[
https://issues.apache.org/jira/browse/HBASE-2643?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12897748#action_12897748
]
stack commented on HBASE-2643:
------------------------------
Good stuff Richard. If a runtime exception splitting logs, we should fail to
start the cluster? It means likely dataloss. Or, there is a flag in hbase now
-- its in the splitlog stuff -- IIRC which says fail-if-any-error OR
try-and=keep-going across errors. If this flag is set, we should catch the
RuntimeException, log it and not start the master. Otherwise, we should log
the exception and then let the master proceed.
> Figure how to deal with eof splitting logs
> ------------------------------------------
>
> Key: HBASE-2643
> URL: https://issues.apache.org/jira/browse/HBASE-2643
> Project: HBase
> Issue Type: Bug
> Reporter: stack
> Priority: Blocker
> Fix For: 0.90.0
>
>
> When splitting the WAL and encountering EOF, it's not clear what to do.
> Initial discussion of this started in http://review.hbase.org/r/74/ -
> summarizing here for brevity:
> We can get an EOFException while splitting the WAL in the following cases:
> - The writer died after creating the file but before even writing the header
> (or crashed halfway through writing the header)
> - The writer died in the middle of flushing some data - sync() guarantees
> that we can see _at least_ the last edit, but we may see half of an edit that
> was being written out when the RS crashed (especially for large rows)
> - The data was actually corrupted somehow (eg a length field got changed to
> be too long and thus points past EOF)
> Ideally we would know when we see EOF whether it was really the last record,
> and in that case, simply drop that record (it wasn't synced, so therefore we
> dont need to split it). Some open questions:
> - Currently we ignore empty files. Is it ok to ignore an empty log file if
> it's not the last one?
> - Similarly, do we ignore an EOF mid-record if it's not the last log file?
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
