10. Processes & Monitoring#
In this chapter, you’ll learn to interact with the operating system’s process management and resource monitoring capabilities. You’ll discover how to launch and manage processes, control their execution in foreground and background, and monitor system health by tracking CPU, memory, disk, and network resources. These skills are essential for developing robust automation scripts, debugging performance issues, and building system administration tools. By mastering process management and monitoring, you’ll be able to write scripts that adapt to system conditions and gracefully handle resource constraints.
What You'll Learn
By the end of this chapter, you will be able to:
✓ Launch and manage processes from scripts ✓ Understand process states and lifecycle ✓ Run commands in foreground and background ✓ Monitor system resources (CPU, memory, disk, network) ✓ Gather and analyze system metrics ✓ Work with process IDs and signals ✓ Build monitoring and alerting scripts ✓ Debug performance issues ✓ Implement resource-aware automation
Chapter Map
Section |
Topic |
Key Concepts |
|---|---|---|
1002 |
Process Management |
ps, kill, fg, bg, jobs, wait |
1003 |
System Metrics |
top, free, df, iostat, vmstat |
1004 |
Process Monitoring |
Tracking processes, exit codes, signals |
1005 |
Resource Constraints |
ulimit, nice, CPU/memory management |
1006 |
Lab: Build a Monitor |
Real-world monitoring system |
Why This Matters
Understanding processes and system monitoring enables:
Reliability: Detect and recover from failures automatically
Performance: Identify bottlenecks and resource constraints
Scalability: Monitor multiple systems and alert on issues
Automation: Scripts that adapt to system conditions
DevOps: Essential for infrastructure management
Real-world impact: Automated monitoring can detect issues before they impact users, saving hours of manual troubleshooting.
Prerequisites
You should already understand:
Shell scripting basics (Chapters 5-8)
I/O and pipes (Chapter 9)
Error handling (Chapter 11 recommended, but not required)
System basics (Chapters 1-3)
What You'll Learn
By the end of this chapter, you will be able to:
✓ Launch and manage processes from scripts ✓ Understand process states and lifecycle ✓ Run commands in foreground and background ✓ Monitor system resources (CPU, memory, disk, network) ✓ Gather and analyze system metrics ✓ Work with process IDs and signals ✓ Build monitoring and alerting scripts ✓ Debug performance issues ✓ Implement resource-aware automation
Chapter Map
Section |
Topic |
Key Concepts |
|---|---|---|
1002 |
Process Management |
ps, kill, fg, bg, jobs, wait |
1003 |
System Metrics |
top, free, df, iostat, vmstat |
1004 |
Process Monitoring |
Tracking processes, exit codes, signals |
1005 |
Resource Constraints |
ulimit, nice, CPU/memory management |
1006 |
Lab: Build a Monitor |
Real-world monitoring system |
Why This Matters
Understanding processes and system monitoring enables:
Reliability: Detect and recover from failures automatically
Performance: Identify bottlenecks and resource constraints
Scalability: Monitor multiple systems and alert on issues
Automation: Scripts that adapt to system conditions
DevOps: Essential for infrastructure management
Real-world impact: Automated monitoring can detect issues before they impact users, saving hours of manual troubleshooting.
Prerequisites
You should already understand:
Shell scripting basics (Chapters 5-8)
I/O and pipes (Chapter 9)
Error handling (Chapter 11 recommended, but not required)
System basics (Chapters 1-3)