Hi Rohan, How are you measuring throughput? The throughput from a single client will not scale up as the cluster size increases, as it does not parallelize reads across multiple nodes. Of course it will also be limited by the inbound bandwidth of that node.
-Todd On Fri, May 14, 2010 at 1:23 AM, Rohan Rai <rohan....@inmobi.com> wrote: > Hi > > Is there a relationship between HDFS Read throught put and Disk Read > throughput. > > If yes what would be that. > > Lets say we have a disk giving us 120 MB/s > > And a Cluster of 6 Nodes > > Each Node having 6 disk. > > So in an absolutely ideal world it should give us a through put > of 120*6*6 MB/s if used in parallel > In a non ideal world we can divide above by a factor of x > > Then why is that the general CLUSTER read throughput is so very less. > > Generally it hovers around 90MB/s. > > How is the throughput which cluster provides is accounted for. > > Just for information, configs are , 8 GB RAM, 250 GB HDD, 8 Maps per > node, 128 Kb Block size > > > Regards > Rohan > > > > > The information contained in this communication is intended solely for the > use of the individual or entity to whom it is addressed and others > authorized to receive it. It may contain confidential or legally privileged > information. If you are not the intended recipient you are hereby notified > that any disclosure, copying, distribution or taking any action in reliance > on the contents of this information is strictly prohibited and may be > unlawful. If you have received this communication in error, please notify us > immediately by responding to this email and then delete it from your system. > The firm is neither liable for the proper and complete transmission of the > information contained in this communication nor for any delay in its > receipt. > -- Todd Lipcon Software Engineer, Cloudera
