Wei Zheng created HIVE-11467:
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Summary: WriteBuffers rounding wbSize to next power of 2 may cause
OOM
Key: HIVE-11467
URL: https://issues.apache.org/jira/browse/HIVE-11467
Project: Hive
Issue Type: Bug
Components: Hive
Affects Versions: 1.2.0, 2.0.0
Reporter: Wei Zheng
Assignee: Wei Zheng
If wbSize passed to WriteBuffers cstr is not power of 2, it will do a rounding
first to the next power of 2
{code}
public WriteBuffers(int wbSize, long maxSize) {
this.wbSize = Integer.bitCount(wbSize) == 1 ? wbSize :
(Integer.highestOneBit(wbSize) << 1);
this.wbSizeLog2 = 31 - Integer.numberOfLeadingZeros(this.wbSize);
this.offsetMask = this.wbSize - 1;
this.maxSize = maxSize;
writePos.bufferIndex = -1;
nextBufferToWrite();
}
{code}
That may break existing memory consumption assumption for mapjoin, and
potentially cause OOM.
The solution will be to pass a power of 2 number as wbSize from upstream during
hashtable creation, to avoid this late expansion.
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