Guides 5 min read
How to Create a Status Page Customers Trust
A status page tells customers what is broken, what you are doing and when to check back. How to set one up, what to put on it and ready-to-use incident update templates.
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Step-by-step guides to monitoring websites, APIs, cron jobs, SSL certificates, DNS and servers, with checklists you can apply to your own setup today.
Guides 7 min read
SLA vs SLO vs SLI: Definitions, Examples and How to Set Them
An SLI measures how a service behaves, an SLO is the target for that measurement and an SLA is the promise to customers. Definitions, downtime tables and how to set each one.
ReadGuides 6 min read
DNS_PROBE_FINISHED_NXDOMAIN: Causes and Fixes for Site Owners
DNS_PROBE_FINISHED_NXDOMAIN means the domain name could not be found in DNS. What causes it on the site owner side, how to check with dig and nslookup, and how to prevent it.
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DNS Monitoring: How to Detect Changed or Hijacked Records
A changed DNS record can send your visitors or email somewhere else without a single error. How DNS monitoring works, which records to watch and what to do when one changes.
ReadAgencies 7 min read
What to Monitor on Your Website: A Checklist of URLs and Checks
Monitoring only the homepage misses most outages. A checklist of the URLs and checks that matter, from login and checkout to webhooks, cron jobs, SSL, DNS and servers, with example setups.
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SSL Certificate Errors Explained: Causes and Fixes
NET::ERR_CERT_DATE_INVALID, ERR_CERT_COMMON_NAME_INVALID and the other browser SSL warnings explained: what each one means, what causes it and how to fix it on your server.
ReadGuides 4 min read
SSL Certificate Monitoring: Never Miss a Renewal Again
An expired SSL certificate turns your site into a browser warning. Why certificates still expire with auto-renewal, what to monitor and how to set reminders that work.
ReadGuides 7 min read
HTTP Status Codes Cheat Sheet for Website Monitoring
Which HTTP status codes mean your site is down, which are fine and which depend on the endpoint. A monitoring-focused cheat sheet covering 1xx to 5xx, redirects, 401, 403, 429 and 5xx errors.
ReadGuides 6 min read
How to Monitor Cron Jobs with Heartbeats
Cron jobs fail silently. A heartbeat monitor alerts you when a scheduled job does not check in on time. How heartbeats work, how to add one to a crontab and which settings to choose.
ReadGuides 8 min read
503 Service Unavailable: What It Means and How to Fix It
A 503 Service Unavailable error means the server is reachable but cannot handle the request right now. The common causes, how to fix each one and how monitoring catches 503s early.
ReadGuides 8 min read
Cron Expressions Explained: Syntax, Examples and Common Mistakes
A cron expression is five fields that say when a job runs. The syntax, special characters and @daily shortcuts, ready-to-use examples and the time zone and PATH mistakes that break jobs.
ReadGuides 5 min read
What Is Uptime Monitoring? How It Works and What 99.9% Really Means
Uptime monitoring checks your website or API on a schedule and alerts you when it fails. How checks work, which interval to choose and what uptime percentages mean in minutes.
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