Performance monitoring basics in Express - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Understanding CPU usage output from a monitoring tool

You run a command to check CPU usage on a server and get this output:

CPU Usage: 85%

What does this output mean?

A The CPU is idle 85% of the time

B The CPU temperature is 85 degrees

C The CPU is busy 85% of the time

D The CPU usage is below 15%

💡 Hint

CPU usage shows how busy the processor is, not temperature or idle time.

CPU usage percentage tells how much time the CPU spends doing work. 85% means it is busy most of the time.

🧠 Conceptual

intermediate

Purpose of monitoring memory usage in applications

Why is it important to monitor memory usage in a running application?

A To check disk space availability

B To see how fast the CPU is running

C To measure network speed

D To check if the application is using too much memory and might crash

💡 Hint

Memory issues can cause crashes or slowdowns.

Monitoring memory helps detect leaks or excessive use that can cause crashes or poor performance.

🔀 Workflow

advanced

Steps to set up basic performance monitoring on a Linux server

Which sequence correctly describes the steps to set up basic performance monitoring using common Linux tools?

A 2,1,3,4

B 1,2,3,4

C 1,3,2,4

D 4,1,2,3

💡 Hint

Think about installing first, then running, analyzing, and alerting last.

You first install tools, then run them to collect data, analyze that data, and finally set alerts.

❓ Troubleshoot

advanced

Identifying cause of high disk I/O in monitoring logs

Your monitoring logs show very high disk I/O on a server. Which of these is the most likely cause?

A A process is reading and writing large files frequently

B The CPU is overheating

C The network connection is slow

D The server has low memory usage

💡 Hint

Disk I/O relates to reading and writing data on disk.

High disk I/O means a process is doing many read/write operations on the disk.

✅ Best Practice

expert

Choosing the best metric to monitor for web server responsiveness

Which metric is best to monitor to understand if a web server is responding quickly to user requests?

A Average response time per request

B CPU temperature

C Disk space usage

D Number of open network ports

💡 Hint

Think about what shows how fast the server replies to users.

Average response time directly measures how quickly the server handles requests.