@Harshal Joshi For the Host-config-is-in-invalid-state. Please have a look at this post great API's for changing the state of a service component Link ... View more

@Prakash Punj Definitely all the steps I attached MUST be implemented but if the Ambari server had already locked that port for use then subsequent attempts would't work untill the process using that Ambari port is killed . Happy it worked out for you. ... View more

@Ram D To kill an Application you can also use the Application State by using a PUT operation to set the application state to KILLED. For example: curl -v -X PUT -d '{"state": "KILLED"}''http://localhost:8088/ws/v1/cluster/apps/application_1409421698529_0012' Hope that helps ... View more

@Michael Rife Run a checksum against the file you might have a corrupt file. ... View more

@Harshal Joshi An Ambari managed cluster should be stopped gracefully just like an oracle database you . A reboot is the equivalent of shutdown abort in Oracle.When you reboot your cluster its advisable to start the components manually in the order Ambari server,HDFS,YARN Otherwise have a look at this link ... View more

@Prakash Punj Sorry what you ave done on the new host is not enough . There are are more important steps that you should never ignore, Assuming that the your corporate or whatever network rules allows the new host and the Ambari server to communicate no proxy or firewall rules etc. Assuming you are on linux both hosts should have FQDN entries in the /etc/host Configure passwordless connection for the user installing hetween the 2 host etc Just have a look at attached document and again IGNORE nothing all have to be successful implemented to succeed your new host integration to your cluster PS.remember to clean the failed registration too ... View more

@Prakash Punj What's the purpose of Region Server? Read this Where is should be located ? Every datanode ? You run RegionServers on the same servers as DataNodes. What's the purpose of HBase Master? HBase provides low-latency random reads and writes on top of HDFS and it’s able to handle petabytes of data. One of the interesting capabilities in HBase is Auto-Sharding, which simply means that tables are dynamically distributed by the system when they become too large. The HBase Architecture has two main services: HMaster that is responsible for coordinating Regions in the cluster and execute administrative operations; HRegionServer responsible to handle a subset of the table’s data. HBase is NoSql database. What does it store ? HBase is a distributed, nonrelational (columnar) database that utilizes HDFS as its persistence store for data. Hope that answers you .. ... View more

@Vincent McGarry Solution 1 1. Please check that the daemons have write privileges to the log directory Stop and start namenode and datanode daemons in debug mode, following command can be used. Solution 2 You need to do something like this: bin/stop-all.sh (or stop-dfs.sh and stop-yarn.sh in the 2.x serie) rm -Rf /app/tmp/hadoop-your-username/* bin/hadoop namenode -format (or hdfs in the 2.x serie) Solution 3 /usr/local/hadoop/sbin/hadoop-daemon.sh stop namenode ; hadoop namenode On datanode host, Execute the following command /usr/local/hadoop/sbin/hadoop-daemon.sh stop datanode ; hadoop datanode Check the logs messages from both daemons. ... View more