[SPARK-31373] Cluster tried to fetch blocks from blacklisted node of previous stage

• Type: Question
• Status: Resolved
• Priority: Major
• Resolution: Invalid
• Affects Version/s: 2.4.2
• Component/s: Block Manager, Spark Core

Environment

EMR cluster with r5.4xlarge and r5.8xlarge instances

• Assignee: Unassigned
• Reporter: Yuchen Feng
• Created: 07/Apr/20 09:16
• Updated: 12/Dec/22 18:10
• Resolved: 13/Apr/20 04:59

Description

We enabled blacklist on our Spark application but recently we saw some wierd issue.

Our code is like
  rdd.repartitions(...).mapPartitions(...).groupByKey(...).map().collect()
In mapPartitions stage, some executors has exception "Can't connect to host xxxxxx: Connection rest by peer" and tasks on them were failed, so all executors under this node were blacklisted, as well as this node. These executors did complete some tasks before blacklisted.

Then in next stage (groupByKey(...).map()), application failed with block fetch failure: IndexOutOfBound Exception when some healthy executor want to fetch block from one of above blacklisted executors.

It happened multiple times.