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https://issues.apache.org/jira/browse/HBASE-27519?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17645547#comment-17645547
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chenglei edited comment on HBASE-27519 at 12/10/22 4:52 AM:
------------------------------------------------------------
Pushed to 2.4+, thanks [~wchevreuil] for reviewing!
was (Author: comnetwork):
pushed to 2.4+, thanks [~wchevreuil] for reviewing!
> Another case for FNFE on StoreFileScanner after a flush followed by a
> compaction
> --------------------------------------------------------------------------------
>
> Key: HBASE-27519
> URL: https://issues.apache.org/jira/browse/HBASE-27519
> Project: HBase
> Issue Type: Bug
> Affects Versions: 2.6.0, 3.0.0-alpha-3, 2.4.15, 2.5.2
> Reporter: chenglei
> Assignee: chenglei
> Priority: Major
>
> Besides the fix for {{HStore.getScanners}} for FNFE on StoreFileScanner after
> a flush followed by a compaction in HBASE-27484, there is a another case
> would cause FNFE:
> # When {{StoreScanner}} is scanning, there is a flush followed by a
> compaction. When the flushed is completed in {{HStore.completeFlush}} and
> after it adds the new {{HStoreFile}} in {{StoreEngine}}, it would notify the
> {{StoreScanner.updateReaders}} by {{HStore.notifyChangedReadersObservers}}
> with the new flushed {{HStoreFile}}：
> {code:java}
> private boolean completeFlush(List<HStoreFile> sfs, long snapshotId)
> throws IOException {
> // NOTE:we should keep clearSnapshot method inside the write lock because
> clearSnapshot may
> // close {@link DefaultMemStore#snapshot}, which may be used by
> // {@link DefaultMemStore#getScanners}.
> storeEngine.addStoreFiles(sfs,
> snapshotId > 0 ? () -> this.memstore.clearSnapshot(snapshotId) : () -> {
> });
> // notify to be called here - only in case of flushes
> notifyChangedReadersObservers(sfs);
> if (LOG.isTraceEnabled()) {
> long totalSize = getTotalSize(sfs);
> String traceMessage = "FLUSH time,count,size,store size,store files ["
> + EnvironmentEdgeManager.currentTime() + "," + sfs.size() + "," +
> totalSize + ","
> + storeSize + "," +
> storeEngine.getStoreFileManager().getStorefileCount() + "]";
> LOG.trace(traceMessage);
> }
> return needsCompaction();
> }
> {code}
> # But if before entering {{StoreScanner.updateReaders}} , the compaction task
> starts and it compacts the new flushed {{HStoreFile}} and then
> {{HStore.closeAndArchiveCompactedFiles}} is called by
> {{CompactedHFilesDischarger}} to delete the {{HStoreFile}}.
> # When {{StoreScanner.updateReaders}} continues to execute, it would read
> already deleted {{HStoreFile}} and throws FNFE.
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