Load Average Balancer

A utility script to delay the execution of CPU-intensive tasks (like restic backups) until the system load average drops below a specified threshold.

Purpose

This script was created to prevent restic backups from running during periods of high CPU usage. It monitors the system's 15-minute load average and only exits (allowing the backup to proceed) when either:

• The load average falls below a specified threshold
• A maximum delay time is reached

Usage

Shell Version

./load_average_balancer.sh -d <max_delay_seconds> -t <load_threshold>

Python Version

python3 load_average_balancer.py -d <max_delay_seconds> -t <load_threshold>

The Python version provides the same functionality as the shell script but uses Python's psutil library for system monitoring. It may be more portable across different operating systems.

Arguments

• -d <max_delay_seconds>: Maximum time to wait in seconds before allowing the backup to proceed
• -t <load_threshold>: Load average threshold as a fraction of available CPU cores (0-1)
• -h: Display help message

Example

To wait up to 1 hour for the load to drop below 80% of available CPU cores:

./load_average_balancer.sh -d 3600 -t 0.8

Integration with restic

Shell Version

Add this script before your restic backup command:

./load_average_balancer.sh -d 3600 -t 0.8 && restic backup /path/to/backup

Python Version

python3 load_average_balancer.py -d 3600 -t 0.8 && restic backup /path/to/backup

Requirements

Shell Version

• zsh shell
• bc (basic calculator)
• Standard Unix utilities (uptime, nproc)

Python Version

• Python 3.6 or higher
• psutil package (install with pip install psutil)
• Compatible with Linux, macOS, and other Unix-like systems

Exit Codes

• 0: Success (either load dropped below threshold or maximum delay was reached)
• 1: Invalid arguments or usage error