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Posted to hdfs-dev@hadoop.apache.org by Thanh Do <th...@cs.wisc.edu> on 2010/11/14 18:31:19 UTC
transferToAllowed
Hi all,
Can somebody let me know what is this
parameter used for:
dfs.datanode.transferTo.allowed
It is not in default config,
and the maxChunksPerPacket depends on it.
Thanks so much.
Thanh
Re: transferToAllowed
Posted by Raghu Angadi <ra...@apache.org>.
When it is set to true (default), DN uses JDK's transferTo() interface to
avoid extra buffer copies.
It is possible though rare, some specific platform may not support this
efficiently or is unstable. The config exists to let users disable this
optimization. We have not seen any users that have disabled this though...
Raghu.
On Sun, Nov 14, 2010 at 9:56 AM, Thanh Do <th...@cs.wisc.edu> wrote:
> got it here
> https://issues.apache.org/jira/browse/HADOOP-3164
>
>
> On Sun, Nov 14, 2010 at 11:31 AM, Thanh Do <th...@cs.wisc.edu> wrote:
>
>> Hi all,
>>
>> Can somebody let me know what is this
>> parameter used for:
>>
>> dfs.datanode.transferTo.allowed
>>
>> It is not in default config,
>> and the maxChunksPerPacket depends on it.
>>
>> Thanks so much.
>> Thanh
>>
>
>
Re: transferToAllowed
Posted by Raghu Angadi <ra...@apache.org>.
When it is set to true (default), DN uses JDK's transferTo() interface to
avoid extra buffer copies.
It is possible though rare, some specific platform may not support this
efficiently or is unstable. The config exists to let users disable this
optimization. We have not seen any users that have disabled this though...
Raghu.
On Sun, Nov 14, 2010 at 9:56 AM, Thanh Do <th...@cs.wisc.edu> wrote:
> got it here
> https://issues.apache.org/jira/browse/HADOOP-3164
>
>
> On Sun, Nov 14, 2010 at 11:31 AM, Thanh Do <th...@cs.wisc.edu> wrote:
>
>> Hi all,
>>
>> Can somebody let me know what is this
>> parameter used for:
>>
>> dfs.datanode.transferTo.allowed
>>
>> It is not in default config,
>> and the maxChunksPerPacket depends on it.
>>
>> Thanks so much.
>> Thanh
>>
>
>
Re: transferToAllowed
Posted by Thanh Do <th...@cs.wisc.edu>.
got it here
https://issues.apache.org/jira/browse/HADOOP-3164
On Sun, Nov 14, 2010 at 11:31 AM, Thanh Do <th...@cs.wisc.edu> wrote:
> Hi all,
>
> Can somebody let me know what is this
> parameter used for:
>
> dfs.datanode.transferTo.allowed
>
> It is not in default config,
> and the maxChunksPerPacket depends on it.
>
> Thanks so much.
> Thanh
>
Re: transferToAllowed
Posted by Thanh Do <th...@cs.wisc.edu>.
got it here
https://issues.apache.org/jira/browse/HADOOP-3164
On Sun, Nov 14, 2010 at 11:31 AM, Thanh Do <th...@cs.wisc.edu> wrote:
> Hi all,
>
> Can somebody let me know what is this
> parameter used for:
>
> dfs.datanode.transferTo.allowed
>
> It is not in default config,
> and the maxChunksPerPacket depends on it.
>
> Thanks so much.
> Thanh
>