Here is some info on recovering from a failed Namenode: http://wiki.apache.org/lucene-hadoop/NameNodeFailover
The fact that there is a single Namenode does mean that it could possibly become the bottleneck when many thousands of clients/Datanodes run on the cluster simultaneously. However, the design is such that it is scalable to a huge number of clients/Datanodes. Also, work is going on continuously to improve scalabilty. Thanks, Dhruba -----Original Message----- From: j2eeiscool [mailto:[EMAIL PROTECTED] Sent: Tuesday, November 20, 2007 12:47 PM To: [email protected] Subject: NameNode HA Hi, Based on the documentation I have read, there is one instance of a NameNode. Are there recommended approaches on making the NameNode HA: 1.Have a backup which takes over. Data between primary and backup is shared thru shared files , DB etc. Also does having a single NameNode limit the no. of concurrent HDFS clients ? I understand that HDFS Readers and Writers use the DataNode(s) eventually, but the initial access point is the NameNode. I would really appreciate help on these (I am evaluating HDFS for use as a Concurrent, Reliable, Performant Distributed File System). Thanx, Taj -- View this message in context: http://www.nabble.com/NameNode-HA-tf4846281.html#a13865411 Sent from the Hadoop Users mailing list archive at Nabble.com.
