hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Sean Busbey (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HBASE-11660) Make WAL reader follow contract for java.io.InputStream.available()
Date Mon, 04 Aug 2014 17:26:12 GMT

    [ https://issues.apache.org/jira/browse/HBASE-11660?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14084925#comment-14084925
] 

Sean Busbey commented on HBASE-11660:
-------------------------------------

I don't think those code paths test for the case where the stream for the WAL returns 0 bytes
available when it is not at EOF, though. That kind of test is the best way to ensure that
as the code base changes we keep accounting for the correct InputStream behavior.

> Make WAL reader follow contract for java.io.InputStream.available()
> -------------------------------------------------------------------
>
>                 Key: HBASE-11660
>                 URL: https://issues.apache.org/jira/browse/HBASE-11660
>             Project: HBase
>          Issue Type: Bug
>          Components: wal
>            Reporter: Eric Hanson
>            Priority: Minor
>         Attachments: hbase-11660.01.patch
>
>
> In the process of building support to running HBase on Microsoft Azure HDInsight, I hit
an issue in the HBase WAL reading process that took a lot of time to debug. The WAL reading
code depends on available() for the log InputStream never returing 0 until end of file. This
is not the same as the contract in java.io.InputStream for available. 
> To prevent future grief for others that may want to port HBase onto storage systems other
than HDFS, I propose to change the HBase WAL reader so it does not assume that EOF has been
reached when available() == 0. It instead would treat available only as described in InputStream,
i.e. available() is merely the number of bytes that could be read from the stream without
blocking. That could be 0 even before EOF.



--
This message was sent by Atlassian JIRA
(v6.2#6252)

Mime
View raw message