This problem surfaced in impala integration tests
IMPALA-11592. TestLocalCatalogRetries.test_fetch_metadata_retry fails in S3 build
after the change
HADOOP-17461. Add thread-level IOStatistics Context
The actual GC race condition came with
HADOOP-18091. S3A auditing leaks memory through ThreadLocal references
The fix for this is, if our hypothesis is correct, in WeakReferenceMap.create()
where a strong reference to the new value is kept in a local variable
*and referred to later* so that the JVM will not GC it.
Along with the fix, extra assertions ensure that if the problem is not fixed,
applications will fail faster/more meaningfully.
Contributed by Steve Loughran.
af0a6d7987