I'm using Amazon EC2 to host my Node.js server. I connect through ssh from my desktop, and once I run my server via ssh, I can turn my console off and everything will still work, obviously, since the process is running on my remote EC2 hosting server. But once I ssh again, I know the Node process is still running, but there seems to be no way to view the process logs, and this server is still in early beta versions that the console logs are important. Any help?
You could redirect stdout/stderr to a file, which would allow you to use ordinary tools like cat and tail to view the logs.
If you don't want to write the log output to file(s), you could start the process in screen or tmux or similar and attach to the session later from ssh.
Related
I have a Google VM, and i can start a web server. The command i issue is: python server.py.
My plan is to have the application running.
Since i will eventually close my pc (and thus the terminal), will the application continue running normally?
Or, do i have to start the server and then use disown, to make the app run in the background?
NOTE: If the second option is the case, does this mean that when i re-log in, and i want to shut down the server, the only way to do it is with pkill?
I'm newbie using GCP and his Compute Engine Service. I've deploy a Linux Ubuntu Image an it's running like a charm, but I have a issue running Node JS backend.
Let me explain it better:
I'm connecting using Web Browser SSH terminal or GCloud Shell ssh, and it way works running node app.js my backend starts working. But after a time, the sessions stop and my backend service stop working as well. At this time every time when I need to work have to re-activate the service each time.
How could I do for this service works in background and not depends that my ssh terminal are opened?
Thanks a lot in advance.
What actually happen is you are starting your nodejs application using an client which is parent process. So if after sometime the connection is lost of some xyz seconds the parent process dies killing your node application. Now what you can do is use screen. On ubuntu you would do something like this.
sudo apt-get install screen
after successful install run the screen command. Now you will be thrown a brand new terminal. Here you can run your nodejs code which will never die. Since screen runs your application in background. More information here
A good solution could be to use a startup script. To insert a startup script into your already created instance you need to go to this link [1]. When you have your startup script inserted in the metadata field you just need to restart your Instance and then should work perfectly without depending of the ssh session.
[1] https://cloud.google.com/compute/docs/startupscript#startupscriptrunninginstances
I've created this npm package, to make your node app run as a service on your linux machine. Please try it out.
It creates a systemctl service on your machine and runs it as a background service.
I'm developing on the same server where I host some webpages, in this case with Ajenti, nginx and node.js installed on a Ubuntu Server, and I noticed that when I crash the server in a test, I need to log in to ajenti or ssh and restart the webpages.
This made me wonder if nginx or Ubuntu can detect such a crash like a 502 Bad Gateway Error and if there is also a command or tool to restart the webpages?
With this I could probably script it all up and get the webpages restarted, automatically, every time I do something to crash the server.
One solution might be to use something like monit which can (among many other things) check for (and optionally restart) crashed processes.
I have deployed a Bitnami AMI of NodeJS on an AWS micro instance. After starting my node app, everything works fine.
After some time without any activity, the app which is attached to port :3000, seems to shut down. When this happens on refreshing the page my browser gives the message:
Network Error (tcp_error)
A communication error occurred: "Connection refused"
The Web Server may be down, too busy, or experiencing other problems preventing it from responding to requests. You may wish to try again at a later time.
The AWS console shows the instance is still running and the Bitnami build still responds with the standard message on port 80.
Forever (https://github.com/nodejitsu/forever) is also a useful tool for this kind of thing, and it gives you a little more control than nohup or screen.
As we discussed in comments, the problem was binding the node process to SSH session.
You can use nohup or screen to launch the node process in an instance not bound to session.
I suggest using screen because the function of returning to launched instance is essential for maintenance/updating.
Related: How to run process as background and never die
Related: Command-Line Interface tool to run node as a service
Besides configuring an EC2-instance you can also use the PaaS-solution of AWS, namely Elastic Beanstalk. They have also support for Node.js and it's super easy to deploy your apps using this service.
I absolutely 100% new to VPS and linux as of yesterday, and I'm running into an issue. Here's the process:
I SSH into my VPS box in OSX terminal. The VPS is running CentOS 6 for what it's worth.
I navigate to the correct folder and I run node app.js to launch my app in NodeJS/ExpressJS.
App launches and is readily accessible via the web at my VPS' ip address + the allocated port number.
If I put my laptop to sleep, the app crashes and is no longer accessible via web.
Again, being new to Linux I'm not sure how to solve this problem. It makes sense, as the terminal that was running/taking logs of the node app is no longer responding, but what I'd like is:
a) To be able to start up the app remotely then have it just...run...forever, until I manually stop it
b) To be able to SSH back into my server intermittently to check the logs, either via my mobile phone or my laptop.
Are either of these two things possible? Clearly my protocol of launching the app via terminal (as I'd normally do if running it locally) isn't the correct way to do it but I'm having trouble finding resources telling me what to do!
EDIT: I'm actually using Node Supervisor to run the app which helps keep it up and running when things crash, not sure if that affects the situation.
Most probably your app is printing to standard out (the console), and that stream is closed/broken, when you put your laptop to sleep.
There are at least two options:
Use screen: Just type screen before starting your app. Then start your app. Then Ctrl-A-D to detach from the screen. You can then safely log out from the VPS and put your laptop to sleep. To go back to the output of your app, log back in and type screen -r
Run the app in the background: node app.js &.