Are there any error messages in the log files on those nodes? - Aaron On Tue, Apr 14, 2009 at 9:03 AM, Mithila Nagendra <mnage...@asu.edu> wrote:
> I ve drawn a blank here! Can't figure out what s wrong with the ports. I > can > ssh between the nodes but cant access the DFS from the slaves - says "Bad > connection to DFS". Master seems to be fine. > Mithila > > On Tue, Apr 14, 2009 at 4:28 AM, Mithila Nagendra <mnage...@asu.edu> > wrote: > > > Yes I can.. > > > > > > On Mon, Apr 13, 2009 at 5:12 PM, Jim Twensky <jim.twen...@gmail.com > >wrote: > > > >> Can you ssh between the nodes? > >> > >> -jim > >> > >> On Mon, Apr 13, 2009 at 6:49 PM, Mithila Nagendra <mnage...@asu.edu> > >> wrote: > >> > >> > Thanks Aaron. > >> > Jim: The three clusters I setup had ubuntu running on them and the dfs > >> was > >> > accessed at port 54310. The new cluster which I ve setup has Red Hat > >> Linux > >> > release 7.2 (Enigma)running on it. Now when I try to access the dfs > from > >> > one > >> > of the slaves i get the following response: dfs cannot be accessed. > When > >> I > >> > access the DFS throught the master there s no problem. So I feel there > a > >> > problem with the port. Any ideas? I did check the list of slaves, it > >> looks > >> > fine to me. > >> > > >> > Mithila > >> > > >> > > >> > > >> > > >> > On Mon, Apr 13, 2009 at 2:58 PM, Jim Twensky <jim.twen...@gmail.com> > >> > wrote: > >> > > >> > > Mithila, > >> > > > >> > > You said all the slaves were being utilized in the 3 node cluster. > >> Which > >> > > application did you run to test that and what was your input size? > If > >> you > >> > > tried the word count application on a 516 MB input file on both > >> cluster > >> > > setups, than some of your nodes in the 15 node cluster may not be > >> running > >> > > at > >> > > all. Generally, one map job is assigned to each input split and if > you > >> > are > >> > > running your cluster with the defaults, the splits are 64 MB each. I > >> got > >> > > confused when you said the Namenode seemed to do all the work. Can > you > >> > > check > >> > > conf/slaves and make sure you put the names of all task trackers > >> there? I > >> > > also suggest comparing both clusters with a larger input size, say > at > >> > least > >> > > 5 GB, to really see a difference. > >> > > > >> > > Jim > >> > > > >> > > On Mon, Apr 13, 2009 at 4:17 PM, Aaron Kimball <aa...@cloudera.com> > >> > wrote: > >> > > > >> > > > in hadoop-*-examples.jar, use "randomwriter" to generate the data > >> and > >> > > > "sort" > >> > > > to sort it. > >> > > > - Aaron > >> > > > > >> > > > On Sun, Apr 12, 2009 at 9:33 PM, Pankil Doshi < > forpan...@gmail.com> > >> > > wrote: > >> > > > > >> > > > > Your data is too small I guess for 15 clusters ..So it might be > >> > > overhead > >> > > > > time of these clusters making your total MR jobs more time > >> consuming. > >> > > > > I guess you will have to try with larger set of data.. > >> > > > > > >> > > > > Pankil > >> > > > > On Sun, Apr 12, 2009 at 6:54 PM, Mithila Nagendra < > >> mnage...@asu.edu> > >> > > > > wrote: > >> > > > > > >> > > > > > Aaron > >> > > > > > > >> > > > > > That could be the issue, my data is just 516MB - wouldn't this > >> see > >> > a > >> > > > bit > >> > > > > of > >> > > > > > speed up? > >> > > > > > Could you guide me to the example? I ll run my cluster on it > and > >> > see > >> > > > what > >> > > > > I > >> > > > > > get. Also for my program I had a java timer running to record > >> the > >> > > time > >> > > > > > taken > >> > > > > > to complete execution. Does Hadoop have an inbuilt timer? > >> > > > > > > >> > > > > > Mithila > >> > > > > > > >> > > > > > On Mon, Apr 13, 2009 at 1:13 AM, Aaron Kimball < > >> aa...@cloudera.com > >> > > > >> > > > > wrote: > >> > > > > > > >> > > > > > > Virtually none of the examples that ship with Hadoop are > >> designed > >> > > to > >> > > > > > > showcase its speed. Hadoop's speedup comes from its ability > to > >> > > > process > >> > > > > > very > >> > > > > > > large volumes of data (starting around, say, tens of GB per > >> job, > >> > > and > >> > > > > > going > >> > > > > > > up in orders of magnitude from there). So if you are timing > >> the > >> > pi > >> > > > > > > calculator (or something like that), its results won't > >> > necessarily > >> > > be > >> > > > > > very > >> > > > > > > consistent. If a job doesn't have enough fragments of data > to > >> > > > allocate > >> > > > > > one > >> > > > > > > per each node, some of the nodes will also just go unused. > >> > > > > > > > >> > > > > > > The best example for you to run is to use randomwriter to > fill > >> up > >> > > > your > >> > > > > > > cluster with several GB of random data and then run the sort > >> > > program. > >> > > > > If > >> > > > > > > that doesn't scale up performance from 3 nodes to 15, then > >> you've > >> > > > > > > definitely > >> > > > > > > got something strange going on. > >> > > > > > > > >> > > > > > > - Aaron > >> > > > > > > > >> > > > > > > > >> > > > > > > On Sun, Apr 12, 2009 at 8:39 AM, Mithila Nagendra < > >> > > mnage...@asu.edu> > >> > > > > > > wrote: > >> > > > > > > > >> > > > > > > > Hey all > >> > > > > > > > I recently setup a three node hadoop cluster and ran an > >> > examples > >> > > on > >> > > > > it. > >> > > > > > > It > >> > > > > > > > was pretty fast, and all the three nodes were being used > (I > >> > > checked > >> > > > > the > >> > > > > > > log > >> > > > > > > > files to make sure that the slaves are utilized). > >> > > > > > > > > >> > > > > > > > Now I ve setup another cluster consisting of 15 nodes. I > ran > >> > the > >> > > > same > >> > > > > > > > example, but instead of speeding up, the map-reduce task > >> seems > >> > to > >> > > > > take > >> > > > > > > > forever! The slaves are not being used for some reason. > This > >> > > second > >> > > > > > > cluster > >> > > > > > > > has a lower, per node processing power, but should that > make > >> > any > >> > > > > > > > difference? > >> > > > > > > > How can I ensure that the data is being mapped to all the > >> > nodes? > >> > > > > > > Presently, > >> > > > > > > > the only node that seems to be doing all the work is the > >> Master > >> > > > node. > >> > > > > > > > > >> > > > > > > > Does 15 nodes in a cluster increase the network cost? What > >> can > >> > I > >> > > do > >> > > > > to > >> > > > > > > > setup > >> > > > > > > > the cluster to function more efficiently? > >> > > > > > > > > >> > > > > > > > Thanks! > >> > > > > > > > Mithila Nagendra > >> > > > > > > > Arizona State University > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > >> > > >> > > > > >
