What does the Spark UI indicator light in the light blue portion of the progress bar indicate?

Question

Below is a screenshot of the Apache Spark interface showing the progress of step 0. The blue and cyan sections of the progress bar are in the Tasks column. The blue part corresponds to the number of completed tasks [1075/3200 in the screenshot below].

What does the light blue portion of the progress bar indicate? Thanks!

Answer 1

• The overall panel size is a series of tasks for this phase.
• the dark blue part of the part represents already completed tasks
• the light blue part of the panel represents the currently running tasks