What does "red" executors in the Spark UI mean?

Question

I ran a Spark Job and looked at the results on the history server. Some of the executors are marked as red; They were not killed. What do the red ones mean?

My first thought was that these were the ones that took longer, but ID 16 is marked in red and 15 took longer (2.2h (12min)) but it's not marked red.

So what does the red indicate?

Answer 1

If 10% or more of the task time is used up for Garbage Collection then those executors are marked as red.