Average response time

metric.sh

#!/usr/bin/env bash

# calculate the average response time of the server for a given url received as an argument.

# Number of requests to make
requests=$1

# URL to make requests to
url=$2

# Array to store the process IDs of the background processes
pid_array=()

# Whether to run requests in parallel or not
parallel=true

# Timeout between requests
timeout=0.2

if [ -z "$requests" ] || [ -z "$url" ]; then
    echo "Usage: $0 <number of requests> <url>"
    exit 1
fi

# Temporary file to store response times
tmpfile=$(mktemp)

# make a single request and output response time
request_and_calculate_time() {
    local url=$1
    local response_time=$(curl -s -w "%{time_total}" -o /dev/null "$url")

    echo "$response_time" >>"$tmpfile"
    time_in_ms "$response_time"
}

time_in_ms() {
    echo "$(echo "scale=3; $1 * 1000" | bc) ms"
}

# Iterate through the number of requests and run them
for i in $(seq 1 $requests); do
    if [ "$parallel" = true ]; then
        request_and_calculate_time "$url" &
    else
        request_and_calculate_time "$url"
    fi

    sleep "$timeout"

    pid_array+=($!) # Store the process IDs in an array
done

# Wait for all background processes to finish
for pid in "${pid_array[@]}"; do
    wait $pid
done

# Calculate the average response time
average_time=$(awk '{ total += $1 } END { print total / NR }' "$tmpfile")

# Clean up temporary file
rm "$tmpfile"

# Display the average response time
echo "Average response time: $(time_in_ms $average_time)"