Hi Dmitriy,
Thanks for explaining. I understand.
In situations using Name node, it's better to use DUAL_SYNC mode.
May I ask one more?
> Basically it means that every time a data is changed in Ignite, it will also
> be changed in the underlying HDFS, either synchronously or asynchronously,
> based on the IGFS configuration.
When using PRIMARY mode, I think that name node is not referenced.
What kind of use case is assumed for PRIMARY mode?
thanks.
2017-04-04 15:11 GMT+09:00 Dmitriy Setrakyan :
> Hi Massayuki,
>
> Ignite itself does not have a concept of a NameNode. It goes directly to the
> cluster node responsible for storing the data based on a key's hashcode.
>
> The only time when a NameNode would come into a play, is when Hadoop HDFS is
> configured as an underlying write-through file system. Basically it means
> that every time a data is changed in Ignite, it will also be changed in the
> underlying HDFS, either synchronously or asynchronously, based on the IGFS
> configuration. In this case, HDFS would contact the NameNode whenever the
> data is written into it, based on the its own native protocol, which has
> nothing to do with Ignite itself.
>
> Let me know if you have more questions.
>
> D.
>
> On Sun, Apr 2, 2017 at 5:47 AM, Masayuki Takahashi
> wrote:
>>
>> Hi,
>>
>> I am trying to use IGFS on HDFS.
>>
>> If I set DUAL_ASYNC to IGFS mode and execute 'hdfs dfs -put ...', when
>> does the file info write to HDFS NameNode?
>>
>> Also, if I set PRIMARY to IGFS mode and put a new file, does the file
>> info write to HDFS NameNode?
>>
>> thanks.
>> --
>> Masayuki Takahashi
>
>
--
高橋 真之