How to continuously run a Python script on an EC2 server?

Question

I've setup an Amazon EC2 server. I have a Python script that is supposed to download large amounts of data from the web onto the server. I can run the script from the terminal through ssh, however very often I loose the ssh connection. When I loose the connection, the script stops.

Is there a method where I tell the script to run from terminal and when I disconnect, the script is still running on the server?

Answer 1

You have a few options.

• You can add your script to cron to be run regularly.
• You can run your script manually, and detach+background it using nohup.
• You can run a tool such as GNU Screen, and detach your terminal and log out, only to continue where you left off later. I use this a lot.
  • For example:
    1. Log in to your machine, run: screen.
    2. Start your script and either just close your terminal or properly detach your session with: Ctrl+A, D, D.
    3. Disconnect from your terminal.
    4. Reconnect at some later time, and run screen -rD. You should see your stuff just as you left it.
• You can also add your script to /etc/rc.d/ to be invoked on book and always be running.