How Uptime Monitoring Works

What SiteWatch checks

SiteWatch sends an HTTP HEAD request to your site every 5 minutes and measures:

• Status code: Is the server responding with a 2xx or 3xx (success/redirect)?
• Response time: How fast did the server respond in milliseconds?
• HTTPS redirect: Does the HTTP version correctly redirect to HTTPS?
• www consistency: Do the www and non-www versions behave consistently?

An uptime check is considered failed when the server returns a 4xx/5xx error, the connection times out (10 seconds), DNS resolution fails, the connection is refused, or there's an SSL error.

How to read your results

• OK (green): Your site responded successfully with a status code between 200 and 399.
• Warning (amber): Your site responded, but it was slow (over 3 seconds).
• Critical (red): Your site is down or unreachable.

SiteWatch uses transient protection: it takes 2 consecutive failures before triggering an alert. A single failed check won't create a notification — this prevents false alarms from brief network hiccups.

Common issues and fixes

Site is down (connection timeout)

The server isn't responding at all. Possible causes:

• Server is crashed or stopped: SSH into your server and check if your web server (nginx, Apache, Puma) is running. Restart it with systemctl restart nginx or equivalent.
• DNS is broken: Use dig yourdomain.com to check if DNS resolves correctly. If not, check your DNS provider.
• Firewall blocking: Make sure ports 80 and 443 are open. Check with ufw status or your cloud provider's security groups.
• Server overloaded: Check CPU and memory with htop. If the server is out of resources, you may need to upgrade or optimize your application.

Connection refused

The server is reachable but not accepting connections on port 80/443. This usually means your web server process isn't running.

# Check if nginx is running
systemctl status nginx

# Check if anything is listening on port 443
ss -tlnp | grep :443

SSL error

The HTTPS connection couldn't be established. This is often a certificate issue — check the SSL monitor for details.

Slow response (warning)

SiteWatch alerts when response time exceeds 3 seconds. This doesn't mean your site is down, but visitors will have a poor experience. Common causes:

• Database queries taking too long
• No server-side caching
• Application server running out of threads/workers
• Server located far from your users (no CDN)

See the Performance guide for optimization tips.

HTTP to HTTPS redirect

SiteWatch checks whether http://yoursite.com correctly redirects to https://yoursite.com. If it doesn't, users who type your URL without https:// will get an insecure connection.

nginx fix:

server {
    listen 80;
    server_name yoursite.com www.yoursite.com;
    return 301 https://$host$request_uri;
}

www/non-www inconsistency

SiteWatch checks if both yoursite.com and www.yoursite.com behave consistently. If both serve content independently without redirecting, search engines may index duplicate content.

Fix: Pick one (www or non-www) and redirect the other:

# nginx: redirect www to non-www
server {
    listen 443 ssl;
    server_name www.yoursite.com;
    return 301 https://yoursite.com$request_uri;
}