Hi, Hadoop core comes with HDFS, map-reduce and Yarn.
When you start the core you tend to start hdfs, yarn resource manager on the resource manager node and yarn nodemanager on all slaves. You can also start history server as an option start-dfs.sh ## Start YARN daemons ## Start the resourcemanager daemon ## ONLY ON THE RESOURCEMANAGER NODE! # yarn-daemon.sh start resourcemanager # ## Start the nodemanager daemon # ON ALL SLAVES # yarn-daemon.sh start nodemanager # mr-jobhistory-daemon.sh start historyserver Now yarn is the chosen resource manager. In etc directory $HADOOP_HOME/etc/Hadoop in file slaves you tell hdfs where to start all the datanodes. For example I have a two-node cluster hdfs cat slaves rhes564 rhes5 Now if you just start hdfs it will still go and look at the slaves file to see the datanodes, regardless of yarn it will start the namenode and datanodes! hduser@rhes564:: :/home/hduser/dba/bin> start-dfs.sh 16/06/01 12:08:23 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable Starting namenodes on [rhes564] *rhes564: starting namenode, logging to /home/hduser/hadoop-2.6.0/logs/hadoop-hduser-namenode-rhes564.outrhes564: starting datanode, logging to /home/hduser/hadoop-2.6.0/logs/hadoop-hduser-datanode-rhes564.outrhes5: starting datanode, logging to /home/hduser/hadoop-2.6.0/logs/hadoop-hduser-datanode-rhes5.out* So you still have it. In general you should deploy a resource manager. I do not use map-reduce I use Spark as an execution engine and it does run on yarn-client mode in my case. HTH Dr Mich Talebzadeh LinkedIn * https://www.linkedin.com/profile/view?id=AAEAAAAWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw <https://www.linkedin.com/profile/view?id=AAEAAAAWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw>* http://talebzadehmich.wordpress.com On 1 June 2016 at 03:09, Joseph <wxy81...@sina.com> wrote: > > Hi all, > > I use hadoop 2.7.2, and I just start HDFS, then I can submit mapreduce > jobs and run HIVE 1.2.1. Do the jobs just execute locally If I don't > start YARN? > > ------------------------------ > Joseph >
