Node.js heap out of memory

Today I ran my script for filesystem indexing to refresh RAID files index and after 4h it crashed with following error:

[md5:]  241613/241627 97.5%  
[md5:]  241614/241627 97.5%  
[md5:]  241625/241627 98.1%
Creating missing list... (79570 files missing)
Creating new files list... (241627 new files)

<--- Last few GCs --->

11629672 ms: Mark-sweep 1174.6 (1426.5) -> 1172.4 (1418.3) MB, 659.9 / 0 ms [allocation failure] [GC in old space requested].
11630371 ms: Mark-sweep 1172.4 (1418.3) -> 1172.4 (1411.3) MB, 698.9 / 0 ms [allocation failure] [GC in old space requested].
11631105 ms: Mark-sweep 1172.4 (1411.3) -> 1172.4 (1389.3) MB, 733.5 / 0 ms [last resort gc].
11631778 ms: Mark-sweep 1172.4 (1389.3) -> 1172.4 (1368.3) MB, 673.6 / 0 ms [last resort gc].


<--- JS stacktrace --->

==== JS stack trace =========================================

Security context: 0x3d1d329c9e59 <JS Object>
1: SparseJoinWithSeparatorJS(aka SparseJoinWithSeparatorJS) [native array.js:~84] [pc=0x3629ef689ad0] (this=0x3d1d32904189 <undefined>,w=0x2b690ce91071 <JS Array[241627]>,L=241627,M=0x3d1d329b4a11 <JS Function ConvertToString (SharedFunctionInfo 0x3d1d3294ef79)>,N=0x7c953bf4d49 <String[4]\: ,\n  >)
2: Join(aka Join) [native array.js:143] [pc=0x3629ef616696] (this=0x3d1d32904189 <undefin...

FATAL ERROR: CALL_AND_RETRY_LAST Allocation failed - JavaScript heap out of memory
 1: node::Abort() [/usr/bin/node]
 2: 0xe2c5fc [/usr/bin/node]
 3: v8::Utils::ReportApiFailure(char const*, char const*) [/usr/bin/node]
 4: v8::internal::V8::FatalProcessOutOfMemory(char const*, bool) [/usr/bin/node]
 5: v8::internal::Factory::NewRawTwoByteString(int, v8::internal::PretenureFlag) [/usr/bin/node]
 6: v8::internal::Runtime_SparseJoinWithSeparator(int, v8::internal::Object**, v8::internal::Isolate*) [/usr/bin/node]
 7: 0x3629ef50961b

Server is equipped with 16gb RAM and 24gb SSD swap. I highly doubt my script exceeded 36gb of memory. At least it shouldn't

Script creates index of files stored as Array of Objects with files metadata (modification dates, permissions, etc, no big data)

Here's full script code: http://pastebin.com/mjaD76c3

I've already experiend weird node issues in the past with this script what forced me eg. split index into multiple files as node was glitching when working on such big files as String. Is there any way to improve nodejs memory management with huge datasets?

If I remember correctly, there is a strict standard limit for the memory usage in V8 of around 1.7 GB, if you do not increase it manually.

In one of our products we followed this solution in our deploy script:

 node --max-old-space-size=4096 yourFile.js

There would also be a new space command but as I read here: a-tour-of-v8-garbage-collection the new space only collects the newly created short-term data and the old space contains all referenced data structures which should be in your case the best option.

If you want to increase the memory usage of the node globally - not only single script, you can export environment variable, like this:
export NODE_OPTIONS=--max_old_space_size=4096

Then you do not need to play with files when running builds like npm run build.

Just in case anyone runs into this in an environment where they cannot set node properties directly (in my case a build tool):

NODE_OPTIONS="--max-old-space-size=4096" node ...

You can set the node options using an environment variable if you cannot pass them on the command line.

Here are some flag values to add some additional info on how to allow more memory when you start up your node server.

1GB - 8GB

#increase to 1gb
node --max-old-space-size=1024 index.js

#increase to 2gb
node --max-old-space-size=2048 index.js 

#increase to 3gb
node --max-old-space-size=3072 index.js

#increase to 4gb
node --max-old-space-size=4096 index.js

#increase to 5gb
node --max-old-space-size=5120 index.js

#increase to 6gb
node --max-old-space-size=6144 index.js

#increase to 7gb
node --max-old-space-size=7168 index.js

#increase to 8gb 
node --max-old-space-size=8192 index.js 

I just faced same problem with my EC2 instance t2.micro which has 1 GB memory.

I resolved the problem by creating swap file using this url and set following environment variable.

export NODE_OPTIONS=--max_old_space_size=4096

Finally the problem has gone.

I hope that would be helpful for future.

i was struggling with this even after setting --max-old-space-size.

Then i realised need to put options --max-old-space-size before the karma script.

also best to specify both syntaxes --max-old-space-size and --max_old_space_size my script for karma :

node --max-old-space-size=8192 --optimize-for-size --max-executable-size=8192  --max_old_space_size=8192 --optimize_for_size --max_executable_size=8192 node_modules/karma/bin/karma start --single-run --max_new_space_size=8192   --prod --aot

reference https://github.com/angular/angular-cli/issues/1652

I encountered this issue when trying to debug with VSCode, so just wanted to add this is how you can add the argument to your debug setup.

You can add it to the runtimeArgs property of your config in launch.json.

See example below.

{
"version": "0.2.0",
"configurations": [{
        "type": "node",
        "request": "launch",
        "name": "Launch Program",
        "program": "${workspaceRoot}\\server.js"
    },
    {
        "type": "node",
        "request": "launch",
        "name": "Launch Training Script",
        "program": "${workspaceRoot}\\training-script.js",
        "runtimeArgs": [
            "--max-old-space-size=4096"
        ]
    }
]}

I had a similar issue while doing AOT angular build. Following commands helped me.

npm install -g increase-memory-limit
increase-memory-limit

Source: https://geeklearning.io/angular-aot-webpack-memory-trick/

I've faced this same problem recently and came across to this thread but my problem was with React App. Below changes in the node start command solved my issues.

Syntax

node --max-old-space-size=<size> path-to/fileName.js

Example

node --max-old-space-size=16000 scripts/build.js

Why size is 16000 in max-old-space-size?

Basically, it varies depends on the allocated memory to that thread and your node settings.

How to verify and give right size?

This is basically stay in our engine v8. below code helps you to understand the Heap Size of your local node v8 engine.

const v8 = require('v8');
const totalHeapSize = v8.getHeapStatistics().total_available_size;
const totalHeapSizeGb = (totalHeapSize / 1024 / 1024 / 1024).toFixed(2);
console.log('totalHeapSizeGb: ', totalHeapSizeGb);

>Steps to fix this issue (In Windows) -

1. Open command prompt and type %appdata% press enter
2. Navigate to %appdata% > npm folder
3. Open or Edit ng.cmd in your favorite editor
4. Add --max_old_space_size=8192 to the IF and ELSE block

Your node.cmd file looks like this after the change:

@IF EXIST "%~dp0\node.exe" (
  "%~dp0\node.exe" "--max_old_space_size=8192" "%~dp0\node_modules\@angular\cli\bin\ng" %*
) ELSE (
  @SETLOCAL
  @SET PATHEXT=%PATHEXT:;.JS;=;%
  node "--max_old_space_size=8192" "%~dp0\node_modules\@angular\cli\bin\ng" %*
)

I just want to add that in some systems, even increasing the node memory limit with --max-old-space-size, it's not enough and there is an OS error like this:

terminate called after throwing an instance of 'std::bad_alloc'
  what():  std::bad_alloc
Aborted (core dumped)

In this case, probably is because you reached the max mmap per process.

You can check the max_map_count by running

sysctl vm.max_map_count

and increas it by running

sysctl -w vm.max_map_count=655300

and fix it to not be reset after a reboot by adding this line

vm.max_map_count=655300

in /etc/sysctl.conf file.

Check here for more info.

A good method to analyse the error is by run the process with strace

strace node --max-old-space-size=128000 my_memory_consuming_process.js

Recently, in one of my project ran into same problem. Tried couple of things which anyone can try as a debugging to identify the root cause:

1. As everyone suggested , increase the memory limit in node by adding this command:

   {
      "scripts":{
         "server":"node --max-old-space-size={size-value} server/index.js"
      }
   }
   

Here size-value i have defined for my application was 1536 (as my kubernetes pod memory was 2 GB limit , request 1.5 GB)

So always define the size-value based on your frontend infrastructure/architecture limit (little lesser than limit)

One strict callout here in the above command, use --max-old-space-size after node command not after the filename server/index.js.

1. If you have ngnix config file then check following things:

   • worker_connections: 16384 (for heavy frontend applications) [nginx default is 512 connections per worker, which is too low for modern applications]

   • use: epoll (efficient method) [nginx supports a variety of connection processing methods]

   • http: add following things to free your worker from getting busy in handling some unwanted task. (client_body_timeout , reset_timeout_connection , client_header_timeout,keepalive_timeout ,send_timeout).

2. Remove all logging/tracking tools like APM , Kafka , UTM tracking, Prerender (SEO) etc middlewares or turn off.

3. Now code level debugging: In your main server file , remove unwanted console.log which is just printing a message.

4. Now check for every server route i.e app.get() , app.post() ... below scenarios:

• data => if(data) res.send(data) // do you really need to wait for data or that api returns something in response which i have to wait for?? , If not then modify like this:

data => res.send(data) // this will not block your thread, apply everywhere where it's needed

• else part: if there is no error coming then simply return res.send({}) , NO console.log here.

• error part: some people define as error or err which creates confusion and mistakes. like this:

  `error => { next(err) } // here err is undefined`
  
   `err => {next(error) } // here error is undefined`
  
   `app.get(API , (re,res) =>{
       error => next(error) // here next is not defined
    })`
  

• remove winston , elastic-epm-node other unused libraries using npx depcheck command.

• In the axios service file , check the methods and logging properly or not like :

    if(successCB) console.log("success") successCB(response.data) // here it's wrong statement, because on success you are just logging and then `successCB` sending  outside the if block which return in failure case also.
  

• Save yourself from using stringify , parse etc on accessive large dataset. (which i can see in your above shown logs too.

5. Last but not least , for every time when your application crashes or pods restarted check the logs. In log specifically look for this section: Security context This will give you why , where and who is the culprit behind the crash.

I will mention 2 types of solution.

My solution : In my case I add this to my environment variables :

export NODE_OPTIONS=--max_old_space_size=20480

But even if I restart my computer it still does not work. My project folder is in d:\ disk. So I remove my project to c:\ disk and it worked.

My team mate's solution : package.json configuration is worked also.

"start": "rimraf ./build && react-scripts --expose-gc --max_old_space_size=4096 start",

For other beginners like me, who didn't find any suitable solution for this error, check the node version installed (x32, x64, x86). I have a 64-bit CPU and I've installed x86 node version, which caused the CALL_AND_RETRY_LAST Allocation failed - JavaScript heap out of memory error.

if you want to change the memory globally for node (windows) go to advanced system settings -> environment variables -> new user variable

variable name = NODE_OPTIONS
variable value = --max-old-space-size=4096

You can also change Window's environment variables with:

 $env:NODE_OPTIONS="--max-old-space-size=8192"

In my case, I upgraded node.js version to latest (version 12.8.0) and it worked like a charm.

Use the option --optimize-for-size. It's going to focus on using less ram.

Unix (Mac OS)

1. Open a terminal and open our .zshrc file using nano like so (this will create one, if one doesn't exist):

   nano ~/.zshrc

2. Update our NODE_OPTIONS environment variable by adding the following line into our currently open .zshrc file:

   export NODE_OPTIONS=--max-old-space-size=8192 # increase node memory limit

Please note that we can set the number of megabytes passed in to whatever we like, provided our system has enough memory (here we are passing in 8192 megabytes which is roughly 8 GB).

3. Save and exit nano by pressing: ctrl + x, then y to agree and finally enter to save the changes.

4. Close and reopen the terminal to make sure our changes have been recognised.

5. We can print out the contents of our .zshrc file to see if our changes were saved like so: cat ~/.zshrc.

Linux (Ubuntu)

1. Open a terminal and open the .bashrc file using nano like so:

   nano ~/.bashrc

The remaining steps are similar with the Mac steps from above, except we would most likely be using ~/.bashrc by default (as opposed to ~/.zshrc). So these values would need to be substituted!

Link to Nodejs Docs

Upgrade node to the latest version. I was on node 6.6 with this error and upgraded to 8.9.4 and the problem went away.

I had this error on AWS Elastic Beanstalk, upgrading instance type from t3.micro (Free tier) to t3.small fixed the error

I experienced the same problem today. The problem for me was, I was trying to import lot of data to the database in my NextJS project.

So what I did is, I installed win-node-env package like this:

yarn add win-node-env

Because my development machine was Windows. I installed it locally than globally. You can install it globally also like this: yarn global add win-node-env

And then in the package.json file of my NextJS project, I added another startup script like this:

"dev_more_mem": "NODE_OPTIONS=\"--max_old_space_size=8192\" next dev"

Here, am passing the node option, ie. setting 8GB as the limit. So my package.json file somewhat looks like this:

{
  "name": "my_project_name_here",
  "version": "1.0.0",
  "private": true,
  "scripts": {
    "dev": "next dev",
    "dev_more_mem": "NODE_OPTIONS=\"--max_old_space_size=8192\" next dev",
    "build": "next build",
    "lint": "next lint"
  },
  ......
}

And then I run it like this:

yarn dev_more_mem

For me, I was facing the issue only on my development machine (because I was doing the importing of large data). Hence this solution. Thought to share this as it might come in handy for others.

Just in case it may help people having this issue while using nodejs apps that produce heavy logging, a colleague solved this issue by piping the standard output(s) to a file.

If you are trying to launch not node itself, but some other soft, for example webpack you can use the environment variable and cross-env package:

$ cross-env NODE_OPTIONS='--max-old-space-size=4096' \
  webpack --progress --config build/webpack.config.dev.js

For angular project bundling, I've added the below line to my pakage.json file in the scripts section.

"build-prod": "node --max_old_space_size=5120 ./node_modules/@angular/cli/bin/ng build --prod --base-href /"

Now, to bundle my code, I use npm run build-prod instead of ng build --requiredFlagsHere

hope this helps!

For Angular, this is how I fixed

In Package.json, inside script tag add this

"scripts": {
  "build-prod": "node --max_old_space_size=5048 ./node_modules/@angular/cli/bin/ng build --prod",
},

Now in terminal/cmd instead of using ng build --prod just use

npm run build-prod

If you want to use this configuration for build only just remove --prod from all the 3 places

If any of the given answers are not working for you, check your installed node if it compatible (i.e 32bit or 64bit) to your system. Usually this type of error occurs because of incompatible node and OS versions and terminal/system will not tell you about that but will keep you giving out of memory error.

In my case I had ran npm install on previous version of node, after some day I upgraded node version and ram npm install for few modules. After this I was getting this error. To fix this problem I deleted node_module folder from each project and ran npm install again.

Hope this might fix the problem.

Note : This was happening on my local machine and it got fixed on local machine only.

If you have limited memory or RAM, then go for the following command.

> ng serve --source-map=false

It will be able to launch the application. For my example, it needs 16gb RAM. But I can run with 8gb RAM.

Check that you did not install the 32-bit version of node on a 64-bit machine. If you are running node on a 64-bit or 32-bit machine then the nodejs folder should be located in Program Files and Program Files (x86) respectively.