I'm building an E-commerce site, where there's an Authentication system.
I noticed that if the client login with a wrong user or password, the backend/server that works with nodemon will crach and hang in there crashed till i restart manually nodemon. This is example output error of the nodemon crash:
[nodemon] app crashed - waiting for file changes before starting...
node:internal/errors:464
ErrorCaptureStackTrace(err);
^
Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent
to the client
Ofcourse, when server crashes, client can no more access or do login again till server restarts.
After some googling, i found this question and this repository that fix my problem but particulary and not as expected precisely, i dont want nodemon to restart forever on any error that occure ofcourse, but only with specifics errors that i set them -like Authentication errors as i mentionned above-.
So, my idea/question is: is there anyway to get nodemon restarts by itself in some cases of failures or errors (NOT ALL)?
Seems like you a referring to a production situation, and nodemon is a development node server, which is not intended for use in production, as the intro states:
nodemon is a tool that helps develop Node.js based applications by
automatically restarting the node application when file changes in the
directory are detected.
You should use node.js in production, instead of nodemon.
For managing your node server in production, you could use a process manager like PM2..
That said, an authentication server that crashes every time a user uses a wrong password seams very ineffective in handling a common use case. So I would advise to start with fixing the root cause, which is the buggy server, and then for recovery from incidental crashes use something like PM2.
PS:
The error you are getting looks like an express error you get when you send a response (in this case an error response) without exiting the function e.g. by using return. Because you are not returning, another res.send is called, which causes the 'ERR_HTTP_HEADERS_SENT' error. See this answer.
This is really bad since it can send your program into a loop of restarting, but if you really want it, replace app.js with your file's name and try this:
nodemon -x 'node app.js || copy /b app.js +,,'
Linux version:
nodemon -x 'node app.js || touch app.js'
Next time try a little googleing before you ask since it is most likely faster.
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 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
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) -
Open command prompt and type %appdata% press enter
Navigate to %appdata% > npm folder
Open or Edit ng.cmd in your favorite editor
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" %*
)
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:
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.
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).
Remove all logging/tracking tools like APM , Kafka , UTM tracking, Prerender (SEO) etc middlewares or turn off.
Now code level debugging: In your main server file , remove unwanted console.log which is just printing a message.
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.
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"
Unix (Mac OS)
Open a terminal and open our .zshrc file using nano like so (this will create one, if one doesn't exist):
nano ~/.zshrc
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).
Save and exit nano by pressing: ctrl + x, then y to agree and finally enter to save the changes.
Close and reopen the terminal to make sure our changes have been recognised.
We can print out the contents of our .zshrc file to see if our changes were saved like so: cat ~/.zshrc.
Linux (Ubuntu)
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
Use the option --optimize-for-size. It's going to focus on using less ram.
I had this error on AWS Elastic Beanstalk, upgrading instance type from t3.micro (Free tier) to t3.small fixed the error
In my case, I upgraded node.js version to latest (version 12.8.0) and it worked like a charm.
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.
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
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.
I had the same issue in a windows machine and I noticed that for some reason it didn't work in git bash, but it was working in power shell
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!
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.
None of all these every single answers worked for me (I didn't try to update npm tho).
Here's what worked: My program was using two arrays. One that was parsed on JSON, the other that was generated from datas on the first one. Just before the second loop, I just had to set my first JSON parsed array back to [].
That way a loooooot of memory is freed, allowing the program to continue execution without failing memory allocation at some point.
Cheers !
You can fix a "heap out of memory" error in Node.js by below approaches.
Increase the amount of memory allocated to the Node.js process by using the --max-old-space-size flag when starting the application. For example, you can increase the limit to 4GB by running node --max-old-space-size=4096 index.js.
Use a memory leak detection tool, such as the Node.js heap dump module, to identify and fix memory leaks in your application. You can also use the node inspector and use chrome://inspect to check memory usage.
Optimize your code to reduce the amount of memory needed. This might involve reducing the size of data structures, reusing objects instead of creating new ones, or using more efficient algorithms.
Use a garbage collector (GC) algorithm to manage memory automatically. Node.js uses the V8 engine's garbage collector by default, but you can also use other GC algorithms such as the Garbage Collection in Node.js
Use a containerization technology like Docker which limits the amount of memory available to the container.
Use a process manager like pm2 which allows to automatically restart the node application if it goes out of memory.
I have completed todo app by learning from this video:
Super MEAN Stack Tutorial: Angular, Node/Express, Webpack, MongoDB, SASS, Babel/ES6, Bootstrap
In that video at time 19:18 at this url it is taught that I should use the below two commands in seperate git-bash instances if I want to run it in windows using npm run dev:
node server
webpack-dev-server --progress --colors
But in Linux (or any other OS than windows) you can use this script:
"Scripts": {
"start": "NODE_PATH=$NODE_PATH:./src node server",
"dev": "npm start & webpack-dev-server --progress --colors"
}
So, Is there any way I can do the same in windows?
Also, In that tutorial I can see that port no. 3000 is assigned to node server, but due to using dev dependencies he runs the localhost:8080 in browser. You can see that here. After the tutorial finishes, I followed along and created that app. Now I would like to deploy it. So, I would first like to learn to run test my site in non-dev dependencies mode. i.e. when I type localhost:3000 in browser, my app should run successfully. So, can anybody explain the steps for that?
Update:
I am a newbie in node.js. I watched many videos on node and tried to learn something from that. In all the videos I see that I run node server on port no. 3000 and then I type localhost:3000 in my browser. Now lastly I watched video about mean stack in which he uses webpack. Now, I am confused. I think there are two servers running. first server is webpack's server and second server is node's server. Upto today I typed localhost:3000 in my browser because I mentioned that port 3000 will be used by node in my code. But now in the video he is running localhost:8080 in browser. It means webpack's server is used. Then what happened to node server. Why can't I just run localhost:3000? Also in the video it is explained that webpack is a dev dependency. So, I think after the app is completed and ready to be deployed, my project can be run on the node server (by making some changes to the code, I am not sure). Let's take an example. Now I don't want to deploy the app to a real server. I want the same app to run on my friend's pc. He is not a developer. So, he should not depend on webpack as webpack is a dev dependency. So, he should be able to run the app on node server instead of webpack's server. So, he should type localhost:3000 instead of localhost:8080. That's what I don't understand.
Let's break this down:
If you've defined this script:
"Scripts": {
"start": "NODE_PATH=$NODE_PATH:./src node server",
"dev": "npm start & webpack-dev-server --progress --colors"
}
... then this npm command: npm run dev
... actually invokes these two actions:
a) npm start & # Runs NPM in the background
b) webpack-dev-server --progress --colors # Concurrently runs webpack in the foreground
You can accomplish the same thing in many ways using Windows, starting with a simple .bat file like this:
EXAMPLE: RunDev.bat:
start npm start
webpack-dev-server --progress --colors
=======================================================================
STRONG SUGGESTION:
Please forget about watching videos for a few moments. Try a couple of "hello world" tutorials. More importantly, play with the actual code. Try changing things in the code, and see what happens.
Forget about webpack, at least for the moment.
Think of npm as a "build tool"; not as a way to run your application. At least for a moment.
Focus on "node". Write a "node application".
Part of your "node application" will require "ExpressJS" and "Jade" (now renamed "pug" - I'm still using "Jade"). Use npm to get your ExpressJS and Jade dependencies, but stay focussed on Node.
SUGGESTED TUTORIAL:
A Simple Website in Node.js, Ben Gourley
Be sure to:
a. Download the code
b. Work through the tutorial, using the downloaded code
Please post back (a new post) with any specific questions you might have as you work through the tutorial.