- bump to 1.0.10

- Use gc-stats to calculate when to make a OoM heapdumo instead of process.memoryUsage() as this memory information (heapTotal) is growing over time, which is not what was expected while developing.
- Stringify gc-stats output, so it runs over only 1 line.

Author: paulrutter

CHANGELOG.md

@@ -1,3 +1,7 @@
+11-17-2017 - Paul Rütter
+- 1.0.10 - Use gc-stats to calculate when to make a OoM heapdumo instead of process.memoryUsage() as this memory information (heapTotal) is growing over time, which is not expected.
+- Stringify gc-stats output, so it runs over only 1 line.
+
 06-10-2017 - Paul Rütter
 - 1.0.9 - Handle exit codes better and reject promise if so.
 

README.md

@@ -6,13 +6,13 @@ It can also create heapdumps and CPU profiles on request like 'v8-profiler', but
 Tested on Node.js 8.x, but should also work fine using Node.js 6.3 upwards (According to: https://chromedevtools.github.io/devtools-protocol/v8/).
 
 # Why?
-When running nodejs processes in a low memory environment, every out of memory that occurs is interesting. 
+When running nodejs processes in a low memory environment, every out of memory that occurs is interesting.
 To figure out why a process went out of memory, a heap snapshot (e.g. heapdump) can help a lot.
 This module creates a heap snapshot right before a suspected out of memory error occurs.
 It shows what the heap was filled with right before the out of memory error occured.
 
 There are several modules around which can create heapdumps (v8-profiler, node-heapdump), but these run in the same process as the one going out of memory. Often, creating heapdump won't work when the node process is already struggling.
-This module creates the heap snapshot from a separate process, which solves this issue.  
+This module creates the heap snapshot from a separate process, which solves this issue.
 
 # What?
 It uses 'gc-stats' to determine when an out of memory error is about to occur and then fires up a new process which uses 'chrome-remote-interface' to connect with the DevTools protocol (https://chromedevtools.github.io/devtools-protocol/v8/) of the calling process. That process uses HeapProfiler to actually create the heapdump and then exits.
@@ -31,7 +31,7 @@ Just add the following snippet to your node process.
 ```javascript
 let path = require('path');
 require('node-oom-heapdump')({
-    threshold: 90,
+    threshold: 70,
     path: path.resolve(__dirname, 'my_heapdump')
 });
 ```
@@ -48,7 +48,7 @@ These might impact performance though.
 
 # Options
 * heapdumpOnOOM - boolean whether to create a heapdump when an out of memory occurs. Default true.
-* threshold - integer between 0 and 100 (%) which determines when to make the heapdump. When the used heapSize exceeds the threshold, a heapdump is made. This value can be tuned depending on your configuration; if memory usage is very volatile, a lower value might make more sense. Default is 90.
+* threshold - integer between 0 and 100 (%) which determines when to make the heapdump. When the used heapSize exceeds the threshold, a heapdump is made. This value can be tuned depending on your configuration; if memory usage is very volatile, a lower value might make more sense. Default is 70.
 * path - the path where the heapdump ends up when an out of memory error occurs. '.heapsnapshot' is automatically appended. Defaults to this modules' directory.
 * addTimestamp - add a timestamp to the out of memory heapdump filename, to make it unique. Default is false.
 * limit - optionally, specify a limit to how many heapdumps will be created when being above the threshold. Default is 3.
@@ -71,7 +71,7 @@ let nodeOomHeapdump = require("node-oom-heapdump")({
   */
 nodeOomHeapdump.createHeapSnapshot("myheapsnapshotpath").then((snapshotPath) => {
   // do something with heap snapshot
-  
+
   // and delete again from disk
   nodeOomHeapdump.deleteHeapSnapshot(snapshotPath);
 }).catch((err) => {
@@ -85,7 +85,7 @@ nodeOomHeapdump.deleteAllHeapSnapshots();
 
 /**
   * Deletes a particular snapshot from disk
-  * @param {String} snapshotPath - path of the heap snapshot to delete 
+  * @param {String} snapshotPath - path of the heap snapshot to delete
   * @return {Promise}
   */
 nodeOomHeapdump.deleteHeapSnapshot(snapshotPath);
@@ -98,7 +98,7 @@ nodeOomHeapdump.deleteHeapSnapshot(snapshotPath);
   */
 nodeOomHeapdump.createCpuProfile("mycpuprofilepath", 10000).then((cpuProfilePath) => {
   // do something with CPU profile
-  
+
   // and delete again from disk
   nodeOomHeapdump.deleteCpuProfile(cpuProfilePath);
 }).catch((err) => {

index.js

@@ -37,7 +37,7 @@ class NodeOomHeapdumpAPI {
 
   /**
    * Deletes a particular snapshot from disk
-   * @param {String} snapshotPath - path of the heap snapshot to delete 
+   * @param {String} snapshotPath - path of the heap snapshot to delete
    * @return {Promise}
    */
   deleteHeapSnapshot(snapshotPath) {
@@ -82,7 +82,7 @@ function parseOptions(options) {
     options.heapdumpOnOOM = true;
   }
   if (options.threshold === undefined) {
-    options.threshold = 90;
+    options.threshold = 70;
   } else {
     options.threshold = parseInt(options.threshold);
   }

lib/cpuProfileWorker.js

@@ -20,7 +20,7 @@ writeStream.on('error', (err) => {
 
 CDP({
     host: 'localhost',
-    port: devToolsPort,
+    port: devToolsPort
 }, (debugInstance) => {
     let cpuProfiler = debugInstance.Profiler;
     cpuProfiler.enable();

lib/heapdumpWorker.js

@@ -20,7 +20,7 @@ writeStream.on('error', (err) => {
 
 CDP({
     host: 'localhost',
-    port: devToolsPort,
+    port: devToolsPort
 }, (debugInstance) => {
     debugInstance.Debugger.enable();
     debugInstance.Debugger.pause();
@@ -32,7 +32,7 @@ CDP({
         writeStream.write(evt.chunk);
     });
     heapProfiler.takeHeapSnapshot({
-        reportProgress: false,
+        reportProgress: false
     }, function () {
         heapProfiler.disable();
         writeStream.end();

lib/index.js

@@ -21,12 +21,11 @@ class NodeOomHeapDumpImpl {
     gcStats.on('stats', (stats) => {
       // gctype 2 is a Full GC (Mark/Sweep/Compact)
       if (stats.gctype === 2 && !this._busy) {
-        let memoryUsage = process.memoryUsage();
-        var memoryUsagePercentage = Math.round((memoryUsage.heapUsed / memoryUsage.heapTotal) * 100);
+        let memoryUsagePercentage = Math.round((stats.after.usedHeapSize / stats.after.heapSizeLimit) * 100);
         if (memoryUsagePercentage > this._opts.threshold) {
           if (this._count < this._opts.limit) {
             // this is a full GC and the used heap size is using more than x% of the assigned heap space limit
-            console.warn('OoM is imminent: Full GC (Mark/Sweep/Compact) complete and still more than %s% (%s%) of the heap is used. Creating heapdump now. GC stats: ', this._opts.threshold, Math.round(memoryUsagePercentage), stats);
+            console.warn('OoM is imminent: Full GC (Mark/Sweep/Compact) complete and still more than %s% (%s%) of the heap is used. Creating heapdump now. GC stats: ', this._opts.threshold, Math.round(memoryUsagePercentage), JSON.stringify(stats));
 
             this.createHeapSnapshot(this._opts.path, "OoM");
 
@@ -158,7 +157,7 @@ class NodeOomHeapDumpImpl {
 
   /**
    * Deletes a particular snapshot from disk
-   * @param {String} snapshotPath - path of the heap snapshot to delete 
+   * @param {String} snapshotPath - path of the heap snapshot to delete
    * @return {Promise}
    */
   deleteHeapSnapshot(snapshotPath) {
@@ -178,7 +177,7 @@ class NodeOomHeapDumpImpl {
 
   /**
    * Deletes a particular CPU profile from disk
-   * @param {String} cpuProfilePath - path of the CPU profile to delete 
+   * @param {String} cpuProfilePath - path of the CPU profile to delete
    * @return {Promise}
    */
   deleteCpuProfile(cpuProfilePath) {
@@ -187,7 +186,7 @@ class NodeOomHeapDumpImpl {
 
   /**
    * Deletes a given CPU profile or heapsnapshot  from disk
-   * @param {String} path - path to the file to delete 
+   * @param {String} path - path to the file to delete
    * @return {Promise}
    */
   _deleteFile(path) {

package.json

@@ -1,10 +1,10 @@
 {
   "name": "node-oom-heapdump",
-  "version": "1.0.9",
+  "version": "1.0.10",
   "description": "Create a V8 heap snapshot right before an \"Out of Memory\" error occurs, or create a heap snapshot on request.",
   "main": "index.js",
   "scripts": {
-    "test": "node --max_old_space_size=60 --optimize_for_size --always_compact --inspect tests\\oom_app.js"
+    "test": "node --max_old_space_size=80 --optimize_for_size --always_compact --inspect tests\\oom_app.js"
   },
   "repository": {
     "type": "git",

tests/oom_app.js

@@ -1,10 +1,10 @@
 let path = require('path');
- 
+
 let oom = require("../index.js")({
-    threshold: 90,
+    threshold: 70,
     path: path.resolve(__dirname, 'my_heapdump'),
     heapdumpOnOOM: true,
-    limit: 2,
+    limit: 1,
     addTimestamp: false
 });