Why pm2 is fine, but pm2 logs is not? - node.js

I'm using pm2 to keep tracking of what I do on backend with NodeJS. Until yesterday it all worked perfectly fine, but today, even if pm2 server is working fine (i can start the project server and i can navigate), pm2 logs just stopped for no reasons.
Here you can see the version I'm using (i already updated PM2 both on project and local as i find in other answers).
I usually use the command
pm2 start process.json
pm2 restart 0 --watch
pm2 restart 0
And in other prompt instance, for the logs i use
pm2 logs
For some reason PM2 is just tailgating the last 15 lines but it doesn't work real time like it used to do
I didn't find this exact problem on other questions (only questions about pm2 not working at all, but not about pm2 working half way). Any suggestions?

Apparently the version of node and pm2 were the source of the problem. I used this command to run pm2 using the node version explicitly
pm2 start process.json --interpreter=/home/ken/.nvm/v10.15.1/bin/node
This way you force pm2 to use settings for the version of node you've installed in your machine. Now both server and logs works fine.

Related

Nodejs API doesn't work after reboot centos server

In my centos server, I have an API with node js and I started with pm2. pm2 status is online and It works correctly. but when server reboot, can't connect to the API although pm2 status is online.
I also try start node js like below
pm2 start index.js
pm2 startup
pm2 save
but It does not work until I restart pm2 ..
how can I fix it?
You have to do pm2 resurrect to start an application after "pm2 saving" it:
pm2 resurrect
Then put this command in a script file and configure it to run on server reboot. Read this Q and A for help. Also in this article there are some CentOS specific changes that need to be done.

PM2 to start multiple Node Applications with npm start on boot(using raspberry pi)

How can I run multiple nodejs applications using command npm start in different directories using pm2 on boot? Also how do i setup them to start again if any error occurs?
I figured out how to start npm start with pm2 using - "pm2 start npm -- start"
but I don't understand how to set up them to boot.
Based on my research "pm2 startup" gives the command to setup startup which I passed as it is in the terminal.
How do I set up the rest?
Thanks,
If you've already got the part where pm2 automatically starts when you reboot, that's good.
You then need to add each of your apps to pm2.
Go into each of your project directories and run
pm2 start your_file.js --name=my_app, where your_file.js is the file you would use to start with regular node. (ie: node server.js, or node index.js, etc.) and my_app is a friendly name that you will see with pm2 status and can use to apply future commands to.
This should start your app. If you run pm2 status it is hopefully in the "running" state.
To save it so that it automatically gets booted when you reboot or restart pm2 you need to run pm2 save whenever you change app configurations.
You can do this for as many apps as you need to start.

Getting error when trying to launch node.js app with PM2 Cluster

in an Ubuntu Server, I am unable to run the node.js app in cluster mode using PM2.
The command I use is :
PM2 start server.js --name Server -i max
When I list the PM2 processes, I can see the Server has Error status.
I have tried looking into the log file generated by PM2 but it's empty.
I am however able to run the same server.js without the cluster mode using :
PM2 start server.js --name Server
doing PM2 Kill and starting all the services again was the solution to above issue.
You could also have used pm2 restart Server to restart it
If you use pm2 kill you will just kill all processes, to clean up afterwards i would recommend to use pm2 flush so all logfiles will be reset
I have gone through this same kind of situations but in my case pm2 is showing error status cause of error in my code.
use the below command
pm2 logs
pm2 logs command helped me by showing some hints to check where exactly the error is occured.
if everything works fine then pm2 list will show you the status online.
you can check the ports running by pm2(not only pm2 but all the process) using below command
sudo netstat -tulpn

pm2 is not working in amazon ec2 with node application

I have node application hosted in amazon ec2.
I used nginx to point it in my domain.
It runs perfectly when i use npm start to run the application.
But when i use pm2, it doesnt work.
pm2 list command shows that the app is running.
But url doesn't work. Even when i again run npm start app gets started that clearly states that the port is free. So pm2 is not actually running anything on that port. But pm2 says app is online.
I was running the wrong file from pm2. As it was express project, so i had to run bin/www
So the following command solve the issue:
pm2 start bin/www
Answered it here as well:
https://github.com/Unitech/pm2/issues/3252
Thanks

Amazon EC2 NodeJS server stops itself after 2 days even after using sudo nohup

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.

Resources