Yes, if this is an HDFS cluster deployed with HA using the Quorum Journal Manager, then it is protected against data loss. This documentation page describes the configuration and how the architecture achieves it.
http://hadoop.apache.org/docs/r2.6.0/hadoop-project-dist/hadoop-hdfs/HDFSHighAvailabilityWithQJM.html There can be a small risk of an HDFS client reading stale data from an old NameNode that still thinks it's active. To mitigate against this, you can configure fencing methods to stop the old NameNode. For more information on this, see "dfs.ha.fencing.methods" in the same document. Chris Nauroth Hortonworks http://hortonworks.com/ On Tue, Jan 13, 2015 at 2:46 PM, Kondala Palaka < [email protected]> wrote: > Hi friends, > > > > Is there really *zero* data loss in case of a namenode failure in an HA > (active-passive) environment? > > > > Thanks in advance for any pointers.. > > *Kondala Palaka* > > > -- CONFIDENTIALITY NOTICE NOTICE: This message is intended for the use of the individual or entity to which it is addressed and may contain information that is confidential, privileged and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, you are hereby notified that any printing, copying, dissemination, distribution, disclosure or forwarding of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and delete it from your system. Thank You.
