update

package.json

@@ -17,7 +17,8 @@
     "@git.zone/tsbundle": "^2.8.3",
     "@git.zone/tsrun": "^2.0.1",
     "@git.zone/tstest": "^3.1.8",
-    "@types/node": "^25.3.0"
+    "@types/node": "^25.3.0",
+    "@types/pidusage": "^2.0.2"
   },
   "browserslist": [
     "last 1 chrome versions"
@@ -37,7 +38,6 @@
   "dependencies": {
     "@push.rocks/smartdelay": "^3.0.5",
     "@push.rocks/smartlog": "^3.1.11",
-    "@types/pidusage": "^2.0.2",
     "pidtree": "^0.6.0",
     "pidusage": "^4.0.1",
     "prom-client": "^15.1.3"

pnpm-lock.yaml

@@ -14,9 +14,6 @@ importers:
       '@push.rocks/smartlog':
         specifier: ^3.1.11
         version: 3.1.11
-      '@types/pidusage':
-        specifier: ^2.0.2
-        version: 2.0.5
       pidtree:
         specifier: ^0.6.0
         version: 0.6.0
@@ -42,6 +39,9 @@ importers:
       '@types/node':
         specifier: ^25.3.0
         version: 25.3.0
+      '@types/pidusage':
+        specifier: ^2.0.2
+        version: 2.0.5
 
 packages:
 

readme.md

@@ -71,7 +71,7 @@ SmartMetrics doesn't just monitor your main process – it automatically discove
 The library automatically detects available memory whether running on bare metal, in Docker containers, or with Node.js heap restrictions. It picks the most restrictive of:
 
 1. **System total memory** (`os.totalmem()`)
-2. **Docker cgroup limit** (`/sys/fs/cgroup/memory/memory.limit_in_bytes`)
+2. **Docker cgroup limit** – supports both cgroup v2 (`/sys/fs/cgroup/memory.max`) and cgroup v1 (`/sys/fs/cgroup/memory/memory.limit_in_bytes`)
 3. **V8 heap size limit** (`v8.getHeapStatistics().heap_size_limit`)
 
 This ensures accurate percentage calculations regardless of environment.
@@ -101,8 +101,8 @@ Retrieves current system metrics as a structured object.
 ```typescript
 {
   process_cpu_seconds_total: number;    // Total CPU time in seconds
-  nodejs_active_handles_total: number;   // Active handles count
+  nodejs_active_handles_total: number;   // Always 0 (deprecated Node.js API; real values tracked by Prometheus default collectors)
-  nodejs_active_requests_total: number;  // Active requests count
+  nodejs_active_requests_total: number;  // Always 0 (deprecated Node.js API; real values tracked by Prometheus default collectors)
   nodejs_heap_size_total_bytes: number;  // V8 heap size in bytes
   cpuPercentage: number;                 // Aggregated CPU usage across all child processes
   cpuUsageText: string;                  // Human-readable CPU usage (e.g. "12.5 %")

test/test.ts

@@ -75,4 +75,4 @@ tap.test('should disable Prometheus endpoint', async () => {
   }
 });
 
-tap.start();
+export default tap.start();

ts/smartmetrics.classes.smartmetrics.ts

@@ -17,7 +17,7 @@ export class SmartMetrics {
   private prometheusServer?: plugins.http.Server;
   private prometheusPort?: number;
 
-  public async setup() {
+  public setup() {
     const collectDefaultMetrics = plugins.promClient.collectDefaultMetrics;
     this.registry = new plugins.promClient.Registry();
     collectDefaultMetrics({ register: this.registry });
@@ -50,28 +50,32 @@ export class SmartMetrics {
   }
 
   private checkMemoryLimits() {
-    let heapStats = plugins.v8.getHeapStatistics();
+    const heapStats = plugins.v8.getHeapStatistics();
-    let maxHeapSizeMB = heapStats.heap_size_limit / 1024 / 1024;
+    const maxHeapSizeMB = heapStats.heap_size_limit / 1024 / 1024;
-    let totalSystemMemoryMB = plugins.os.totalmem() / 1024 / 1024;
+    const totalSystemMemoryMB = plugins.os.totalmem() / 1024 / 1024;
 
     let dockerMemoryLimitMB = totalSystemMemoryMB;
+
+    // Try cgroup v2 first, then fall back to cgroup v1
     try {
-      let dockerMemoryLimitBytes = plugins.fs.readFileSync(
+      const cgroupV2 = plugins.fs.readFileSync('/sys/fs/cgroup/memory.max', 'utf8').trim();
-        '/sys/fs/cgroup/memory/memory.limit_in_bytes',
+      if (cgroupV2 !== 'max') {
-        'utf8'
+        dockerMemoryLimitMB = parseInt(cgroupV2, 10) / 1024 / 1024;
-      );
+      }
-      dockerMemoryLimitMB = parseInt(dockerMemoryLimitBytes, 10) / 1024 / 1024;
+    } catch {
-    } catch (error) {
+      try {
-      // Ignore - this will fail if not running in a Docker container
+        const cgroupV1 = plugins.fs.readFileSync(
+          '/sys/fs/cgroup/memory/memory.limit_in_bytes',
+          'utf8'
+        ).trim();
+        dockerMemoryLimitMB = parseInt(cgroupV1, 10) / 1024 / 1024;
+      } catch {
+        // Not running in a container — use system memory
+      }
     }
 
-    // Set the maximum memory to the lower value between the Docker limit and the total system memory
+    // Pick the most restrictive limit
     this.maxMemoryMB = Math.min(totalSystemMemoryMB, dockerMemoryLimitMB, maxHeapSizeMB);
-
-    // If the maximum old space size limit is greater than the maximum available memory, throw an error
-    if (maxHeapSizeMB > this.maxMemoryMB) {
-      throw new Error('Node.js process can use more memory than is available');
-    }
   }
 
   public start() {
@@ -104,7 +108,12 @@ export class SmartMetrics {
   }
 
   public async getMetrics() {
-    const pids = await plugins.pidtree(process.pid);
+    let pids: number[] = [];
+    try {
+      pids = await plugins.pidtree(process.pid);
+    } catch {
+      // pidtree can fail if process tree cannot be read
+    }
     const stats = await plugins.pidusage([process.pid, ...pids]);
 
     let cpuPercentage = 0;
@@ -126,8 +135,6 @@ export class SmartMetrics {
       memoryUsageBytes
     )} / ${this.formatBytes(this.maxMemoryMB * 1024 * 1024)}`;
 
-    console.log(`${cpuUsageText} ||| ${memoryUsageText} `);
-    
     // Update Prometheus gauges with current values
     if (this.cpuPercentageGauge) {
       this.cpuPercentageGauge.set(cpuPercentage);