Am curious how folks are sizing memory for Task nodes. It didn't seem to me that either map (memory needed ~ chunk size) or reduce (memory needed ~ io.sort.mb - yahoo's benchmark sort run sets it to low hundreds) tasks consumed a lot of memory in the normal course of affairs.
(there could be exceptions I guess if the reduce group size is extremely large - but that seems like an outlier). So curious on why we might want to configure more than 1-1.5GB per core for task nodes. -----Original Message----- From: Allen Wittenauer [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 25, 2007 10:02 AM To: hadoop-user@lucene.apache.org Subject: Re: hardware specs for hadoop nodes On 9/25/07 9:27 AM, "Bob Futrelle" <[EMAIL PROTECTED]> wrote:> > I'm in the market to buy a few machines to set up a small cluster and am > wondering what I should consider. If it helps, we're using quad core x86s with anywhere from 4g to 16g of ram. We've got 4x500g sata drives per box, no raid, swap and root taking a chunk out of each drive and the rest used for HDFS and/or MR work. While you can certainly go a much more heterogeneous route than we have, it should be noted that the more differences in the hardware/software layout, the more difficult is going to be to maintain them. This is especially true for large grids where hand-tuning individual machines just isn't worth the return on effort. > Or should I just spread Hadoop over some friendly machines already in my > College, buying nothing? Given the current lack of a security model in Hadoop and the direction that a smattering of Jira's are heading, "friendly" could go either way: either not friendly enough or too friendly. :)
