[
https://issues.apache.org/jira/browse/HBASE-810?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12621519#action_12621519
]
stack commented on HBASE-810:
-----------------------------
I don't think so Sebastien. A TableSplit is defined by a start and end row.
On MR job setup, these correspond to region demarcations. If the region splits
during the subsequent MR job, and the map fails and then reruns, it'll scan the
two daughters since the map tasks TableSplit spans the two regions.
> Prevent temporary deadlocks when, during a scan with write operations, the
> region splits
> ----------------------------------------------------------------------------------------
>
> Key: HBASE-810
> URL: https://issues.apache.org/jira/browse/HBASE-810
> Project: Hadoop HBase
> Issue Type: Bug
> Affects Versions: 0.2.0
> Reporter: Jean-Daniel Cryans
> Priority: Minor
> Fix For: 0.2.1, 0.3.0
>
>
> HBASE-804 was not about the good problem, this one is. Anyone that iterates
> through the results of a scanner and that rewrites data back into the row at
> each iteration will hit a UnknownScannerException if a split occurs. See the
> stack in the referred jira. Timeline :
> Split occurs, acquires a write lock and waits for scanners to finish
> The scanner in the custom code iterates and writes data until the write is
> blocked by the lock
> deadlock
> The scanner timeouts thus the region splits but the USE will be thrown when
> next() is called
> Inside a Map, the task will simply be retried when the first one fails.
> Elsewhere, it becomes more complicated.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
