Hello, I had a Cloudera Hadoop cluster running on AWS EC2 instances. I used the Cloudera Manager to setup and configure the cluster. It is a CDH 4.4.0 version package.
Everything was running fine till I got a mail from Amazon saying that I need to re-instantiate one of my EC2 instances and create a new one as the old one was to be terminated. Un-luckily it was the the Master Node. So I did the following: 1. Made an image of the running Master Node instance. 2. Stopped the cluster services from the cloudera manager. 3. Terminated the existing the node. 4. Setup a new node with the AMI image of old Master node. 5. Configured the same private IP Address as the old master node, so it also got the same DNS address. 6. Since the new machine was a clone of the old master node. I did not change anything. 7. I restarted all the services from Cloudera Manager. 8. NameNode failed to start saying that DFS was not formatted. 9. I formatted the DFS from the Cloudera Manager form the NameNode service menu. 10. The restarted the HDFS service with the Namenode service, Successfully. 11. Now All the Task Trackers are running. 12. I can access the Master Node with the old SSH keys and the old IP Adress. 13. But the Task Tracker on the name node gives an error while starting up. 14. It gives the following error: *org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.security.AccessControlException): Permission denied: user=mapred, access=WRITE, inode="/":hdfs:supergroup:drwxr-xr-x* Please help me resolve this error. Earlier also I did not have a user named mapred. Everything was running fine with the user hdfs. Thanking You, -- Regards, Ouch Whisper 010101010101
