Guide topic
Website and server troubleshooting guides
Troubleshooting guides for website outages, HTTP errors, server disk, CPU and memory pressure, Nginx 502 responses, databases, DNS, HTTPS, WordPress, and service dependencies.
Troubleshooting
Understand the system, not just the setting.
Fast troubleshooting starts by identifying the failing layer and preserving evidence before changing the system. These guides work from observable symptoms toward DNS, network, TLS, proxy, application, database, resource, and dependency causes.
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Start with the problem you are solving.
Server disk full: how to find what used the space
A full server disk can break websites, databases, logs, package updates, and backups. Diagnose filesystem, inode, log, database, cache, upload, and deleted-file usage before deleting data.
TroubleshootingServer memory usage: how to read RAM pressure
High server memory usage is not automatically a problem. Learn free vs available memory, cache, swap, OOM kills, process growth, and how to tell normal caching from real pressure.
TroubleshootingServer CPU high: how to identify the workload
High server CPU can come from traffic, PHP workers, databases, compression, backups, malware, cron jobs, builds, or runaway processes. Find the process and trigger before scaling.
TroubleshootingNginx bad gateway: how to troubleshoot a 502
An Nginx 502 Bad Gateway usually means the proxy could not get a usable response from its upstream. Check process health, sockets, ports, timeouts, permissions, and upstream logs.
TroubleshootingDatabase connection failed: how to check the whole path
A database connection failure can involve DNS, host, port, firewall, service state, TLS, credentials, privileges, connection limits, or application configuration.
TroubleshootingMySQL connections limit: what “too many connections” means
MySQL connection limits protect database resources. Learn why applications exhaust connections, how pooling and slow queries contribute, and when increasing the limit is appropriate.
TroubleshootingWhy is my website down? A troubleshooting checklist
Work through DNS, TLS, HTTP, application, database, resource, and provider checks in a useful order when a website stops loading.
TroubleshootingHTTP 500, 502 and 503 errors explained for website owners
Learn what HTTP 500, 502 and 503 errors usually indicate, which layer to investigate, what evidence to collect, and when restarting a service is not the real fix.
WordPressWordPress database error: how to narrow the cause
A WordPress database error can come from credentials, database availability, corrupted tables, resource limits, disk problems, or plugin queries. Diagnose the layer before changing data.
WordPressWordPress white screen: how to troubleshoot safely
A WordPress white screen often means a hidden PHP failure, exhausted resource, plugin conflict, or theme problem. Collect evidence before randomly disabling components.
LinuxSSH connection refused: separate service, port and firewall failures
SSH connection refused usually means the host actively rejected the TCP connection. Check destination, port, sshd listening state, bind address, firewall, and recent changes.
DNSDomain not resolving: how to find the broken DNS layer
When a domain is not resolving, check registration status, delegation, authoritative nameservers, zone records, DNSSEC, and recursive results in that order.
SecurityHTTPS not working: test DNS, TLS and web-server layers
If HTTPS is not working, confirm DNS reaches the right server, port 443 is reachable, the TLS handshake succeeds, the certificate matches, and the web server has the correct virtual host.
cPanelcPanel error logs: where to look when a site breaks
cPanel exposes recent website errors, while server and application logs may contain deeper detail. Learn which log to check for PHP, Apache, cPanel, mail, and system failures.