[FLINK-15094] Warning about using private constructor of java.nio.DirectByteBuffer in Java 11

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.10.1, 1.11.0
• Component/s: Runtime / Task
• Labels: pull-request-available
• Assignee: Andrey Zagrebin
• Reporter: Andrey Zagrebin
• Created: 06/Dec/19 09:02
• Updated: 05/May/20 12:15
• Resolved: 25/Feb/20 09:36

Description

The unsafe off-heap in FLINK-13985 was implemented by hacking into a private constructor of java.nio.DirectByteBuffer. This causes undesirable warnings in Java 11:

WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.apache.flink.core.memory.MemoryUtils (file:/C:/Development/repos/flink/flink-core/target/classes/) to constructor java.nio.DirectByteBuffer(long,int)
WARNING: Please consider reporting this to the maintainers of org.apache.flink.core.memory.MemoryUtils
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

We should look into this, confirm that it is harmless and try to silence it to avoid confusion for users.

Issue Links

• is caused by: FLINK-13985 Use unsafe memory for managed memory.
• relates to: FLINK-17524 Remove "An illegal reflective access operation has occurred" warnings on JDK11
• links to: GitHub Pull Request #11160