Namespace divides are designed with application-level separation in mind. Sharing a file across namespaces does not make a whole lot of sense to me.
Anyhow, the data is on the same set of DNs, and there's HA for NN's own availability (if thats really a concern), so I don't see why anyone would like to _maintain_ two synced copies of files as thats just data duplication when all you need is a simple path (viewfs)/URI (hdfs) to access a file lying on a different NN. The reason you mention of metadata availability doesn't sound logical - in such a case a person has to build a self failover of URIs for said file, which they can simply avoid by using HDFS HA for the hosting NN. On Wed, May 15, 2013 at 7:47 PM, Michael Segel <[email protected]> wrote: > Quick question... > So when we have a cluster which has multiple namespaces (multiple name nodes) > , why would you have a file in two different namespaces? > > -- Harsh J
