[ 
https://issues.apache.org/jira/browse/HBASE-6295?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13686790#comment-13686790
 ] 

Eric Newton commented on HBASE-6295:
------------------------------------

[~nkeywal] Using the accumulo batch scanner, a single client will group 
requests by server: queries to multiple ranges on the same node will be sent in 
a single request to the node. If the number of client query threads is greater 
than the number of nodes, multiple threads may be used. The BatchWriter, 
however, will only use one thread to write to any one server.
                
> Possible performance improvement in client batch operations: presplit and 
> send in background
> --------------------------------------------------------------------------------------------
>
>                 Key: HBASE-6295
>                 URL: https://issues.apache.org/jira/browse/HBASE-6295
>             Project: HBase
>          Issue Type: Improvement
>          Components: Client, Performance
>    Affects Versions: 0.95.2
>            Reporter: Nicolas Liochon
>            Assignee: Nicolas Liochon
>              Labels: noob
>             Fix For: 0.98.0
>
>         Attachments: 6295.v11.patch, 6295.v12.patch, 6295.v14.patch, 
> 6295.v1.patch, 6295.v2.patch, 6295.v3.patch, 6295.v4.patch, 6295.v5.patch, 
> 6295.v6.patch, 6295.v8.patch, 6295.v9.patch
>
>
> today batch algo is:
> {noformat}
> for Operation o: List<Op>{
>   add o to todolist
>   if todolist > maxsize or o last in list
>     split todolist per location
>     send split lists to region servers
>     clear todolist
>     wait
> }
> {noformat}
> We could:
> - create immediately the final object instead of an intermediate array
> - split per location immediately
> - instead of sending when the list as a whole is full, send it when there is 
> enough data for a single location
> It would be:
> {noformat}
> for Operation o: List<Op>{
>   get location
>   add o to todo location.todolist
>   if (location.todolist > maxLocationSize)
>     send location.todolist to region server 
>     clear location.todolist
>     // don't wait, continue the loop
> }
> send remaining
> wait
> {noformat}
> It's not trivial to write if you add error management: retried list must be 
> shared with the operations added in the todolist. But it's doable.
> It's interesting mainly for 'big' writes

--
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