CASSANDRA-9861, a change was added to enable collecting heap dumps by default if the process encountered an OOM error. These heap dumps are stored in the Apache Cassandra home directory unless configured otherwise (see Cassandra Support Document for this feature).
The creation and storage of heap dumps aides debugging and investigative workflows, but is not be desirable for a production environment where these heap dumps may occupy a large amount of disk space and require manual intervention for cleanups.
Managing heap dumps on out of memory errors and configuring the paths for these heap dumps are available as JVM options in JVM. The current behavior conflicts with the Boolean JVM flag HeapDumpOnOutOfMemoryError.
A patch can be proposed here that would make the heap dump on OOM error honor the HeapDumpOnOutOfMemoryError flag. Users who would want to still generate heap dumps on OOM errors can set the -XX:+HeapDumpOnOutOfMemoryError JVM option.