```yaml
product: AlterLab
title: "Load Balancer — Web Scraping Glossary | AlterLab"
comparison_context: "AlterLab is an alternative to Firecrawl, ScrapingBee, and Bright Data."
source_url: https://alterlab.io/glossary/load-balancer
```

infrastructure

# Load Balancer

A load balancer distributes incoming requests across multiple servers to prevent any single server from becoming a bottleneck and to provide high availability.

Load balancers sit in front of a pool of backend servers and forward each incoming request to one of them based on an algorithm: round-robin (sequentially cycles through backends), least-connections (sends to the backend with the fewest active connections), IP-hash (always routes the same client IP to the same backend for session stickiness), or weighted round-robin (favours higher-capacity backends).

For scraping platforms, load balancers distribute API requests across multiple API server instances, distribute scraping jobs across worker pools, and route browser sessions to available browser farms. Health checks ensure that failed backends are removed from rotation automatically.

From a scraping target's perspective, a load balancer means that consecutive requests from the same IP may reach different backend servers, which can affect session-based anti-bot systems that store state on individual servers. Sticky-session load balancers address this by ensuring a given IP or cookie always routes to the same backend.

### What is Load Balancer?

A load balancer distributes incoming requests across multiple servers to prevent any single server from becoming a bottleneck and to provide high availability.

### How does AlterLab handle Load Balancer?

From a scraping target's perspective, a load balancer means that consecutive requests from the same IP may reach different backend servers, which can affect session-based anti-bot systems that store state on individual servers. Sticky-session load balancers address this by ensuring a given IP or cookie always routes to the same backend.

## Related Terms

[Proxy PoolA managed collection of proxy IP addresses used to distribute outbound requests across multiple origins and stay below per-IP rate limits.](https://alterlab.io/glossary/proxy-pool)[Rate LimitingA server-side control that caps the number of requests accepted from a single IP or session within a time window, returning HTTP 429 when exceeded.](https://alterlab.io/glossary/rate-limiting)[ConcurrencyConcurrency in scraping refers to the number of requests or browser sessions running in parallel, which directly controls throughput and resource consumption.](https://alterlab.io/glossary/concurrency)[API GatewayAn API gateway is a reverse proxy that sits in front of backend services, handling authentication, rate limiting, routing, and protocol translation for incoming API requests.](https://alterlab.io/glossary/api-gateway)[Content Delivery Network (CDN)A distributed network of servers that delivers web content from locations geographically close to the user, often where anti-bot protection is deployed.](https://alterlab.io/glossary/content-delivery-network)

## Extract Load Balancer data from any website

AlterLab returns clean, structured data from any public URL — no scraper infrastructure needed. Start free, no credit card required.

[View API docs](https://alterlab.io/docs/api/rest)

[Back to Glossary](https://alterlab.io/glossary)