What performance monitoring means here
Process monitoring answers whether a service is alive. Performance monitoring asks a different question: how well is it behaving while it is alive?
For this first pass, I focused on a small set of signals that are easy to observe on an Ubuntu server.
CPU usage
CPU shows whether the server is under pressure from active work. htop is a useful first view because it makes spikes, load, and process-level usage easy to scan.
sudo apt-get install htop
htop
High CPU is not always bad. The question is whether the usage matches expected traffic and whether it stays high after the request load drops.
Memory usage
Memory matters for Django because workers, database clients, and background processes can grow over time. The key check is whether memory rises and returns to a stable range or keeps climbing.
Useful commands:
free -h
ps aux --sort=-%mem | head
Response checks
A service can look healthy at the process level but still respond slowly. curl gives a quick HTTP-level view:
curl -I https://example.com
For deeper work, response time, error rate, and logs need to be collected over time.
Takeaway
The first monitoring habit is to separate server pressure from application behavior. CPU and memory explain what the machine is feeling. HTTP checks and logs explain what users are experiencing.
