🔧Troubleshooting High CPU Usage in Linux

A Step-by-Step Guide:

High CPU usage on a Linux server can slow things down, but with the right approach, you can quickly resolve the issue. Here’s how I tackle it:

1️⃣ Identify Resource-Heavy Processes: Use $top or $htop to see which processes are consuming the most CPU. Alternatively, run

$ps aux --sort=-%cpu        

2️⃣ Check System Logs for Clues: Logs in /var/log/syslog or /var/log/messages can reveal errors or unusual activity causing the spike.

3️⃣ Analyze Historical Data: Tools like $pidstat help track resource usage over time, giving you deeper insights into CPU behavior.

To use pidstat command, you need to install it first by the command

$sudo apt install sysstat        

USE: To monitor a process by its PID (e.g., 1234):

$pidstat -p 1234 2          

This shows detailed CPU stats for that process every 2 seconds.

4️⃣ Inspect Running Applications: Look for rogue scripts, misbehaving applications, or spikes in server workload that might overload the CPU.

5️⃣ Optimize Resource Usage: Use nice or renice to adjust process priorities. To limit CPU for a specific process, try cpulimit.

• nice: Launch a process with a specific priority. Lower priority (higher nice value) ensures it doesn’t interfere with critical tasks. Example:

$nice -n 10 <process_name>        

• renice: Change the priority of an already running process. Example:

$renice -n 5 -p <PID>        

Priority Range:

• Values range from -20 (highest priority) to 19 (lowest priority). Be cautious with negative values, as they can impact system performance.

To use cpulimit command, you should install it first with the command

$sudo apt install cpulimit        

USE:

$cpulimit --pid 17918 --limit 50        

6️⃣ Monitor CPU Trends: Use monitoring tools like Grafana, Prometheus, or Nagios to track usage over time and proactively identify patterns.

7️⃣ Plan for Scalability: If high CPU usage is frequent, consider scaling up (upgrading hardware) or scaling out (distributing workloads).

💡 Pro Tip: Regular monitoring and proactive resource management can help prevent CPU issues before they impact performance.

Have you faced similar issues? Let’s discuss how you’ve handled them in the comments! 🚀

#Linux #Troubleshooting #Ubuntu #DevOps #SRE