[Spark Streaming] Are SparkListener/StreamingListener callbacks called concurrently?

[Majid Azimi <ma...@protonmail.com.INVALID>]

Hi,

What is the concurrency model behind SparkListener or StreamingListener callbacks?
1. Multiple threads might access callbacks simultaneously.
2. Callbacks are guaranteed to be executed by a single thread.(Thread ids might change on consecutive calls, though)

I asked the same question on stackoverflow, and waited for about one day. Since there was no response, I'm reposting it here.

https://stackoverflow.com/questions/50921585/are-sparklistener-streaminglistener-callbacks-called-concurrently