[SPARK-21181] Suppress memory leak errors reported by netty

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.1.0
• Fix Version/s: 2.1.2, 2.2.0, 2.3.0
• Component/s: Input/Output
• Assignee: Dhruve Ashar
• Reporter: Dhruve Ashar
• Created: 22/Jun/17 16:23
• Updated: 30/Aug/19 21:43
• Resolved: 23/Jun/17 17:37

Description

We are seeing netty report memory leak erros like the one below after switching to 2.1.

ERROR ResourceLeakDetector: LEAK: ByteBuf.release() was not called before it's garbage-collected. Enable advanced leak reporting to find out where the leak occurred. To enable advanced leak reporting, specify the JVM option '-Dio.netty.leakDetection.level=advanced' or call ResourceLeakDetector.setLevel() See http://netty.io/wiki/reference-counted-objects.html for more information.

Looking a bit deeper, Spark is not leaking any memory here, but it is confusing for the user to see the error message in the driver logs.

After enabling, '-Dio.netty.leakDetection.level=advanced', netty reveals the SparkSaslServer to be the source of these leaks.

Sample trace :https://gist.github.com/dhruve/b299ebc35aa0a185c244a0468927daf1

Issue Links

• links to: [Github] Pull Request #18392 (dhruve)
• links to: [Github] Pull Request #18407 (dhruve)