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 <[email protected]> wrote: > Yes I can.. > > > On Mon, Apr 13, 2009 at 5:12 PM, Jim Twensky <[email protected]>wrote: > >> Can you ssh between the nodes? >> >> -jim >> >> On Mon, Apr 13, 2009 at 6:49 PM, Mithila Nagendra <[email protected]> >> 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 <[email protected]> >> > 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 <[email protected]> >> > 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 <[email protected]> >> > > 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 < >> [email protected]> >> > > > > 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 < >> [email protected] >> > > >> > > > > 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 < >> > > [email protected]> >> > > > > > > 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 >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > >> > > >> > >> > >
