Guides

Reliability, Explained Without the Hand-Waving

Everything we have learned about keeping services up and alerts trustworthy, written out properly. No gated PDFs, no signup.

What Is Uptime?Uptime meaning explained: how to calculate uptime percentage, what 99.9% and 99.99% allow in downtime, what counts as downtime and what a good target is. 7 min read
What Is Uptime Monitoring?A practical introduction to uptime monitoring: how synthetic checks work, how they differ from real-user monitoring, and what each one misses. 8 min read
Uptime Monitoring Services ComparedHow to choose an uptime monitoring service, and a fair, dated comparison of SutramX, UptimeRobot, Better Stack, Pingdom, Freshping and Opsgenie. 8 min read
SLA, SLI & SLO ExplainedA clear explanation of service level indicators, objectives, and agreements — including error budgets and how to choose targets you can actually meet. 9 min read
Reducing False AlertsPractical techniques for eliminating false positive alerts: cross-region confirmation, retry logic, flap detection, and choosing the right thresholds. 8 min read
Preventing SSL Expiry OutagesAutomated renewal has not eliminated certificate outages. Here are the failure modes that still take sites down, and how to detect them before they do. 7 min read
Incident Response BasicsA practical incident response framework for small teams — from detection through communication to blameless postmortems. 10 min read
Status Page Best PracticesHow to run a status page that actually reduces support load — update cadence, tone, what to disclose, and why hosting location matters. 7 min read
Monitoring APIs EffectivelyHow to monitor APIs properly with contract assertions, latency budgets, authenticated probes, and dependency-aware health checks. 9 min read
Choosing Check IntervalsThe arithmetic behind monitoring frequency: detection time, request load, cost, and how to choose intervals per endpoint tier. 7 min read
Why Your Monitor Reports 403 While Your Site WorksHow to recognise and fix a monitor that is being blocked by Cloudflare, Vercel, AWS WAF, or another bot protection layer rather than detecting a real outage. 6 min read
How to Fix 502 Bad GatewayWhat a 502 Bad Gateway error means, the common causes behind nginx, load balancers and Cloudflare, how to diagnose it step by step, and how to monitor for it. 10 min read
How to Fix 503 Service UnavailableWhat a 503 Service Unavailable error means: overload, maintenance, no healthy backends, rate limits and WAF challenges. How to diagnose, fix and monitor it. 10 min read
How to Fix 504 Gateway TimeoutWhat a 504 Gateway Timeout means, the timeout limits in nginx, AWS load balancers and Cloudflare, how to find the slow layer, and how to fix and monitor it. 10 min read
Why Is My Website Down?A practical checklist for when your website is down: is it just you, DNS, domain or SSL expiry, hosting, CDN, a deploy or a firewall, and how to tell users. 11 min read
Cron Job MonitoringHow to monitor cron jobs, backups and queue workers with heartbeat pings: grace periods, failure pings, late vs failed vs hung runs and crontab examples. 9 min read
DNS MonitoringWhy DNS outages happen (expired domains, bad record edits, NS changes, DNSSEC) and which records to monitor: A, AAAA, CNAME, MX, NS and TXT values. 9 min read
Domain Expiry MonitoringWhy domains expire despite auto-renew, how to check expiry with RDAP and WHOIS, what grace and redemption periods mean, and when to send expiry alerts. 8 min read
MTTR, MTTD, MTTA & MTBF ExplainedMTTR, MTTD, MTTA and MTBF defined, with formulas, a worked example, the four meanings of MTTR, and practical ways to reduce each number. 9 min read
On-Call RotationHow to set up an on-call rotation: weekly, follow-the-sun and primary/secondary patterns, handoffs, escalation policies, fatigue, pay and small teams. 9 min read
Postmortem TemplateA copy-ready blameless postmortem template: summary, impact, timeline, contributing factors and action items, plus a fully filled-in fictional example. 10 min read
Synthetic vs Real User MonitoringSynthetic monitoring vs RUM: how each works, what each catches and misses, cost and privacy trade-offs, and when to run both alongside uptime checks. 9 min read
How to Monitor MCP ServersWhat "up" means for a Model Context Protocol server: transports, the initialize handshake, tools/list, auth, latency and tool drift, and how to check each. 9 min read
Site Not Loading on Jio or AirtelWhy a website loads on one Indian ISP but not Jio or Airtel: DNS, blocks, IPv6, routing, TLS/SNI and carrier NAT, with diagnosis steps for users and owners. 10 min read

A suggested reading order

Each guide stands on its own, but they build on each other. Read together they take about 209 minutes. If you are setting up monitoring for the first time, this order follows the decisions in the order you will meet them.

  1. Start here: what uptime means, what a synthetic check is, what it misses, how to choose a service and how often to check. What Is Uptime?, What Is Uptime Monitoring?, Uptime Monitoring Services Compared and Choosing Check Intervals.
  2. Then make alerts trustworthy: confirmation and retries, checks that look at the response rather than just the status code, certificates, and monitors blocked by bot protection. Reducing False Alerts, Monitoring APIs Effectively, Preventing SSL Expiry Outages and Why Your Monitor Reports 403 While Your Site Works.
  3. Then set targets and handle incidents: availability targets and error budgets, what to do when something breaks, and how to tell your users. SLA, SLI & SLO Explained, Incident Response Basics and Status Page Best Practices.
  4. Run on-call and learn from incidents: who gets paged and when, the recovery and detection numbers worth tracking, and a postmortem you can reuse. On-Call Rotation, MTTR, MTTD, MTTA & MTBF Explained and Postmortem Template.
  5. Monitor more than web pages: scheduled jobs, DNS records, domain renewals and MCP servers, and how synthetic checks compare with real-user monitoring. Cron Job Monitoring, DNS Monitoring, Domain Expiry Monitoring, How to Monitor MCP Servers and Synthetic vs Real User Monitoring.
  6. When a site is down right now: how to tell whose problem it is, what the common gateway errors mean, and why a site can fail on one Indian network only. Why Is My Website Down?, How to Fix 502 Bad Gateway, How to Fix 503 Service Unavailable, How to Fix 504 Gateway Timeout and Site Not Loading on Jio or Airtel.

Already running monitors and getting too many alerts? Skip straight to the second group. Writing or reviewing an SLA? The SLO guide and the free SLA uptime calculator answer most questions between them.

To put numbers on what you read, the free reliability tools turn uptime targets, check intervals and incident timings into concrete figures. To see how these practices apply to a SaaS product, an online store or a side project, read the monitoring use cases; to weigh SutramX against the tools you already know, see how SutramX compares.

Common Questions

Frequently Asked Questions

Where should I start if I am new to uptime monitoring?
Read What Is Uptime Monitoring? first: it explains how synthetic checks work and what they cannot see. Choosing Check Intervals and Reducing False Alerts come next, because interval and confirmation settings decide whether your alerts are worth answering. Start with What Is Uptime Monitoring?
Why does my monitor report 403 while my site works in a browser?
Usually a bot protection layer such as Cloudflare, Vercel or AWS WAF is blocking the monitor's requests, not your site failing. The firewall guide shows how to recognise it and the ways to let monitoring traffic through. Read the firewall guide
Do I need a SutramX account to use the guides?
No. Every guide is free to read without signing up, and the practices they cover, such as check intervals, outage confirmation, SLOs and incident response, apply whichever monitoring tool you use.
How are the guides different from the docs?
The guides explain monitoring practice and the reasoning behind it. The docs explain how to do specific things in SutramX, such as creating a monitor, routing alerts or publishing a status page. Browse the docs

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