Ashish Could this be related to the scheduler you are using and its settings?.
On lab environments when running a single type of job I often use FairScheduler (the YARN default in 2.2.0 is CapacityScheduler) and it does a good job distributing the load. You could give that a try (https://hadoop.apache.org/docs/current/hadoop-yarn/hadoop-yarn-site/FairSch eduler.html) I think just changing yarn-site.xml as follows could demonstrate this theory (note that how the jobs are scheduled depend on resources such as memory on the nodes and you would need to setup yarn-site.xml accordingly). <property> <name>yarn.resourcemanager.scheduler.class</name> <value>org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairSche duler</value> </property> Regards ./g From: Ashish Jain [mailto:[email protected]] Sent: Thursday, January 09, 2014 6:46 AM To: [email protected] Subject: Re: Distributing the code to multiple nodes Another point to add here 10.12.11.210 is the host which has everything running including a slave datanode. Data was also distributed this host as well as the jar file. Following are running on 10.12.11.210 7966 DataNode 8480 NodeManager 8353 ResourceManager 8141 SecondaryNameNode 7834 NameNode On Thu, Jan 9, 2014 at 6:12 PM, Ashish Jain <[email protected]> wrote: Logs were updated only when I copied the data. After copying the data there has been no updates on the log files. On Thu, Jan 9, 2014 at 5:08 PM, Chris Mawata <[email protected]> wrote: Do the logs on the three nodes contain anything interesting? Chris On Jan 9, 2014 3:47 AM, "Ashish Jain" <[email protected]> wrote: Here is the block info for the record I distributed. As can be seen only 10.12.11.210 has all the data and this is the node which is serving all the request. Replicas are available with 209 as well as 210 1073741857: 10.12.11.210:50010 View Block Info 10.12.11.209:50010 View Block Info 1073741858: 10.12.11.210:50010 View Block Info 10.12.11.211:50010 View Block Info 1073741859: 10.12.11.210:50010 View Block Info 10.12.11.209:50010 View Block Info 1073741860: 10.12.11.210:50010 View Block Info 10.12.11.211:50010 View Block Info 1073741861: 10.12.11.210:50010 View Block Info 10.12.11.209:50010 View Block Info 1073741862: 10.12.11.210:50010 View Block Info 10.12.11.209:50010 View Block Info 1073741863: 10.12.11.210:50010 View Block Info 10.12.11.209:50010 View Block Info 1073741864: 10.12.11.210:50010 View Block Info 10.12.11.209:50010 View Block Info --Ashish On Thu, Jan 9, 2014 at 2:11 PM, Ashish Jain <[email protected]> wrote: Hello Chris, I have now a cluster with 3 nodes and replication factor being 2. When I distribute a file I could see that there are replica of data available in other nodes. However when I run a map reduce job again only one node is serving all the request :(. Can you or anyone please provide some more inputs. Thanks Ashish On Wed, Jan 8, 2014 at 7:16 PM, Chris Mawata <[email protected]> wrote: 2 nodes and replication factor of 2 results in a replica of each block present on each node. This would allow the possibility that a single node would do the work and yet be data local. It will probably happen if that single node has the needed capacity. More nodes than the replication factor are needed to force distribution of the processing. Chris On Jan 8, 2014 7:35 AM, "Ashish Jain" <[email protected]> wrote: Guys, I am sure that only one node is being used. I just know ran the job again and could see that CPU usage only for one server going high other server CPU usage remains constant and hence it means other node is not being used. Can someone help me to debug this issue? ++Ashish On Wed, Jan 8, 2014 at 5:04 PM, Ashish Jain <[email protected]> wrote: Hello All, I have a 2 node hadoop cluster running with a replication factor of 2. I have a file of size around 1 GB which when copied to HDFS is replicated to both the nodes. Seeing the block info I can see the file has been subdivided into 8 parts which means it has been subdivided into 8 blocks each of size 128 MB. I use this file as input to run the word count program. Some how I feel only one node is doing all the work and the code is not distributed to other node. How can I make sure code is distributed to both the nodes? Also is there a log or GUI which can be used for this? Please note I am using the latest stable release that is 2.2.0. ++Ashish
