The namenode is pretty much driven by the number of blocks and the number of files in your HDFS, and to a lessor extent, the rate of create/open/write/close of files. If you have any instability in your datanodes, there is a great increase in namenode loading.
On Tue, Jul 14, 2009 at 4:16 AM, Hrishikesh Agashe < [email protected]> wrote: > Hi, > > Is there any relationship between how many map and how many reduce tasks I > am running per node and what is capacity (RAM, CPU) of my NameNode? > i.e. if I want to run more maps and more reduce tasks per node then RAM of > NameNode should be high? > Similarly does NameNode capacity should be driven by how many number of > machines are running map reduce tasks? > > Please let me know. > > --Hrishi > > DISCLAIMER > ========== > This e-mail may contain privileged and confidential information which is > the property of Persistent Systems Ltd. It is intended only for the use of > the individual or entity to which it is addressed. If you are not the > intended recipient, you are not authorized to read, retain, copy, print, > distribute or use this message. If you have received this communication in > error, please notify the sender and delete all copies of this message. > Persistent Systems Ltd. does not accept any liability for virus infected > mails. > -- Pro Hadoop, a book to guide you from beginner to hadoop mastery, http://www.amazon.com/dp/1430219424?tag=jewlerymall www.prohadoopbook.com a community for Hadoop Professionals
