Federation is just a namenode namespace management capability. It is designed to control namenode management and to provide scalability for namenode. I don't think it poses any security or restrictions on accesssing the HDFS filesystem. I guess this link would help for your question 2 - http://hadoop.apache.org/docs/r2.4.0/hadoop-project-dist/hadoop-hdfs/ViewFs.html
On Tue, Jul 15, 2014 at 10:06 AM, Shani Ranasinghe <shanir...@gmail.com> wrote: > Hi, > > Thanks for the information. > > Can I have an answer for the question 2 please? Appreciate any help. > > > On Wed, Feb 5, 2014 at 1:41 PM, praveenesh kumar <praveen...@gmail.com> > wrote: > >> Hi Shani, >> >> I haven't done any implementation on HDFS federation, but as far as I >> know, 1 namenode can handle only 1 namespace at this time. I hope that >> helps. >> >> Regards >> Prav >> >> >> On Wed, Feb 5, 2014 at 8:05 AM, Shani Ranasinghe <shanir...@gmail.com> >> wrote: >> >>> Hi, >>> >>> Any help on this please? >>> >>> >>> >>> On Mon, Feb 3, 2014 at 12:14 PM, Shani Ranasinghe <shanir...@gmail.com> >>> wrote: >>> >>>> >>>> Hi, >>>> I would like to know the following. >>>> >>>> 1) Can there be multiple namespaces in a single namenode? is it >>>> recommended? (I'm having a multi-tenant environment in mind) >>>> >>>> 2) Let's say I have a federated namespace/namenodes. There are two >>>> namenodes A /namespace A1 and namenode B/namespace B1, and have 3 >>>> datanodes. Can someone from namespace A1, access the datanode's data in >>>> anyway (hacking) belonging to namespace B1. If not how is it handled? >>>> >>>> After going through a lot of reference, my understanding on HDFS >>>> multi-tenancy and federation is that for multi-tenancy what we could do is >>>> use file/folder permissions (u,g,o) and ACL's. Or we could dedicate a >>>> namespace per tenant. The issue here is that a namenode (active namenode, >>>> passive namenode and secondary namenode) has to be assigned per tenant. Is >>>> there any other way that multi tenancy can be achieved? >>>> >>>> On federation, let's say I have a namenode for /marketing and another >>>> for /finance. Lets say that marketing bears the most load. How can we load >>>> balance this? is it possible? >>>> >>>> Appreciate any help on this. >>>> >>>> Regards, >>>> Shani. >>>> >>>> >>>> >>>> >>> >> >
