Spark 2.4.2 is a maintenance release containing stability fixes. This release is based on the branch-2.4 maintenance branch of Spark. We strongly recommend all 2.4 users to upgrade to this stable release.
Note that Scala 2.11 support is deprecated from 2.4.1 onwards. As of 2.4.2, the pre-built convenience binaries are compiled for Scala 2.12. Spark is still cross-published for 2.11 and 2.12 in Maven Central, and can be built for 2.11 from source.
spark.executor.heartbeatIntervalto a value less than 1 seconds, it will always fail because the value will be converted to 0 and the heartbeat will always timeout and finally kill the executor.
You can consult JIRA for the detailed changes.
We would like to acknowledge all community members for contributing patches to this release.