[jira] [Comment Edited] (HBASE-20403) Prefetch sometimes doesn't work with encrypted file system

["Umesh Agashe (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HBASE-20403?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16436397#comment-16436397 ] 

Umesh Agashe edited comment on HBASE-20403 at 4/12/18 10:26 PM:
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Its possible. AFAIK, there is an optimization in the HBase code where we try to optimize an extra seek by reading next block's header while reading the current block. As header size when encrypted/ not encrypted may be different, its possible that HBase is trying to read more than the buffer size. Needs more digging in.


was (Author: uagashe):
Its possible. AFAIK, there is an optimization in the HBase code where we try to optimize an extra seek by reading next block's header while reading the current block. As header size when encrypted/ not encrypted may be different, its possible that HBase is trying to read more than the buffer size.

> Prefetch sometimes doesn't work with encrypted file system
> ----------------------------------------------------------
>
>                 Key: HBASE-20403
>                 URL: https://issues.apache.org/jira/browse/HBASE-20403
>             Project: HBase
>          Issue Type: Bug
>    Affects Versions: 2.0.0-beta-2
>            Reporter: Umesh Agashe
>            Priority: Major
>             Fix For: 2.0.0
>
>
> Log from long running test has following stack trace a few times:
> {code}
> 2018-04-09 18:33:21,523 WARN org.apache.hadoop.hbase.io.hfile.HFileReaderImpl: Prefetch path=hdfs://ns1/hbase/data/default/IntegrationTestBigLinkedList_20180409172704/35f1a7ef13b9d327665228abdbcdffae/meta/9089d98b2a6b4847b3fcf6aceb124988, offset=36884200, end=231005989
> java.lang.IllegalArgumentException
>   at java.nio.Buffer.limit(Buffer.java:275)
>   at org.apache.hadoop.hdfs.ByteBufferStrategy.readFromBlock(ReaderStrategy.java:183)
>   at org.apache.hadoop.hdfs.DFSInputStream.readBuffer(DFSInputStream.java:705)
>   at org.apache.hadoop.hdfs.DFSInputStream.readWithStrategy(DFSInputStream.java:766)
>   at org.apache.hadoop.hdfs.DFSInputStream.read(DFSInputStream.java:831)
>   at org.apache.hadoop.crypto.CryptoInputStream.read(CryptoInputStream.java:197)
>   at java.io.DataInputStream.read(DataInputStream.java:149)
>   at org.apache.hadoop.hbase.io.hfile.HFileBlock.readWithExtra(HFileBlock.java:762)
>   at org.apache.hadoop.hbase.io.hfile.HFileBlock$FSReaderImpl.readAtOffset(HFileBlock.java:1559)
>   at org.apache.hadoop.hbase.io.hfile.HFileBlock$FSReaderImpl.readBlockDataInternal(HFileBlock.java:1771)
>   at org.apache.hadoop.hbase.io.hfile.HFileBlock$FSReaderImpl.readBlockData(HFileBlock.java:1594)
>   at org.apache.hadoop.hbase.io.hfile.HFileReaderImpl.readBlock(HFileReaderImpl.java:1488)
>   at org.apache.hadoop.hbase.io.hfile.HFileReaderImpl$1.run(HFileReaderImpl.java:278)
>   at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
>   at java.util.concurrent.FutureTask.run(FutureTask.java:266)
>   at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
>   at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
>   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
>   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
>   at java.lang.Thread.run(Thread.java:748)
> {code}
> Size on disk calculations seem to get messed up due to encryption. Possible fixes can be:
> * if file is encrypted with FileStatus#isEncrypted() and do not prefetch.
> * document that hbase.rs.prefetchblocksonopen cannot be true if file is encrypted.



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