CASSANDRA-21182 - Fix flaky DTest: largecolumn_test.TestLargeColumn#286
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CASSANDRA-21182 - Fix flaky DTest: largecolumn_test.TestLargeColumn#286samueldlightfoot wants to merge 1 commit intoapache:trunkfrom
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Generational ZGC (JDK 21 default) only processes PhantomReferences during major collections, which may not trigger during short test runs. This causes DirectByteBuffer Cleaners to not fire, leaving ~63MB of stale direct memory that inflates TOTAL_CAPACITY and fails the assertion. Force System.gc() via nodetool before each measurement to ensure a major collection runs and reference processing completes.
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Force GC before direct memory measurements for ZGC compatibility
Generational ZGC (JDK 21 default) only processes PhantomReferences during major collections, which may not trigger during short test runs. This causes DirectByteBuffer Cleaners to not fire, leaving ~63MB of stale direct memory that inflates TOTAL_CAPACITY and fails the assertion.
Force System.gc() via nodetool before each measurement to ensure a major collection runs and reference processing completes.
CASSANDRA-21182