#####   ######  #####    ###    #   #  ###  #   #  ######
##  ##  ##      ##  ##  ## ##   #   #   #   #   #  ##
#####   ####    #####   #   #   #   #   #   #   #  ####
##  #   ##      ##      ## ##    # #    #    # #   ##
##   #  ######  ##       ###      #    ###    #    ######

$ curl repovive.com/roadmaps/system-design-interview-prep/reliability-fault-tolerance/health-checks-and-heartbeats

░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░██████████████████████████████████████████████████████████████████████████████████████████████████████████████████

#####   ######  #####    ###    #   #  ###  #   #  ######
##  ##  ##      ##  ##  ## ##   #   #   #   #   #  ##
#####   ####    #####   #   #   #   #   #   #   #  ####
##  #   ##      ##      ## ##    # #    #    # #   ##
##   #  ######  ##       ###      #    ###    #    ######

$ curl repovive.com/roadmaps/system-design-interview-prep/reliability-fault-tolerance/health-checks-and-heartbeats

Repovive

Health Checks and Heartbeats - Reliability & Fault Tolerance | System Design Interview Prep | Repovive

Repovive.

System Design Interview Prep22 sections · 691 units23h total

Open in Course

Health Checks and Heartbeats

Detecting failures

Services must report their health:

Liveness checks: Is the process running? Kubernetes restarts if liveness fails.

Readiness checks: Can the service handle requests? Load balancer removes unready instances.

Deep health checks: Verify dependencies. Database connection? Cache reachable? Use sparingly to avoid cascading failures.

Implementation:

GET /health
{ "status": "healthy", "db": "ok", "cache": "ok" }

Heartbeats: Services periodically report to coordinator. Missing heartbeats trigger failover.