The reason being that when you write something in HDFS, it guarantees that it will be written to the specified number of replicas. So if your replication factor is 2 and one of your node (out of 2) is down, then it cannot guarantee the 'write'.
The way to handle this to have a cluster of more than 2 nodes. Basically large enough so that the chance of nodes going down is low. More here: http://www.bigdataplanet.info/2013/10/Hadoop-Tutorial-Part-4-Write-Operations-in-HDFS.html Regards, Shahab On Mon, Jul 28, 2014 at 12:44 PM, Satyam Singh <satyam.si...@ericsson.com> wrote: > @vikas i have initially set 2 but after that i have make one DN down. So > you are saying from initial i have to make replication factor as 1 even i > have DN 2 active initially. If so then what is the reason? > > On 07/28/2014 10:02 PM, Vikas Srivastava wrote: > >> What replication have you set for cluster. >> >> Its should be 1 in your case. >> >> On Jul 28, 2014 9:26 PM, Satyam Singh <satyam.si...@ericsson.com> wrote: >> >>> Hello, >>> >>> >>> I have hadoop cluster setup of one namenode and two datanodes. >>> And i continuously write/read/delete through hdfs on namenode through >>> hadoop client. >>> >>> Then i kill one of the datanode, still one is working but writing on >>> datanode is getting failed for all write requests. >>> >>> I want to overcome this scenario because at live traffic scenario any of >>> datanode might get down then how do we handle those cases. >>> >>> Can anybody face this issue or i am doing something wrong in my setup. >>> >>> Thanx in advance. >>> >>> >>> Warm Regards, >>> Satyam >>> >> >
