Documentation Index
Fetch the complete documentation index at: https://docs.prism.byescaleira.com/llms.txt
Use this file to discover all available pages before exploring further.
Health Checks
Health checks let load balancers, orchestrators, and monitoring systems know if your server is ready to handle traffic. Prism’s PrismHealthMonitor runs checks on demand and serves results through a /health endpoint.
Quick Setup
let health = PrismHealthMonitor()
await server.use(PrismHealthMiddleware(monitor: health))
// GET /health → {"status": "healthy", "checks": []}
Adding Checks
let health = PrismHealthMonitor()
// Simple status check
await health.register("memory") {
let info = ProcessInfo.processInfo
return info.physicalMemory > 0 ? .healthy : .unhealthy
}
// Detailed check with messages
await health.register(PrismHealthCheck(name: "database") {
do {
try await db.execute("SELECT 1")
return PrismHealthCheckResult(name: "database", status: .healthy, message: "Connected")
} catch {
return PrismHealthCheckResult(name: "database", status: .unhealthy, message: error.localizedDescription)
}
})
await health.register(PrismHealthCheck(name: "disk") {
let free = freeDiskSpace()
if free < 100_000_000 {
return PrismHealthCheckResult(name: "disk", status: .unhealthy, message: "Less than 100MB free")
} else if free < 1_000_000_000 {
return PrismHealthCheckResult(name: "disk", status: .degraded, message: "Less than 1GB free")
}
return PrismHealthCheckResult(name: "disk", status: .healthy)
})
await server.use(PrismHealthMiddleware(monitor: health))
Health Status Levels
| Status | HTTP Code | Meaning |
|---|
.healthy | 200 | Everything is operational |
.degraded | 503 | Running but with issues — may need attention |
.unhealthy | 503 | Not ready to handle traffic |
.unhealthy, the report is unhealthy. If any is .degraded (and none unhealthy), the report is degraded.
{
"status": "degraded",
"checks": [
{"name": "database", "status": "healthy", "message": "Connected"},
{"name": "disk", "status": "degraded", "message": "Less than 1GB free"},
{"name": "memory", "status": "healthy"}
]
}
Custom Endpoint Path
await server.use(PrismHealthMiddleware(monitor: health, path: "/api/health"))
// Now at GET /api/health instead of /health
Programmatic Health Checks
Run checks without the middleware:
let report = await health.checkHealth()
if report.status == .unhealthy {
print("Server is unhealthy!")
for check in report.checks where check.status == .unhealthy {
print(" Failed: \(check.name) — \(check.message ?? "unknown")")
}
}
Kubernetes uses two kinds of probes: liveness (is the process alive?) and readiness (can it handle traffic?). Use /health for readiness probes. For liveness, a simple 200-OK endpoint that doesn’t check dependencies is usually enough.
Each check’s execution time is measured automatically. This helps identify slow dependencies — a database check that takes 5 seconds is a red flag even if it returns healthy.
