Deep Dive into Monitoring Spark Applications Using Web UI and SparkListeners (Jacek Laskowski) 

This was just an excellent presentation, dziekuje bardzo (thanks Jacek)! I can also highly recommend Jacek's Mastering Spark 2.0 gitbook, it is going to become a standard reference for my team.

Thank you so much. This is a great explanation after you got confused reading spark source code directly

Thanks for pointing out something that is potentially useful for debug and performance tuning, and is easily ignored by beginners. Appreciated your contribution on Mastering Apache Spark book.

Great presentation! very clear and informative! thank you

Awesome. Thank you.

Thank you :)