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 <[email protected]>: > 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 <[email protected]> > 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
