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https://issues.apache.org/jira/browse/HBASE-15085?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15091431#comment-15091431
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ramkrishna.s.vasudevan commented on HBASE-15085:
------------------------------------------------
Thanks for the patch and good catch
On the patch
{code}
// skip encoding to keep hfile meta consistent with data block info, see
HBASE-15085
929 if (Bytes.equals(key, HFileDataBlockEncoder.DATA_BLOCK_ENCODING)) {
930 return false;
931 }
{code}
When your REgion is already having DIFF as the encoding algo, then even if the
HFile is NONE encoded, then the writer that is created (HalfWriter) will be
having DIFF as its encoding and so the encoding would work correctly.
Same is the case when both Region is having DIFF and the HFile is also DIFF
encoded.
So before this patch - in both cases we were adding this DATA_BLOCK_ENCODING
key in two places - one from HFileDatablockEncoder.saveMetaData() and another
from this LoadIncrementalHfile code?
Now in the other case where your REgion has NONE and HFile has DIFF encoding -
then you are simply avoiding this DATA_BLOCK_ENCODING key itself so that the
HFile is not having any such fileinfo.
I think better to have test cases for all the above 3 conditions (assuming we
already have a test case for Region with NONE encoding and HFile with NONE
encoding).
Because after the patch in any of the above cases the LoadIncrementalHfile -
will not add the DATA_BLOCK_ENCODING at all.
> 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
> Labels: hfile
> Attachments: HBASE-15085-0.98-v1.patch, HBASE-15085-0.98-v2.patch,
> HBASE-15085-v1.patch, HBASE-15085-v2.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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