How can you determine which processes use the most resources on your system?

1 Why monitor processes?

Monitoring processes is essential for diagnosing and resolving performance issues, such as high load, slow response, or resource exhaustion. By tracking the resource consumption of your processes, you can identify the ones that are causing problems, optimize their settings, or terminate them if necessary. Monitoring processes also helps you to plan and allocate resources for your system, such as upgrading hardware, adding more memory, or scaling up or down.

2 What tools to use?

There are many tools and commands that you can use to monitor and manage processes on your system, depending on your operating system and preferences. Some of the most popular and widely available ones are:

- top : a command-line tool that shows the real-time information of your processes, such as CPU, memory, and disk usage, process ID, user, command, priority, and state. You can sort, filter, and kill processes using top .

- ps : a command-line tool that shows information about the processes that are currently running on your system. You can use various options and filters to customize the output of ps .

- htop : an interactive and enhanced version of top that provides a more user-friendly and colorful interface. You can use htop to view, sort, search, and kill processes using your keyboard or mouse.

- glances : a cross-platform and comprehensive tool that shows the system-wide and per-process information, such as CPU, memory, disk, network, sensors, file system, and process tree. You can use glances to monitor and manage processes in various modes, such as web, terminal, or client-server.

- Task Manager (Windows) or Activity Monitor (macOS): graphical tools that show the information and statistics of your processes, such as CPU, memory, disk, network, and energy usage. You can use these tools to view, sort, filter, and end processes using your mouse.

3 How to analyze processes?

To analyze the resource usage of your processes, you need to utilize the mentioned tools and commands to collect and compare the data. It's important to pay attention to metrics such as CPU usage, memory usage, disk usage, and network usage. CPU usage can be seen with the %CPU column in top , ps , htop , or glances . Memory usage can be determined with the %MEM or RES column in the same tools. To observe disk usage, use the DISK READ or DISK WRITE column in glances , or the Disk tab in Task Manager or Activity Monitor. Finally, network usage can be monitored with the NET RX or NET TX column in glances , or the Network tab in Task Manager or Activity Monitor. A high resource usage indicates that a process is performing intensive calculations, storing data in memory, transferring data on disk, or communicating over the network - all of which are important to note for understanding your processes better.

4 How to manage processes?

To manage the resource usage of your processes, you can use a variety of tools and commands to adjust or terminate them. For example, you can change the priority of a process with the nice or renice commands, or by using the P key in top or htop . Additionally, you can change the affinity of a process with the taskset command or the A key in htop . The limit of a process can be changed with the ulimit command or by using the cgroups feature. To kill a process, you can use the kill , pkill , or k keys in various programs, as well as the buttons in Task Manager or Activity Monitor.

5 How to automate processes?

To automate the monitoring and management of your processes, you can use scripts, schedulers, or tools that can perform actions based on rules or thresholds. Some of the examples are:

- cron : a scheduler that can execute commands or scripts at specified times or intervals. You can use cron to run top , ps , htop , or glances periodically and save the output to a file or send it to an email.

- pidstat : a command-line tool that can report the resource usage of processes over time. You can use pidstat to collect and analyze the data of your processes and generate graphs or charts.

- monit : a tool that can monitor and manage processes based on rules or thresholds. You can use monit to check the status, resource usage, or output of your processes and perform actions, such as restarting, stopping, or notifying, if they fail or exceed the limits.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?