Questions[multiple-instances](ubuntu)

Previously, my dock icons showed several little red dots on their left side whenever I opened several instances of an application. I liked this feature because I could immediately tell that I had several instances, for example browser windows, running.

Now, I have only a red dash underneath the icon which tells me that one or maybe several instances are open. Is there anyway to get the 'little red dots' feature back?

I already applied

gsettings set org.gnome.shell.extensions.dash-to-dock click-action 'previews'

That's a nice feature but I am still missing the little red dots.

I am using GNOME 3.28.2 on Ubuntu 18.04.4 LTS.

I am struggling with organizing my workspaces. I have one workspace per Project I am working on. Some applications I can fix to a single workspace, since they are only needed for a single project. Others (like Firefox) I need on all workspaces. Now, when I open Firefox from a workspace that does not have a Firefox instance in it, I am either taken to a workspace with a Firefox instance or a new Firefox instance is launched.

How can I always launch a new instance, when there is none in the current workspace? Turning on the "Launch new instance" plugin in gnome-tweaks launches new instances even if there is an instance open in the current workspace.

Basically, when I open Firefox (or any application that is not fixed to a workspace), I want the following to happen:
Is there an instance running in the current workspace? -> Give focus to that instance
Otherwise, launch a new instance in the current workspace.

How can I achieve that?

What is the difference between "Try Ubuntu" and "Install Ubuntu" option?

I have VirtualBox on my Windows 10 and have downloaded Ubuntu ISO on my desktop.

I have configured the VirtualBox and provide Ubuntu ISO for Virtualbox. I get two options - "Try Ubuntu" and "Install Ubuntu". I am not sure which option to take.

My requirement is I want to run my Selenium scripts in parallel for which I need multiple machines, hence using VM.

If I select Install Ubuntu will it alter my laptop's file system? I intend to use VM temporarily to learn the concept of parallel script execution across multiple machines. Post learning I want to remove VirtualBox and don't want Ubuntu.

I want to open a PDF file multiple times with evince. I want to do this to be able to look at different sections of the same file at the same time. Every time I try to open the file again, it only brings up the already opened evince window with my PDF file. I also tried to open a new evince window and then opening my file by using the menu of evince.

Is there any possibility to do this?

Is there a proper way to run more than one tomcat instance on an Ubuntu server?

I've done some searching and found two options:

1. Download a zipped tomcat and manually deploy it. The obvious con is that it won't be upgraded using apt-get.
2. Use some advanced scripting, which is dangerous in a production server.

Any other ideas to cleanly run another instance?

Thanks in advance,

Adam