[ 
https://issues.apache.org/jira/browse/HDFS-10326?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15256848#comment-15256848
 ] 

Colin Patrick McCabe commented on HDFS-10326:
---------------------------------------------

bq. I think we can keep the configurability, but set the default to 0.

I agree.  The reason why the original patches didn't set the default was 
basically that we wanted to be conservative.  Basically, we were adding the 
option to use auto-tuning, but not making it the default.  If we strongly 
believe that auto-tuning should be the default, we should make these options 
default to 0 unless set by the admin.

> Disable setting tcp socket send/receive buffers for write pipelines
> -------------------------------------------------------------------
>
>                 Key: HDFS-10326
>                 URL: https://issues.apache.org/jira/browse/HDFS-10326
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: datanode, hdfs
>    Affects Versions: 2.6.0
>            Reporter: Daryn Sharp
>            Assignee: Daryn Sharp
>
> The DataStreamer and the Datanode use a hardcoded 
> DEFAULT_DATA_SOCKET_SIZE=128K for the send and receive buffers of a write 
> pipeline.  Explicitly setting tcp buffer sizes disables tcp stack 
> auto-tuning.  
> The hardcoded value will saturate a 1Gb with 1ms RTT.  105Mbs at 10ms.  
> Paltry 11Mbs over a 100ms long haul.  10Gb networks are underutilized.
> There should either be a configuration to completely disable setting the 
> buffers, or the the setReceiveBuffer and setSendBuffer should be removed 
> entirely.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to