[jira] [Commented] (HBASE-3686) Scanner timeout on RegionServer but Client won't know what happened

["stack (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HBASE-3686?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13010158#comment-13010158 ] 

stack commented on HBASE-3686:
------------------------------

@Sean Does this happen with default configs?  Or was it result of local customizations?  Thanks.  Maybe we should return a better message in the UnknownScannerException too?  Or, should Scan tell server the lease period to use -- as you suggest.  That seems like best fix.

> Scanner timeout on RegionServer but Client won't know what happened
> -------------------------------------------------------------------
>
>                 Key: HBASE-3686
>                 URL: https://issues.apache.org/jira/browse/HBASE-3686
>             Project: HBase
>          Issue Type: Bug
>          Components: client
>    Affects Versions: 0.89.20100924
>            Reporter: Sean Sechrist
>            Priority: Minor
>
> This can cause rows to be lost from a scan.
> See this thread where the issue was brought up: http://search-hadoop.com/m/xITBQ136xGJ1
> If hbase.regionserver.lease.period is higher on the client than the server we can get this series of events: 
> 1. Client is scanning along happily, and does something slow.
> 2. Scanner times out on region server
> 3. Client calls HTable.ClientScanner.next()
> 4. The region server throws an UnknownScannerException
> 5. Client catches exception and sees that it's not longer then it's hbase.regionserver.lease.period config, so it doesn't throw a ScannerTimeoutException. Instead, it treats it like a NSRE.
> Right now the workaround is to make sure the configs are consistent. 
> A possible fix would be to use whatever the region server's scanner timeout is, rather than the local one.

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira