[ 
https://issues.apache.org/jira/browse/HADOOP-8292?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Alejandro Abdelnur updated HADOOP-8292:
---------------------------------------

    Status: Open  (was: Patch Available)

canceling patch for now as it may need more discussion.
                
> TableMapping does not refresh when topology is updated
> ------------------------------------------------------
>
>                 Key: HADOOP-8292
>                 URL: https://issues.apache.org/jira/browse/HADOOP-8292
>             Project: Hadoop Common
>          Issue Type: Bug
>    Affects Versions: 2.0.0-alpha
>            Reporter: Philip Zeyliger
>            Assignee: Alejandro Abdelnur
>         Attachments: HADOOP-8292.patch, HADOOP-8292.patch
>
>
> HADOOP-7030 introduced TableMapping, an implementation of DNSToSwitchMapping 
> which uses a file to map from IPs/hosts to their racks.  It's intended to 
> replace ScriptBasedMapping for cases where the latter was just a complicated 
> way of looking up the rack in a file.
> Though there was discussion of it on the JIRA, the TableMapping 
> implementation is not 'refreshable'.  i.e., if you want to add a host to your 
> cluster, and that host wasn't in the topology file to begin with, it will 
> never be added.
> TableMapping should refresh, either based on a command that can be executed, 
> or, perhaps, if the file on disk changes.
> I'll also point out that TableMapping extends CachedDNSToSwitchMapping, but, 
> since it does no refreshing, I don't see what the caching gets you: I think 
> the cache ends up being a second copy of the underlying map, always.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to