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$ curl repovive.com/roadmaps/network-design/load-balancing/least-connections-algorithm

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$ curl repovive.com/roadmaps/network-design/load-balancing/least-connections-algorithm

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Least Connections Algorithm - Load Balancing | Network Design | Repovive

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Network Design26 sections · 911 units44h total

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Least Connections Algorithm

Load-aware distribution

Least connections sends each new request to the server currently handling the fewest active connections.

The algorithm tracks connection counts per server. When a new request arrives, it scans for the minimum. This takes $O(n)$ time where $n$ is the server count. Space is $O(n)$ for counters.

function leastConnections(servers):
    minConnections = infinity
    selected = null
    for server in servers:
        if server.connections < minConnections:
            minConnections = server.connections
            selected = server
    return selected

This adapts better than round-robin when requests have varying processing times.