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https://issues.apache.org/jira/browse/HBASE-22324?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16835374#comment-16835374
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chenyang commented on HBASE-22324:
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submit 0006.patch to close store, region and wal in TestMemStoreSegmentsIterator
> loss a mass of data when the sequenceId of cells greater than Integer.Max,
> because MemStoreMergerSegmentsIterator can not merge segments
> ------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: HBASE-22324
> URL: https://issues.apache.org/jira/browse/HBASE-22324
> Project: HBase
> Issue Type: Bug
> Components: in-memory-compaction
> Affects Versions: 2.1.0, 2.2.0
> Reporter: chenyang
> Priority: Blocker
> Labels: patch
> Fix For: 2.1.0
>
> Attachments: HBASE-22324.branch-2.1.0005.patch,
> HBASE-22324.branch-2.1.0006.patch
>
>
> if your memstore type is CompactingMemStore，MemStoreMergerSegmentsIterator
> can not merge memstore segments when the seqId of cells greater than
> Integer.Max, as a result, lossing a mass of data. the reason is that
> MemStoreMergerSegmentsIterator use Integer.Max as readPt when create Scanner,
> but the seqId of cell may be greater than Integer.MAX_VALUE, it`s type is
> long. code as below:
> {code:java}
> public MemStoreMergerSegmentsIterator(List<ImmutableSegment> segments,
> CellComparator comparator,
> int compactionKVMax) throws IOException {
> super(compactionKVMax);
> // create the list of scanners to traverse over all the data
> // no dirty reads here as these are immutable segments
> AbstractMemStore.addToScanners(segments, Integer.MAX_VALUE, scanners);
> //bug, should use Long.MAX_VALUE
> heap = new KeyValueHeap(scanners, comparator);
> }
> SegmentScanner.java code as below
> protected void updateCurrent() {
> Cell startKV = current;
> Cell next = null;
> try {
> while (iter.hasNext()) {
> next = iter.next();
> // here, if seqId>readPoint(Integer.MAX_VALUE), never read cell, as a
> result, lossing lots of cells
> if (next.getSequenceId() <= this.readPoint) {
> current = next;
> return;// skip irrelevant versions
> }
> if (stopSkippingKVsIfNextRow && // for backwardSeek() stay in the
> startKV != null && // boundaries of a single row
> segment.compareRows(next, startKV) > 0) {
> current = null;
> return;
> }
> } // end of while
> current = null; // nothing found
> } finally {
> if (next != null) {
> // in all cases, remember the last KV we iterated to, needed for
> reseek()
> last = next;
> }
> }
> }
> MemStoreCompactorSegmentsIterator has the same bug
> public MemStoreCompactorSegmentsIterator(List<ImmutableSegment> segments,
> CellComparator comparator, int compactionKVMax, HStore store) throws
> IOException {
> super(compactionKVMax);
> List<KeyValueScanner> scanners = new ArrayList<KeyValueScanner>();
> AbstractMemStore.addToScanners(segments, Integer.MAX_VALUE, scanners);
> //bug, should use Long.MAX_VALUE
> // build the scanner based on Query Matcher
> // reinitialize the compacting scanner for each instance of iterator
> compactingScanner = createScanner(store, scanners);
> refillKVS();
> }{code}
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