system cron not running intended process scheduled for execution - linux

I have node server that I want to restart whenever it stopped. For this case I setup system cron on ubuntu server to execute a simple bash script that will track node server every minute and log the server status. Now this cron trigger this bash script and logs relevant status every minute but node server doesn't execute(Using simple linux command I can check if node server running or not). When manually running that bash script node server starts but something happening when cron executes that script. I am trying to fix this meanwhile any help will be appreciated.
Thanks

instead of doing this with cron i think you have to use spervisor in order to keep the process running check this supervisor website

Related

Running a node script 'forever' in heroku (or aws) with no front end?

I have a requirement of running a node script (not app or dapp), which has no front -end files (html, css). This script will send transactions (call smart contract function) in regular intervals. the only constraint is that this script needs to run perpetually (forever) without stopping, unless a specific command is given by admin. Please do suggest how we could achieve this? Thanks.
PS: in case you have a better platform suggestion other than heroku, those are welcome as well with details. Tx.
Unix cron works fine for this kind of things. Just add a cron in your crontab with command :
crontab -e
Then just set your pattern and add a line with your command to launch, for example this will run each day at 3.00 AM:
0 3 * * * /root/backup.sh
Then don't forget to reload your cron process:
sudo service cron restart
Define your pattern here : https://crontab.guru/
You can have a look at kue.
The good thing about kue is, that it gives you a UI where an admin can view the running, failed, jobs etc. Also, you can configure it to stop a job programmatically.

Run a command every 5 minutes and stop it at the end of that time

I have to run NodeJS application which has to run uninterruptedly, but I need to stop it and restart it every 10 minutes.
I'm Working on a dedicated Ubuntu 18.04 machine.
I have read something about cron but I don't know well how it works. Does it stop the command that was run with it?
You can use forever to run the application, and set up a cron job to restart it in forever every five minutes. As a bonus, forever will also restart it for you if it fails in between cron job executions.
In my knowledge, the cron doesn't stop the command that had run before, but you could add the logic to do that check in your application.
Here you can find an article that shows some solutions to prevent duplicate cron job executions.

Trying to write a shell script to monitor when a service stops in linux, and to automate the restart of this service

So I am relatively new to Centos, version 6.2. I have a service that needs to be mnonitored as a cron job, and if it stops needs to be restarted. I have a few ideas on how to monitor it, but when it comes to getting it restarted thats when I get stuck. I also know the PiD of the service I want to monitor.
You can use supervise for this: http://cr.yp.to/daemontools/supervise.html
Put it in your crontab to launch on system start:
#reboot supervise foo

DigitalOcean stop Node.js server running with nohup

I am running a Node.js server on a DigitalOcean droplet (with Ubuntu). I have worked out how to make it run when I'm not connected to it via Putty. However, just one issue: how do I stop it now?
I can see that control+C works when in the session, but what if I exit the session and come back? How will I stop the server then?
Also, will running it multiple times run multiple servers at once?
Thanks!
You really should be using a tool like supervisord (http://supervisord.org/) for your long-running processes.
But if you want to stop an already running process that you started with nohup then look up the process ID first (with ps aux and look/grep for your process) and then run kill <<pid>>.

Reload node server on command

Is there a way to trigger the node server to reload on a command
Something like;
if(checkFirstInCmd("RESTART",cmd){
RESTART.NODE.SERVER
}
There is no built-in way to restart a node server. For example: if a node server crashes it will stop the node process.
One solution that came to my mind was something like a shell script that you could spawn with a child process. The script could kill your server and maybe wait some seconds till it's killed and than restart it again.

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