Glossary term
What is health check? Meaning for developers
In DevOps
A request a load balancer or DNS service makes on a schedule. Servers that fail it stop receiving traffic.
Learn it properly · DevOpsLesson 12: ALB and Auto Scaling: Scaling to 1000+ Concurrent UsersOne server becomes many. Health checks, target groups, and servers that appear when traffic spikes and vanish when it drops.In System Design
Regularly checking whether an instance works. Example: Load balancer calls /health every 5 seconds.
Learn it properly · System DesignLesson 12: Load Balancers: L4 vs L7 and Balancing AlgorithmsOne address, many servers, and one of them just crashed at 2 AM. How load balancers spread traffic, L4 vs L7, the balancing algorithms and when each wins, and why a “deep” health check can take everything down at once.In Networking for Developers
A small request sent on a timer to a backend to decide whether it should get traffic.
Learn it properly · Networking for DevelopersLesson 6: Load Balancers, Proxies, CDNs and FirewallsLayer 4 and layer 7 balancing, reverse and forward proxies, CDNs, caching at the edge, and firewalls and security groups.