100187cb80
/users/bruno (and any route that imports demo-bot.server.ts) was returning 500 on prod after #258 because the route's module graph loaded metrics.server.ts a second time, re-running collectDefaultMetrics and `new client.Gauge(...)` — prom-client's global registry rejects duplicate metric names, so the route module failed to load. Guard every metric creation via `getSingleMetric` so a second module load reuses the existing gauges/histograms. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
51 lines
1.7 KiB
TypeScript
51 lines
1.7 KiB
TypeScript
import client from "prom-client";
|
|
|
|
// React Router's build sometimes produces two module instances of this
|
|
// file (server entry + route module graph). prom-client's registry is a
|
|
// process-wide singleton, so re-running the `new Gauge(...)` / `new
|
|
// Histogram(...)` / `collectDefaultMetrics()` calls on the second load
|
|
// throws "metric already registered". Guard everything via
|
|
// `getSingleMetric` so a second module load reuses the existing objects.
|
|
|
|
function getOrCreate<T extends client.Metric<string>>(
|
|
name: string,
|
|
create: () => T,
|
|
): T {
|
|
const existing = client.register.getSingleMetric(name);
|
|
if (existing) return existing as T;
|
|
return create();
|
|
}
|
|
|
|
// Default process/Node metrics: registered exactly once.
|
|
if (!client.register.getSingleMetric("process_cpu_user_seconds_total")) {
|
|
client.collectDefaultMetrics();
|
|
}
|
|
|
|
export const httpRequestDuration = getOrCreate("http_request_duration_seconds", () =>
|
|
new client.Histogram({
|
|
name: "http_request_duration_seconds",
|
|
help: "Duration of HTTP requests in seconds",
|
|
labelNames: ["method", "route", "status"] as const,
|
|
buckets: [0.01, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5],
|
|
}),
|
|
);
|
|
|
|
export const demoBotSyntheticRoutesTotal = getOrCreate(
|
|
"demo_bot_synthetic_routes_total",
|
|
() =>
|
|
new client.Gauge({
|
|
name: "demo_bot_synthetic_routes_total",
|
|
help: "Total synthetic demo-bot routes currently stored",
|
|
}),
|
|
);
|
|
|
|
export const demoBotSyntheticActivitiesTotal = getOrCreate(
|
|
"demo_bot_synthetic_activities_total",
|
|
() =>
|
|
new client.Gauge({
|
|
name: "demo_bot_synthetic_activities_total",
|
|
help: "Total synthetic demo-bot activities currently stored",
|
|
}),
|
|
);
|
|
|
|
export const registry = client.register;
|