[LINUX] NGINX HIGH LOAD URL FINDER - fourslickz/notes GitHub Wiki

To identify high load URLs in Nginx, you can analyze the access logs to find which URLs are receiving the most requests or consuming the most resources. This is usually done by parsing the Nginx access logs and summarizing the data to find heavy hitters.

Steps to Find High Load URLs in Nginx

  1. Check Nginx Access Logs Nginx access logs typically contain information about each request, including the requested URL, request time, and response code.

The default location for Nginx logs is:

Access log: /var/log/nginx/access.log Error log: /var/log/nginx/error.log If your logs are in a custom location, you can check the log path in the Nginx configuration (/etc/nginx/nginx.conf).

  1. Use awk or grep to Find High-Traffic URLs You can use awk, grep, and sort to analyze the Nginx access logs to find the most requested URLs.

Here’s a command to extract and count the URLs:

bash Copy code awk '{print $7}' /var/log/nginx/access.log | sort | uniq -c | sort -nr | head -n 10 Explanation: awk '{print $7}': This extracts the requested URL from each line in the log file (assuming $7 is the column for the URL in the default Nginx log format). sort: Sorts the URLs. uniq -c: Counts the occurrences of each URL. sort -nr: Sorts the counted URLs in descending order by the number of requests. head -n 10: Displays the top 10 most frequently requested URLs. 3. Check Slow-Loading or High Response Time URLs If you’re interested in finding URLs that are slow to load or consume the most resources (instead of just the most requested ones), you can analyze the request time from the logs. You need to make sure the Nginx log format includes the $request_time variable.

Update Log Format (if necessary): If $request_time isn’t already in your logs, you can add it to your Nginx log format in the nginx.conf:

nginx Copy code log_format timed_combined '$remote_addr - $remote_user [$time_local] "$request" ' '$status $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for" ' '$request_time'; And use this format for your access log:

nginx Copy code access_log /var/log/nginx/access.log timed_combined; Find URLs with High Response Time: Once you have $request_time in your logs, you can find URLs with the highest load time:

bash Copy code awk '{print $7, $11}' /var/log/nginx/access.log | sort -k2 -nr | head -n 10 Explanation: $7: Extracts the URL. $11: Extracts the request time (assuming it’s the 11th field in the log format). sort -k2 -nr: Sorts by the second field (request time) in descending order. head -n 10: Shows the top 10 URLs with the highest load times. 4. Monitor with Tools If you want real-time or more advanced analysis, consider using tools like:

GoAccess: A real-time web log analyzer with visual reports. Elastic Stack (ELK): For centralized log management and analysis with Elasticsearch, Logstash, and Kibana. Grafana + Prometheus: For monitoring and alerting with Nginx metrics. For example, GoAccess can be used to analyze logs with a command like this:

bash Copy code goaccess /var/log/nginx/access.log -o report.html --log-format=COMBINED This will generate an HTML report showing statistics on URLs, load times, and more.

By using these methods, you can pinpoint high-traffic URLs or those with long request times, helping you optimize your Nginx server performance.