I have a small node.js (v13.5.0) server running under PM2 (v4.4.0) on a RHEL 7.6 box. As a part of it's function it writes a small CSV file to the disc for every incoming request. This app is writing these files with the perms (rw-r-----).
The user I am having PM2 executing my process as has umask set to 0022. I have confirmed this is effective as it works in other cases.
So the main problem is that I cannot get my pm2+node combo to use the umask to write files with the right permissions.
Any suggestions where i am going wrong?
Thanks in advance,
So using ps fu -u $USER i figured out that PM2 daemon process had been running since i first started it (started column) - which was way before I made the umask change. As a result it was running with an outdated environment.
I restarted it using pm2 kill && pm2 start && pm2 ping which should return a pong. Subsequent tests proved that this had fixed the issue.
Related
I'm using the Mediatek 7688 board running OpenWRT linux to create an IoT device. I have written the app in NodeJS and want it to be executed anytime the board boots up.
I have tried the solution given [here] (How to auto start an application in openwrt?) while this works but the board seems to be unable to complete the boot process (the NodeJS app doesn't exit). I have also tried the pm2 npm module but am running into issues with diskspace during installation.
Is there a way to reduce the "installed" size of the pm2 module? Or maybe a way to fire up the NodeJS scripts upon startup without using the module.
Thanks in advance!
So I was only using the pm2 module to ensure that:
The program started at bootup
The program was restarted in case it crashed
To accomplish the first part and since my program was a node.js program, I made it into an executable file by adding #!/bin/sh env node as the first line in the file. Must ensure that the line ends in a LF line ending and not CRLF as in case of windows systems. Once done, I granted execute permission to the .js file by calling chmod a+x myfile.js.
I then created an init script in the /etc/init.d folder and enabled that script - as explained here
Now to ensure that the process restarted automatically in case it ever crashed, I a "cron script", like so and saved it a restart.sh in the root folder:
#bin/sh
if pgrep -f myfile.js > dev/null
then
#process is already running - do nothing
else
/etc/init.d/myprocess start
fi
And finally setup a crontab -e with * * * * * ~/restart.sh so that the restart.sh gets executed every minute to ensure that the process is running.
I have my app running on http://talkwithstranger.com/ and I have deployed it on AWS EC2. I use this command
sudo nohup node index.js &
To continue running my Node JS server even if I close my terminal and exit my SSH.
However, after 2 days everytime I wake up and I find out that the node server itself stops automatically. I checked the running processes by using
ps -ef
and my node script is not there.
Google Chrome say site DNS not found, because NodeJS Express is not running of course to serve my html file, but why it stops itself?
What is causing this unexpected shutdown of my server after every 2 days? I have to manually run nohup again to run it again.
Does nohup has a time to expire or something ?
You should run node.js using a service / process manager. You can use something basic such as forever or supervisord but I would actually advise you to take a look at PM2.
It can do a lot of things - one of them being that it manages your process, makes sure it keeps running, restarts it when it fails, manages the logs, etc. You can also have it autostart when you restart the server.
It becomes really powerful in combination with https://pm2.io, because this enables you to monitor your server's metrics such as CPU and memory remotely and see whether exceptions happened, and much more (such as even remotely updating the software by pulling from git). However, they no longer offer a free plan unfortunately - their plans now start at $79/month, which is a pity. But don't worry, the PM2 application itself is still free and open source, only the monitoring costs money.
Basic usage of PM2:
npm install -g pm2
...to install PM2.
pm2 start my_script.js
Starts a script and lets it run in background.
pm2 status
Shows the status of any running scripts.
pm2 restart all
Restarts all running scripts.
pm2 kill
Stops all scripts and completely shuts down the PM2 daemon.
pm2 monit
Monitors CPU/RAM usage and shows it.
pm2 logs
Shows the last 20 output and error log lines and starts streaming live logs to the console. The logs are stored in the folder ~/.pm2/logs.
Using PM2, your script will not stop - at most, it will restart. And if it does you will be able to more easily understand why because you can easily access logs and watch what happenes with memory usage, etc.
Extra tips:
To avoid filling up the harddisk with logfiles, I recommend installing the module pm2-logrotate:
pm2 install pm2-logrotate
To automatically launch PM2 with the same script on startup when the server starts, you can first save the current configuration:
pm2 save
...and then use the following command to install a startup script - follow the instructions displayed, which will be different based on the exact OS you are using:
pm2 startup
To use PM2 in a more advanced way with multiple processes, custom environment variables, etc., take a look at ecosystem files.
You can try forever.Install using the following command.
npm install -g forever
Then just start forever:
forever start index.js
Another better option for production use is pm2.You can install pm2 with below command
npm install -g pm2
# or
yarn global add pm2
start server
pm2 start index.js
The best thing is you can achieve load balancing with pm2(utilize all available CPU)
pm2 start index.js -i max
For more info, you can visit pm2 documentation page.
I am running a forever process for Node.js server but after one day the server stops the process.My server is running on Ubuntu platform. I have done the following process:
First I installed npm install forever and ran the command forever start server.js. I need the server to run for all the time but after one day I am seeing the server stops working.
Please help me to resolve this issue.
I would like to suggest that you try PM2 instead. Here's the short tutorial I wrote about it: http://www.nikola-breznjak.com/blog/nodejs/using-pm2-to-run-your-node-js-apps-like-a-pro/.
edit:
As per StackOverflow's policy I'm including the content from the post here also:
Running your Node.js application by hand is, well, not the way we roll. Imagine restarting the app every time something happens, or god forbid application crashes in the middle of the night and you find about it only in the morning – ah the horror. PM2 solves this by:
allowing you to keep applications alive forever
reloading applications without downtime
facilitating common system admin tasks
To install PM2, run the following command:
sudo npm install pm2 -g
To start your process with PM2, run the following command (once in the root of your application):
pm2 start server.js
As you can see from the output shown on the image below, PM2 automatically assigns an App name (based on the filename, without the .js extension) and a PM2 id. PM2 also maintains other information, such as the PID of the process, its current status, and memory usage.
As I mentioned before, the application running under PM2 will be restarted automatically if the application crashes or is killed, but an additional step needs to be taken to get the application to launch on system startup (boot or reboot). The command to do that is the following:
pm2 startup ubuntu
The output of this command will instruct you to execute an additional command which will enable the actual startup on boot or reboot. In my case the note for the additional command was:
sudo env PATH=$PATH:/usr/local/bin pm2 startup ubuntu -u nikola
As you can tell by my question, I'm new to this...
I built my first website, I set up my first Node.js server to serve it and then pushed everything live on EC2.
I tested everything on my EC2 IP address and everything seems to be working.
Now up until now, I've been testing my app locally so it makes sense that whenever I closed the terminal, app.js would stop running so nothing would be served on localhost.
Now that my server is on EC2, the same thing happens ("obviously" one could say..) whenever I close my terminal.
So my question is how do I keep my Node.js server running on EC2 for like... forever..so that my site stays live.. forever :)
I read something about a node module called "forever" but I'm wondering (being new and all..) why isn't this "forever" functionality a default setting of the Node.js-EC2 system ?
I mean, correct me if I'm wrong, but isn't the whole point of setting up a web server and pushing it live to have it stay live forever? Isn't that what servers are supposed to do anyway (infinitely listening for requests) ? And if that's the case why do we need extra modules/settings to achieve that ?
Thanks for your help.. As you can tell I'm not only looking for a solution but an explanation as well because I got really confused.. :-)
EDIT (a few details you might need) - After installing my app on EC2 these are the steps that I follow on the terminal (The app is running on Amazon Linux by the way) :
I type ssh -i xxxxxxxxxxx.pem ec2-user#ec2-xx-xx-xx-x.eu-west-1.compute.amazonaws.com on the
terminal
After logging onto the Amazon machine I then go to the relevant folder and execute node app.js
There are 3 folders in the machine : node, node_modules and *name of my app*
app.js resides in *name of my app*
After that, the site goes live on my EC2 IP
Once I close the terminal, everything is switched off
Before you invoke Node.js, run the command:
screen
This will create a persistent environment which will allow your process to keep running after you disconnect.
When you reconnect, you can use this command to reconnect to that environment:
screen -r
Here's a random link to learn more about screen:
http://www.rackaid.com/blog/linux-screen-tutorial-and-how-to/
However, this won't help you if your EC2 instance restarts. There are many different ways to do that. Adding your startup command to /etc/rc.local is one way. Here's a link to an Amazon guide which includes adding something to /etc/rc.local.
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/building-shared-amis.html
I worked with the valid answer for a while but some times the screen just end with no reason also screen has no balance loader and others features that in a production enviroment you should care , Currently I use a npm component to do this job.
https://www.npmjs.com/package/pm2
This is so easy to use.
$ npm install pm2 -g
then just start your app with pm2 like this
$ pm2 start app.js
In the above link you can find diferents tasks to perform if you need.
Hope this help the newbies like me.
There's a better way. Use forever.js.
See it here: https://github.com/foreverjs/forever
This is a nice tutorial for how to use chkconfig with forever on CENTOS.
http://aronduby.com/starting-node-forever-scripts-at-boot-w-centos/
Or use tmux
Just Enter a tmux screen run node server
Ctrl+b Hit D and you're done.
I am very late to join the thread and seems its basic problem with every newbie. Follow the below to setup properly your first server.
follow the step on the ec2 instance(before doing this make sure you have a start script for pm2 in your package.json file):
npm install pm2 -g
pm2 startup systemd
See the output and at the last line it must be like..
You have to run this command as root. Execute the following command:
sudo env PATH=$PATH:/usr/bin /usr/lib/node_modules/pm2/bin/pm2 startup
systemd -u sammy --hp /home/sammy
Take the last line command and run again with root privilege.
(before running the next command, Provide a new start script for pm2 in your package.json file e.g: "pm2-start": "pm2 start ./bin/www")
npm run pm2-start
for more info follow the link.
https://www.digitalocean.com/community/tutorials/how-to-set-up-a-node-js-application-for-production-on-ubuntu-16-04
If you are using a Ubuntu EC2, better to use the following we have been using this for the past 6 years and have had no issues with this.
sudo npm i -g forever
Now start your main, example
forever start index.js
forever start src/server.js
To stop the server use the following command
forever stop index.js
To list multiple servers running forever
forever listall
We are finishing development of a project, the client is already using it but occasionally some errors occur - crashing the server.
I know I could register a service as 'upstart' script on linux, in order to have my node service restart when it crashes.
But our server is running other stuff, so we can't restart it.
Well, actually, while writing, I realize I have two questions then:
Will 'upstart' work without having to reboot? Something is just whispering yes to me :)
If not, what other option would I have to 'respawn' my node server when it crashes?
Yes, upstart will restart your process without a reboot.
Also, you should look into forever.
PM2 is a Production process manager for Node.js app.
If your focus for automatic restart is an always running application, I suggest to use a process manager. Process manager, in general, handles the node process(es if cluster enabled), and is responsible for the process/es execution. PM leans on the operative system: your node app and the OS are not so strinctly chained because the pm is in the middle.Final trick: put the process manager on upstart. Here is a complete performance improvement path to follow.
Using a shared server and not having root privileges, I can't download or install any of the previously mentioned libraries. What I am able to do is use a simple infinite bash loop to solve my issue. First, I created the file ./startup.sh in the base directory ($ vim startup.sh):
#!/bin/bash
while:
do
node ./dist/sophisticatedPrimate/server/main.js
done
Then I run it with:
$ bash startup.sh
and it works fine. There is a downside to this, which is that is doesn't have a graceful way to end the loop (at least not once I exit the server). What I ended up doing is simply finding the process with:
$ ps aux | grep startup.sh
Then killing it with
$ kill <process id>
example
$ kill 555555