I found that one of the problems in cloud computing and remote HPC is the disconnection of the signal. Most of the processes on cloud and HPC are heavily worked and take a long analysis time. If the connection on your local computer is poor, the screen is lost, which means what you run on the remote computer stops. To solve this issue, I have tried many ways, such as using snap or running a Docker container in the background. However, the most convenient way is using the command screen.
First, you need to install screen on your remote computer (either cloud computing or remote HPC). Now the screen can work properly just by calling the screen command. However, I want it to be easier to work with. Tommy suggested using the screen command and .screenrc file in his video. I followed his suggestion by doing the steps below.
First, install screen if it is available on your system. For HPC, if you can’t run the command below, it means that you are not an admin. The installation requires the system administrator (root).
sudo apt install screen
.screenrc file at $HOME Then, go to your home directory and create a .screenrc file using nano.
# Go to home directory
cd ~
# Create a `.screenrc` file using nano
nano .screenrc
Put the script below to the .screenrc file.
# Script for `.screenrc` file on home directory
startup_message off
vbell off
autodetach on
shell -$SHELL
bind c screen 1
bind ^c screen 1
bind 0 select 10
screen 1
term xterm-256color
hardstatus alwayslastline
# Very nice tabbed colored hardstatus line
hardstatus string '%{= kG}[ %{G}%H | %{R}%l %{g}][%= %{= kw}%?%-Lw%?%{r}(%{W}%n*%f%t%?(%u)%?%{r})%{w}%?%+Lw%?%?%= %{g}][%{B} %d/%m %{W}%c %{g}]'
# change command character from ctrl-a to ctrl-b (emacs users may want this)
#escape ^Bb
# Hide hardstatus: ctrl-a f
bind f eval "hardstatus ignore"
# Show hardstatus: ctrl-a F
bind F eval "hardstatus alwayslastline"
You can use the ls and cat commands to check it, then re-run the screen command again.
# To list all objects including hided object.
ls -al
# To obserse the `.screenrc` file
cat .screenrc
screen commandTo start using screen, we run this command.
screen
This is the terminal after adding the .screenrc file and ran the screen command.
\
Here is the useful commands for using screen.
# list all screen
screen -ls
# resume the screen section
screen -r # if you have only one screen
screen -r <screen no> # if you have more than one screen, you will need to define which one you want to open
After you open the screen as shown in the picture, these are the useful commands that I often use.
Ctrl+a c : Create a new window (with shell).
Ctrl+a 0 : Switch to window 0 (by number).
Ctrl+a X : Close the current region.
Ctrl+a d : Detach the screen section.
Ctrl+a k : Kill the screen section. \
Please note that after the computer is shut down, all screens will be terminated. If you are running something on the screen, such as Dockerized R Studio, don’t forget to close it properly. Otherwise, it might affect your files.