This shell script monitors the server load average and sends an email notification if it exceeds a dynamically calculated threshold based on the number of CPU cores. It also identifies the process with the highest CPU usage. This script can be scheduled to run periodically using a cron job.

monitor_load_average_linux.sh

#/bin/bash

# Get the number of CPU cores
CPU_CORES=$(nproc)

# Calculate the threshold based on CPU cores, 0.7 -> indicates the 70% of CPU usage
THRESHOLD=$(echo "$CPU_CORES * 0.7" | bc -l)

# Email recipient
EMAIL="[email protected]"

# Get the 1-minute load average
LOAD_AVERAGE=$(uptime | awk -F'average:' '{ print $2 }' | awk '{gsub(",", "", $1); print $1}')

# Check if load average exceeds the threshold
if (( $(echo "$LOAD_AVERAGE > $THRESHOLD" | bc -l) )); then
    # Get the process with the highest CPU usage
    TOP_PROCESS=$(ps -eo pid,%cpu,cmd --sort=-%cpu | head -n 10)

    # Send an email notification
    SUBJECT="Server Load High - $LOAD_AVERAGE"
    BODY="The server load average is above the threshold. Load average: $LOAD_AVERAGE\n\nTop process:\n$TOP_PROCESS"
    echo -e "SUBJECT: $SUBJECT \n\nMAIL BODY: $BODY"
fi

• This shell script monitors the server load average and sends an email notification if it exceeds a dynamically calculated threshold based on the number of CPU cores.
• It also identifies the process with the highest CPU usage.
• This script can be scheduled to run periodically using a cron job.

To manually increase the system load average in Linux. Refer this command:

openssl speed -multi $(grep -ci processor /proc/cpuinfo)
or (if nproc is present)
openssl speed -multi $(nproc --all)
OpenSSL is almost always present on nowadays distros, so no extra packages needed.