HBASE-30038: RefCnt Leak error when caching#7995
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dParikesit wants to merge 2 commits intoapache:masterfrom
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HBASE-30038: RefCnt Leak error when caching#7995dParikesit wants to merge 2 commits intoapache:masterfrom
dParikesit wants to merge 2 commits intoapache:masterfrom
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wchevreuil
approved these changes
Mar 28, 2026
vaijosh
reviewed
Mar 30, 2026
| Mockito.verify(cache, Mockito.never()).cacheBlock(Mockito.any(), Mockito.any(), | ||
| Mockito.anyBoolean(), Mockito.anyBoolean()); | ||
| System.gc(); | ||
| Thread.sleep(1000); |
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@dParikesit
I think the 1-second assumption might bite us on slower systems and make the test flaky.
What if we wrap this in a loop instead? We could retry up to 15 times with a small delay—that way it succeeds as soon as it's ready rather than relying on luck.
vaijosh
reviewed
Mar 30, 2026
| writeDataBlocksAndCreateIndex(hbw, outputStream, biw); | ||
| assertTrue(biw.getNumLevels() >= 3); | ||
| System.gc(); | ||
| Thread.sleep(1000); |
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@dParikesit
I think the 1-second assumption might bite us on slower systems and make the test flaky.
What if we wrap this in a loop instead? We could retry up to 15 times with a small delay—that way it succeeds as soon as it's ready rather than relying on luck.
Contributor
|
Please consider @vaijosh suggestions and also fix spotless issues. |
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Author
|
Thanks for the suggestions. I'll get back to you after I fix it. |
pankaj72981
approved these changes
Mar 30, 2026
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JIRA: HBASE-30038
This bug is similar to HBASE-28890
HFileBlock.Writer.getBlockForCaching() creates a ref-counted HFileBlock, and the caller must release its own reference after the cache has taken the ownership it needs.
In HFileWriterImpl.java, the leak happened when shouldCacheBlock() returned before cacheFormatBlock.release() ran.
In HFileBlockIndex.java, the intermediate-index path cached blockForCaching but never released the reference at all.
Because these blocks can be backed by pooled off-heap ByteBuffs, repeated HFile writes could steadily drain allocator buffers and effectively leak memory, even though the blocks were only meant to live long enough to be considered for cache-on-write.