Digtest for diagnosing DNS timings

digtest.sh

#!/bin/bash
# depends on gawk
# if running in a netshoot container, you need to install it:
# apk add --no-cache gawk

# Filename to store the results
output_file="dig_results.txt"
times_file="query_times.txt"

# Clear files if they already exist
> "$output_file"
> "$times_file"

# Number of iterations
iterations=1000
echo "Performing $iterations DNS lookups..."

# Execute dig command multiple times and save the query times
for i in $(seq 1 $iterations); do
    dig bitcoind-mutinynet.bitcoind.svc.cluster.local | grep "Query time" >> "$output_file"
done

# Extract the query times from the results
awk -F ": " '/Query time/ {print $2}' "$output_file" | awk '{print $1}' > "$times_file"

# Calculate percentile distributions using gawk instead of awk
echo "Calculating percentile distributions..."
gawk 'BEGIN {
    total = 0;
    count = 0;
    data[0] = 0;
}
{
    data[count++] = $1;
    total += $1;
}
END {
    asort(data);
    p50 = int(0.5 * count);
    p90 = int(0.9 * count);
    p95 = int(0.95 * count);
    p99 = int(0.99 * count);
    print "50th Percentile (Median): " data[p50] " ms";
    print "90th Percentile: " data[p90] " ms";
    print "95th Percentile: " data[p95] " ms";
    print "99th Percentile: " data[p99] " ms";
    print "Average: " total/count " ms";
}' "$times_file"