Run pipeline in UI stops when closing website

[leo-schick]

This is probably a known issue to many users using mara but I want to mention it here because I think this should not be that way:

When running a pipeline via the UI using run or run with upstreams it runs in a flask UI thread. This creates several issues:

• when you close the web page, the pipeline execution stops
• when the network connection breaks for just a short period of time (e.g. you disconnect your laptop from a docking station) it stops as well

In addition, when you run a pipeline via the server e.g. from a scheduled CI script or a cron job, you are not able to "connect" to the execution to see what is currently running. The only option to see what is going on is to open the node page and refresh it manually.