.

Common triggers include:

• Expired domains
• Misconfigured DNS records
• Outages at the DNS provider level

Once you’ve identified DNS as the root cause, it’s time to act fast.

The Quick Fix: Restore DNS Resolution

Your priority now is to get users back in. That means restoring DNS functionality as quickly and cleanly as possible:

• Domain renewal: Renew the domain if it has expired.
• DNS configuration: Roll back or correct any incorrect or outdated DNS settings.
• Backup provider: If your DNS provider is down, switch to a backup provider (if available).

Keep in mind that even after fixing the issue, DNS propagation can take time. That’s why clear communication is key – let users know what’s happening and provide temporary workarounds, like a temporary IP address, if possible.

The Long-Term Fix: Design for DNS Failure

DNS issues are disruptive, but also somewhat preventable. To avoid the same scenario in the future, bake resilience into your DNS strategy:

• Multiple providers: Use multiple DNS providers to reduce dependency on a single point of failure.
• Configuration audits: Audit and test your DNS configurations regularly to catch errors early.
• Monitoring & alerts: Set up monitoring and alerts to detect resolution failures before users notice.
• Renewal reminders: Of no automation is available, put domain renewal reminders in place to avoid losing access over an expired domain.

In Short

Your app can be running perfectly but if DNS fails, it’s as good as offline. These issues are often simple in nature – expired domains, misconfigurations, or provider outages – but their impact is huge: your users can’t connect, and your service becomes invisible. The best defense is preparation. By adding redundancy, validating your DNS setup regularly, and monitoring it like any other critical service, you can reduce the risk of downtime and respond faster when things break. DNS may not be part of your application code, but it is part of your user experience – so treat it with the same care.

Stay tuned,
Matthias

This blog post is part of our multi-part series, where we describe common software outages and help you resolve them quickly. You can find all other posts under Foreword: Navigating the Storms of Software Outages.