Diagnosing high CPU usage | Virteche Cloud

Identifying the culprit

# Basic: shows CPU-sorted process list, updated every 3 seconds
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# Better interactive view
apt install htop && htop

# Snapshot of the top 15 CPU consumers
ps aux --sort=-%cpu | head -15

Common causes and fixes

Web server (Nginx / Apache) overloaded

Check request rate:

tail -f /var/log/nginx/access.log | awk '{print $1}' | sort | uniq -c | sort -rn | head

Mitigation: Add rate limiting in Nginx, enable caching, or upgrade to a plan with more vCPUs.

Database queries running hot

# MySQL / MariaDB — show running queries
mysql -e "SHOW PROCESSLIST;"

# PostgreSQL
sudo -u postgres psql -c "SELECT pid, query, state FROM pg_stat_activity WHERE state != 'idle';"

Crypto-mining malware

Signs: CPU consistently near 100%, unknown process names, network activity to mining pool IPs.

ps aux | grep -i "xmrig\|minerd\|cpuminer"
netstat -antp | grep ESTABLISHED | grep -v sshd

If you find malware, take a snapshot immediately, then terminate the server and redeploy from a clean image. Change all passwords and rotate SSH keys. Open a security ticket — we can assist with forensic analysis.

Runaway cron job or script

# Identify by time — if a process has been running for hours
ps -eo pid,etime,cmd | sort -k2 -r | head

# Check cron logs
grep CRON /var/log/syslog | tail -20