I have a Python pyramid application that I am running using uwsgi like so:
sudo /finance/finance-env/bin/uwsgi --ini-paste-logged /finance/corefinance/production.ini
Once it's running and my window times out, I am unable to stop the server without rebooting the whole box. How do I stop the server?
You can kill uwsgi process using standard Linux commands:
killall uwsgi
or
# ps ax|grep uwsgi
12345
# kill -s QUIT 12345
The latter command allows you to do a graceful reload or immediately kill the whole stack depending on the signal you send.
The method you're using, however, is not normally used in production: normally you tell the OS to start your app on startup and to restart it if it crashes. Otherwise you're guaranteed a surprise one day at a least convenient time :) Uwsgi docs have examples of start scripts/jobs for Upstart/Systemd.
Also make sure you don't really run uwsgi as root - that sudo in the command makes me cringe, but I hope you have uid/gid options in your production.ini so Uwsgi changes the effective user on startup. Running a webserver as root is never a good idea.
If you add a --pidfile arg to the start command
sudo /finance/finance-env/bin/uwsgi --ini-paste-logged /finance/corefinance/production.ini --pidfile=/tmp/finance.pid
You can stop it with the following command
sudo /finance/finance-env/bin/uwsgi --stop /tmp/finance.pid
Also you can restart it with the following command
sudo /finance/finance-env/bin/uwsgi --reload /tmp/finance.pid
Related
In a server that I'm working on, There are many apache processes running in background. Is it safe to kill all the processes? If so, please guide me the steps involved in it. I have seen 12 httpd commands running as per result of top command, hope it helps in debugging the problem.
You can kill httpd process using this command
sudo kill `pgrep httpd`
Source: https://www.cyberciti.biz/faq/kill-process-in-linux-or-terminate-a-process-in-unix-or-linux-systems/
OR
Stop the Apache service with:
sudo systemctl stop httpd.service
Prevent Apache from loading when the system boots:
sudo systemctl disable httpd.service
Source: https://phoenixnap.com/kb/how-to-restart-apache-centos-linux
Start nodejs app on linux server with ssh(if i close the ssh connection,app stopped why?)
1-create nodejs app -its oke
2-run on linux server -its oke(i stop the apache server)
But if i close the ssh connection(with my windows pc),app stopped.How can i solve this problem?
The most correct thing to do is to write a service file for it so whatever init system you have (likely systemd) will keep it running and manage the start/stop/restart stuff for you.
Failing that (and I don't blame you...) you can run it within the screen utility. Launch it with screen -d -m /path/to/start/script and then you can come back later and reconnect to it with screen -r or screen -r <pid of the screen session>.
Note that launching it that way won't restart it, etc. To do that, you could do something like
#!/bin/sh
while true
do
sleep 3s
/path/to/start/script
done
And call that with the screen command.
Use the nohup command to start the application. Like:
nohup THE_COMMAND_YOU_DONT_WANT_TO_STOP_WHEN_YOU_LOGOUT &
With nodemon it might be helpful to put the command to start the server in a file called myserver.sh containing:
nodemon server.js
Make sure the file is executable:
chmod +x myserver.js
And then run
nohup myserver.sh &
When I run dsc cassandra on CoreOS(tarball) using telnet everything comes up fine. But when i close the telnet session, it kills the process. How do i keep the cassandra server running?
I tried sudo bin/cassandra and sudo bin/cassandra -f
both didnt help.
I have no issues in other OS.
Option Description
-f Start the cassandra process in foreground. The default is to start as background process.
-h Help.
-p filename Log the process ID in the named file. Useful for stopping Cassandra by killing its PID.
-v Print the version and exit.
When you are starting cassandra using -f it runs in foreground, hence it will stop as soon as terminal is closed. Same is true for background process.
This will happen with any application you run in telnet session.
You can try
sudo service cassandra start OR nohup bin/cassandra this will keep your application running even when terminal is closed
You need to run Cassandra as a systemd service, as described here: https://coreos.com/os/docs/latest/getting-started-with-systemd.html
Running in the foreground with cassandra -f as your ExecStart= command will allow systemd to manage the state of the process (ideally inside a container).
While this is a bit different than what you're used to, it will lead to an overall more stable mechanism since you'll be using an init system that understands dependency chains, restart and reboot behavior, logging, etc.
Run the process in a screen or tmux session. Detaching from the screen session should allow the process to keep running.
I have recently completed the Wiki web development tutorial (http://golang.org/doc/articles/wiki/). I had tons of fun and I would like to experiment more with the net/http package.
However, I noticed that when I run the wiki from a console, the wiki takes over the console. If I close the console terminal or stop the process with CTRL+Z then the server stops.
How can I get the server to run in the background? I think the term for that is running in a daemon.
I'm running this on Ubuntu 12.04. Thanks for any help.
Simple / Usable things first
If you want a start script without much effort (i.e. dealing with the process, just having it managed by the system), you could create a systemd service. See Greg's answer for a detailled description on how to do that.
Afterwards you can start the service with
systemctl start myserver
Previously I would have recommended trying xinetd or something similar for finer granuarlity regarding resource and permission management but systemd already covers that.
Using the shell
You could start your process like this:
nohup ./myexecutable &
The & tells the shell to start the command in the background, keeping it in the job list.
On some shells, the job is killed if the parent shell exits using the HANGUP signal.
To prevent this, you can launch your command using the nohup command, which discards the HANGUP signal.
However, this does not work, if the called process reconnects the HANGUP signal.
To be really sure, you need to remove the process from the shell's joblist.
For two well known shells this can be achieved as follows:
bash:
./myexecutable &
disown <pid>
zsh:
./myexecutable &!
Killing your background job
Normally, the shell prints the PID of the process, which then can be killed using the kill command, to stop the server. If your shell does not print the PID, you can get it using
echo $!
directly after execution. This prints the PID of the forked process.
You could use Supervisord to manage your process.
Ubuntu? Use upstart.
Create a file in /etc/init for your job, named your-service-name.conf
start on net-device-up
exec /path/to/file --option
You can use start your-service-name, as well as: stop, restart, status
This will configure your service using systemd, not a comprehensive tutorial but rather a quick jump-start of how this can be set up.
Content of your app.service file
[Unit]
Description=deploy-webhook service
After=network.target
[Service]
ExecStart=/usr/bin/go webhook.go
WorkingDirectory=/etc/deploy-webhook
User=app-svc
Group=app-svc
Restart=always
RestartSec=10
KillSignal=SIGINT
SyslogIdentifier=deploy-webhook-service
PrivateTmp=true
Environment=APP_PARAM_1=ParamA
Environment=APP_PARAM_2=ParamB
[Install]
WantedBy=multi-user.target
Starting the Service
sudo systemctl start deploy-webhook.service
Service Status
sudo systemctl status deploy-webhook.service
Logs
journalctl -u deploy-webhook -e
After you press ctrl+z (putting the current task to sleep) you can run the command bg in the terminal (stands for background) to let the latest task continue running in the background.
When you need to, run fg to get back to the task.
To get the same result, you can add to your command & at the end to start it in the background.
To add to Greg's answer:
To run the Go App as a service you need to create a new service unit file.
However, the App needs to know where Go is installed. The easiest way to lookup that location is by running this command:
which go
which gives you an output like this:
/usr/local/go/bin/go
With this piece of information, you can create the systemd service file. Create a file named providus-app.service in the /etc/systemd/system/ using the command below:
sudo touch /etc/systemd/system/providus-app.service
Next open the newly created file:
sudo nano /etc/systemd/system/providus-app.service
Paste the following configuration into your service file:
[Unit]
Description=Providus App Service
After=network.target
[Service]
Type=forking
User=deploy
Group=deploy
ExecStart=/usr/local/go/bin/go run main.go
WorkingDirectory=/home/deploy/providus-app
Restart=always
RestartSec=10
KillSignal=SIGINT
SyslogIdentifier=providus-app-service
PrivateTmp=true
[Install]
WantedBy=multi-user.target
When you are finished, save and close the file.
Next, reload the systemd daemon so that it knows about our service file:
sudo systemctl daemon-reload
Start the Providus App service by typing:
sudo systemctl restart providus-app
Double-check that it started without errors by typing:
sudo systemctl status providus-app
And then enable the Providus App service file so that Providus App automatically starts at boot, that is, it can start on its own whenever the server restarts:
sudo systemctl enable providus-app
This creates a multi-user.target symlink in /etc/systemd/system/multi-user.target.wants/providus-app.service for the /etc/systemd/system/providus-app.service file that you created.
To check logs:
sudo journalctl -u providus-app
I connect to my remote server via ssh. Then I start my node.js app with Forever. Everything works fine until I close my console window. How to run node.js app FOREVER on my remote server even when I close my connection via ssh? I just want to start an app and shut down my copmputer. My app should be working in the background on my remote server.
You may also want to consider using the upstart utility. It will allow you to start, stop and restart you node application like a service. Upstart can configured to automatically restart your application if it crashes.
Install upstart:
sudo apt-get install upstart
Create a simple script for your application that will look something like:
#!upstart
description "my app"
start on started mountall
stop on shutdown
# Automatically Respawn:
respawn
respawn limit 99 5
env NODE_ENV=production
exec node /somepath/myapp/app.js >> /var/log/myapp.log 2>&1
Then copy the script file (myapp.conf) to /etc/init and make sure its marked as executable. Your application can then be managed using the following commands:
sudo start myapp
sudo stop myapp
sudo restart myapp
Two answers: One for Windows, one for *nix:
On Windows, you can use the start command to start the process disconnected from your instance of cmd.exe:
start node example.js
On *nix, there are two aspects of this: Disconnecting the process from the console, and making sure it doesn't receive the HUP signal ("hang up"), which most processes (including Node) will respond to by terminating. The former is possibly optional, but the latter is necessary.
Starting disconnected from the console is easy: Usually, you just put an ampersand (&) at the end of the command line:
# Keep reading, don't just grab this and use it
node example.js &
But the above doesn't protect the process from HUP signals. The program may or may not receive HUP when you close the shell (console), depending on a shell option called huponexit. If huponexit is true, the process will receive HUP when the shell exits and will presumably terminate.
huponexit defaults to false on the various Linux variants I've used, and in fact I happily used the above for years until coderjoe and others helped me understand (in a very long comment stream under the answer that may have since been deleted) that I was relying on huponexit being false.
To avoid the possibility that huponexit might be true in your environment, explicitly use nohup. nohup runs the process immune from HUP signals. You use it like this:
nohup node example.js > /dev/null &
or
nohup node example.js > your-desired-filename-or-stream-here &
The redirection is important; if you don't do it, you'll end up with a nohup.out file containing the output from stdout and stderr. (By default, nohup redirects stderr to stdout, and if stdout is outputting to a terminal, it redirects that to nohup.out. nohup also redirects stdin if it's receiving from a terminal, so we don't have to do that. See man nohup or info coreutils 'nohup invocation' for details.)
In general for these things, you want to use a process monitor so that if the process crashes for some reason, the monitor restarts it, but the above does work for simple cases.
I would definitely recommend pm2
npm install -g pm2
To start server: pm2 start [yourServerFile.js]
To stop server: pm2 stop [yourServerFile.js]
Close client and server will run forever....will also restart if app crashes.
Ive been running a node server on Ubuntu for months with zero issues
Always, simple is the best, no need upstart, no need forever, just nohup:
nohup node file.js &
Believe me, I'm running so that for my case!
You could install forever using npm like this:
sudo npm install -g forever
Or as a service:
forever start server.js
Or stop service
forever stop server.js
To list all running processes:
forever list
node expamle.js & for example
In Linux, SSH into your remote server and run
screen
to launch into a new screen.
Finally, type ctrlad to detach the screen session without killing the process.
More info here.
I had similar issue and I think using forever will help to handle crashed and restarts
You can install forever globally:
sudo nom install -g forever
And run this command:
nohup forever server.js &
This should handle all the trouble of closing the terminal, closing ssh session, node crashes and restarts.
If you're running node.js in a production environment, you should consider using PM2, forever.js, or Nodemon.
There is no shortage of articles online comparing the different packages.
This is only a partial answer for Windows. I’ve created a single line Visual Basic Script called app.vbs that will start your node application within a hidden window:
CreateObject("Wscript.Shell").Run "node app.js", 0
To execute it automatically at startup, open the %AppData%\Microsoft\Windows\Start Menu\Programs\Startup\ directory and add a shortcut to the app.vbs file.
More info at: https://keestalkstech.com/2016/07/start-nodejs-app-windowless-windows/
Wow, I just found a very simple solution:
First, start your process (node app)
forever dist/index.js
run: ^Z cmd + z.
Then: bg. Yeah.. bg (background).
And pum.. you are out.
Finish with exitif you are with sshor just close the terminal.
my start.sh file:
#/bin/bash
nohup forever -c php artisan your:command >>storage/logs/yourcommand.log 2>&1 &
There is one important thing only. FIRST COMMAND MUST BE "nohup", second command must be "forever" and "-c" parameter is forever's param, "2>&1 &" area is for "nohup". After running this line then you can logout from your terminal, relogin and run "forever restartall" voilaa... You can restart and you can be sure that if script halts then forever will restart it.
I <3 forever