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https://issues.apache.org/jira/browse/HBASE-11218?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14006979#comment-14006979
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Liu Shaohui commented on HBASE-11218:
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[~nkeywal]
{quote}
I'm curious, why is it an issue for you?
{quote}
We use the standalone hbase in our onebox test env. In this env, we start the
application and other services (eg, hbase, zookeeper) that it depends on in a
machine, , then do many end-to-end logical and failure tests. So it is
important to keep data durability in some level. Data loss in standalone mode
give a not good impression of HBase to out users.
{quote}
On the patch, will this slow down the tests?
{quote}
I will do a comparison and show the data later.
> 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: HBASE-11218-trunk-v1.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.
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