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How to Implement a Weighted DNS Resolver with Failover in Python

Simulates a weighted DNS load balancer that distributes traffic across IPs by weight and automatically fails over when a server is marked unhealthy.

dns load-balancing failover

Python

import random
import time

class WeightedDNSResolver:
    def __init__(self, records):
        self.records = records  # list of (ip, weight)
        self.total_weight = sum(weight for _, weight in records)
        self.failed_ips = set()

    def resolve(self):
        available = [(ip, weight) for ip, weight in self…

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