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https://issues.apache.org/jira/browse/HBASE-15085?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15093634#comment-15093634
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Victor Xu commented on HBASE-15085:
-----------------------------------
Thanks for your question.
If there is region cross over, the bulk load process could generate two
splitted hfile directly with DBE defined by the table.
If there is no region cross over, the bulk loaded hfile would keep its DBE
while the table has none. Sooner or later, major compaction can make them
match.
Thus, It is eventual consistent.
Even if there is no major compaction (by any reason), the hfile should be
scan/get without any exception caused by this kind of DBE mismatch.
> IllegalStateException was thrown when scanning on bulkloaded HFiles
> -------------------------------------------------------------------
>
> Key: HBASE-15085
> URL: https://issues.apache.org/jira/browse/HBASE-15085
> Project: HBase
> Issue Type: Bug
> Affects Versions: 0.98.12, 1.1.2
> Environment: HBase-0.98.12 & Hadoop-2.6.0 & JDK1.7
> HBase-1.1.2 & Hadoop-2.6.0 & JDK1.7
> Reporter: Victor Xu
> Assignee: Victor Xu
> Priority: Critical
> Labels: hfile
> Fix For: 2.0.0, 1.2.0, 1.3.0, 1.1.3, 0.98.17, 1.0.4
>
> Attachments: HBASE-15085-0.98-v1.patch, HBASE-15085-0.98-v2.patch,
> HBASE-15085-0.98-v3.patch, HBASE-15085-0.98-v4.patch,
> HBASE-15085-0.98-v4.patch, HBASE-15085-0.98-v5.patch,
> HBASE-15085-branch-1.0-v1.patch, HBASE-15085-branch-1.0-v2.patch,
> HBASE-15085-branch-1.1-v1.patch, HBASE-15085-branch-1.1-v2.patch,
> HBASE-15085-branch-1.2-v1.patch, HBASE-15085-branch-1.2-v2.patch,
> HBASE-15085-v1.patch, HBASE-15085-v2.patch, HBASE-15085-v3.patch,
> HBASE-15085-v4.patch, HBASE-15085-v4.patch, HBASE-15085-v4.patch,
> HBASE-15085-v4.patch, HBASE-15085-v5.patch
>
>
> IllegalStateException was thrown when we scanned from an HFile which was bulk
> loaded several minutes ago, as shown below:
> {code}
> 2015-12-16 22:20:54,456 ERROR
> com.taobao.kart.coprocessor.server.KartCoprocessor:
> icbu_ae_ws_product,/0055,1450275490479.6a6a700f465ad074287fed720c950f7c.
> batchNotify exception
> java.lang.IllegalStateException: EncodedScanner works only on encoded data
> blocks
> at
> org.apache.hadoop.hbase.io.hfile.HFileReaderV2$EncodedScannerV2.updateCurrentBlock(HFileReaderV2.java:1042)
> at
> org.apache.hadoop.hbase.io.hfile.HFileReaderV2$EncodedScannerV2.seekTo(HFileReaderV2.java:1093)
> at
> org.apache.hadoop.hbase.regionserver.StoreFileScanner.seekAtOrAfter(StoreFileScanner.java:244)
> at
> org.apache.hadoop.hbase.regionserver.StoreFileScanner.seek(StoreFileScanner.java:152)
> at
> org.apache.hadoop.hbase.regionserver.StoreScanner.seekScanners(StoreScanner.java:329)
> at
> org.apache.hadoop.hbase.regionserver.StoreScanner.<init>(StoreScanner.java:188)
> at
> org.apache.hadoop.hbase.regionserver.HStore.getScanner(HStore.java:1879)
> at
> org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.<init>(HRegion.java:4068)
> at
> org.apache.hadoop.hbase.regionserver.HRegion.instantiateRegionScanner(HRegion.java:2029)
> at
> org.apache.hadoop.hbase.regionserver.HRegion.getScanner(HRegion.java:2015)
> at
> org.apache.hadoop.hbase.regionserver.HRegion.getScanner(HRegion.java:1992)
> {code}
> I used 'hbase hfile' command to analyse the meta and block info of the hfile,
> finding that even through the DATA_BLOCK_ENCODING was 'DIFF' in FileInfo, the
> actual data blocks was written without any encoding algorithms(BlockType was
> 'DATA', not 'ENCODED_DATA'):
> {code}
> Fileinfo:
> BLOOM_FILTER_TYPE = ROW
> BULKLOAD_SOURCE_TASK = attempt_1442077249005_606706_r_000012_0
> BULKLOAD_TIMESTAMP = \x00\x00\x01R\x12$\x13\x12
> DATA_BLOCK_ENCODING = DIFF
> ...
> DataBlock Header:
> HFileBlock [ fileOffset=0 headerSize()=33 blockType=DATA
> onDiskSizeWithoutHeader=65591 uncompressedSizeWithoutHeader=65571
> prevBlockOffset=-1 isUseHBaseChecksum()=true checksumType=CRC32
> bytesPerChecksum=16384 onDiskDataSizeWithHeader=65604
> getOnDiskSizeWithHeader()=65624 totalChecksumBytes()=20 isUnpacked()=true
> buf=[ java.nio.HeapByteBuffer[pos=0 lim=65624 cap=65657],
> array().length=65657, arrayOffset()=0 ]
> dataBeginsWith=\x00\x00\x003\x00\x00\x00\x0A\x00\x10/0008:1000000008\x01dprod
> fileContext=HFileContext [ usesHBaseChecksum=true checksumType=CRC32
> bytesPerChecksum=16384 blocksize=65536 encoding=NONE includesMvcc=true
> includesTags=false compressAlgo=NONE compressTags=false cryptoContext=[
> cipher=NONE keyHash=NONE ] ] ]
> {code}
> The data block encoding in file info was not consistent with the one in data
> block, which means there must be something wrong with the bulkload process.
> After debugging on each step of bulkload, I found that LoadIncrementalHFiles
> had a bug when loading hfile into a splitted region.
> {code}
> /**
> * Copy half of an HFile into a new HFile.
> */
> private static void copyHFileHalf(
> Configuration conf, Path inFile, Path outFile, Reference reference,
> HColumnDescriptor familyDescriptor)
> throws IOException {
> FileSystem fs = inFile.getFileSystem(conf);
> CacheConfig cacheConf = new CacheConfig(conf);
> HalfStoreFileReader halfReader = null;
> StoreFile.Writer halfWriter = null;
> try {
> halfReader = new HalfStoreFileReader(fs, inFile, cacheConf, reference,
> conf);
> Map<byte[], byte[]> fileInfo = halfReader.loadFileInfo();
> int blocksize = familyDescriptor.getBlocksize();
> Algorithm compression = familyDescriptor.getCompression();
> BloomType bloomFilterType = familyDescriptor.getBloomFilterType();
> // use CF's DATA_BLOCK_ENCODING to initialize HFile writer
> HFileContext hFileContext = new HFileContextBuilder()
> .withCompression(compression)
>
> .withChecksumType(HStore.getChecksumType(conf))
>
> .withBytesPerCheckSum(HStore.getBytesPerChecksum(conf))
> .withBlockSize(blocksize)
>
> .withDataBlockEncoding(familyDescriptor.getDataBlockEncoding())
> .build();
> halfWriter = new StoreFile.WriterBuilder(conf, cacheConf,
> fs)
> .withFilePath(outFile)
> .withBloomType(bloomFilterType)
> .withFileContext(hFileContext)
> .build();
> HFileScanner scanner = halfReader.getScanner(false, false, false);
> scanner.seekTo();
> do {
> KeyValue kv = KeyValueUtil.ensureKeyValue(scanner.getKeyValue());
> halfWriter.append(kv);
> } while (scanner.next());
> // force encoding setting with the original HFile's file info
> for (Map.Entry<byte[],byte[]> entry : fileInfo.entrySet()) {
> if (shouldCopyHFileMetaKey(entry.getKey())) {
> halfWriter.appendFileInfo(entry.getKey(), entry.getValue());
> }
> }
> } finally {
> if (halfWriter != null) halfWriter.close();
> if (halfReader != null)
> halfReader.close(cacheConf.shouldEvictOnClose());
> }
> }
> {code}
> As shown above, when an HFile which has a DIFF encoding is bulkloaded into a
> splitted region whose CF's DATA_BLOCK_ENCODING is NONE, the two new HFiles
> would have inconsistent encodings.
> Besides, it would be OK if splitting region's DATA_BLOCK_ENCODING is DIFF and
> bulk loaded HFile has NONE, because the initial bulkloaded HFile would not
> write the encoding info into its meta (NoOpDataBlockEncoder.saveMetadata() is
> empty), and It then would not rewrite encoding in two generated Files in
> copyHFileHalf(). Two new HFiles' meta info would be consistent with their
> block headers, which would all be DIFF. So, no Exception would be thrown when
> scanning these files.
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