Merge pull request #247 from blockfrost/chore/health-check-interval

chore: control metric/healthcheck interval with env METRICS_COLLECTOR…

README.md

@@ -51,6 +51,7 @@ Optional configuration:
 
 - `BLOCKFROST_BACKEND_URL` URL pointing to your own backend (blockfrost-backend-ryo) if you prefer not to use the public Blockfrost API
 - `BLOCKFROST_BLOCK_LISTEN_INTERVAL` how often should be the server pulling the backend for new data (in milliseconds, default `5000`)
+- `METRICS_COLLECTOR_INTERVAL_MS` frequency for refreshing metrics and performing health check (default `10000`)
 - `PORT` which port the server should listen to (default `3005`)
 
 Once your server has started, you can connect to it.

src/constants/config.ts

@@ -22,7 +22,9 @@ export const FIAT_RATES_ENABLE_ON_TESTNET = false;
 export const BLOCKFROST_REQUEST_CONCURRENCY = 500;
 
 // How often should metrics be updated
-export const METRICS_COLLECTOR_INTERVAL_MS = 10_000;
+export const METRICS_COLLECTOR_INTERVAL_MS = Number(
+  process.env.METRICS_COLLECTOR_INTERVAL_MS ?? 10_000,
+);
 
 // If healthcheck repeatedly fails for duration longer than this constant the process exits
 export const HEALTHCHECK_FAIL_THRESHOLD_MS = 6 * METRICS_COLLECTOR_INTERVAL_MS; // 6 health checks

src/utils/prometheus.ts

@@ -42,7 +42,7 @@ export class MetricsCollector {
       if (this.healthCheckFailingSince) {
         const failDurationMs = Date.now() - this.healthCheckFailingSince;
 
-        if (failDurationMs > HEALTHCHECK_FAIL_THRESHOLD_MS) {
+        if (HEALTHCHECK_FAIL_THRESHOLD_MS > 0 && failDurationMs > HEALTHCHECK_FAIL_THRESHOLD_MS) {
           logger.error(
             `Healthcheck failing for longer than ${HEALTHCHECK_FAIL_THRESHOLD_MS} ms. Exiting process.`,
           );
@@ -79,10 +79,12 @@ export class MetricsCollector {
   };
 
   startCollector = async (interval: number) => {
-    this.metrics = await this._collect();
-    this.intervalId = setInterval(async () => {
+    if (interval > 0) {
       this.metrics = await this._collect();
-    }, interval);
+      this.intervalId = setInterval(async () => {
+        this.metrics = await this._collect();
+      }, interval);
+    }
   };
 
   stopCollector = () => {