[
https://issues.apache.org/jira/browse/HBASE-11218?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14012128#comment-14012128
]
Andrew Purtell commented on HBASE-11218:
----------------------------------------
Let me look what might be needed to put back into 0.98 tomorrow
> Data loss in HBase standalone mode
> ----------------------------------
>
> Key: HBASE-11218
> URL: https://issues.apache.org/jira/browse/HBASE-11218
> Project: HBase
> Issue Type: Bug
> Reporter: Liu Shaohui
> Assignee: Liu Shaohui
> Fix For: 0.99.0
>
> Attachments: 11218v2.098.txt, HBASE-11218-trunk-v1.diff,
> HBASE-11218-trunk-v2.diff
>
>
> Data loss in HBase standalone mode.
> *How to produce it*
> # Start HBase standalone mode.
> # Create a table using hbase shell.
> # Scan '.META.' and you will find data in meta table
> # Kill the HBase process with -9 option
> # Start the HBase agaion
> # Scan '.META.' and you will find nothing in meta table.
> *There are three main reasons.*
> # FSDataOutputStream.sync should call flush() if the underlying wrapped
> stream is not Syncable. See HADOOP-8861
> # writeChecksum is ture in default LocalFileSystem and the
> ChecksumFSOutputSummer will buffer the data, which make the waledits are not
> written to os's filesystem with sync method immediately, and those edits will
> be lost in regionserver's failover.
> # The MiniZooKeeperCluster deletes the old zk data at startup which maye
> cause data loss in meta table. The failover procedure is: split pre root
> regionserver's hlog -> assign root -> split pre meta regionserver's hlog ->
> assign meta -> split all other regionservers' hlogs -> assign other regions.
> If there is no data in zookeeper, we will get null for root regionserver and
> then assign root table. Some data in root table maybe be lost for some root's
> WalEdits have not been splited and replayed. So does the Meta table.
> I finished the patch for 0.94 and am working on the patch for trunk.
> Suggestions are welcomed.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
