API Health Checks
API health checks are lightweight endpoints or probes that report whether a service is functioning. Monitors, load balancers, and gateways call them regularly, and unhealthy responses trigger alerts, traffic rerouting, or automated recovery.
Technical Architecture & Deep-Dive
A liveness check confirms the process is running, while a readiness check confirms it can serve traffic, including connectivity to databases or critical dependencies.
Health checks should be fast and avoid expensive operations. For third-party dependencies, passive health signals such as recent error rates observed by the gateway are often more reliable than active probes.
Key Architectural Benefits
Implement API Health Checks at the Edge
Deploy lightweight API aggregation, edge caching, and secret injection in minutes without Docker containers or complex servers.
Frequently Asked Questions
Q:Should health checks call downstream APIs?
Readiness checks may verify critical dependencies, but avoid chaining slow or rate-limited calls. Cache dependency status briefly to prevent load.
Related Architecture Concepts
API failover is automatically redirecting traffic from a failing primary service to a healthy backup, such as a secondary region, an alternative provider, or a cached response. Failover keeps applications available when a dependency experiences an outage.
The Circuit Breaker pattern is a software resiliency design that monitors upstream service health and temporarily halts requests to failing endpoints. By failing fast and returning cached fallback data, it prevents cascading system outages and reduces recovery time.
P99 latency is the response time below which 99 percent of requests complete, so only the slowest 1 percent take longer. Percentile metrics like p50, p95, and p99 reveal tail latency, the slow outliers that averages hide but users still experience.