Hi Dbruba, Thanx for your reply.
On the first part (NameNode HA and failover), our experience with NFS has not been very good. Is having a Db as a backing store for NameNode an option (I understand that this may not be part of the current release 0.15.0 and would be a new feature)? -Taj Dhruba Borthakur wrote: > > 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. > > > -- View this message in context: http://www.nabble.com/NameNode-HA-tf4846281.html#a13878663 Sent from the Hadoop Users mailing list archive at Nabble.com.
