Created on 01-20-2016 06:01 PM - edited 09-16-2022 02:58 AM
I'm trying to work with AWS for HDPCD practice exam. I ran " hdfs dfs -ls / " cmd on the terminal and getting " connection refused error". I could see all the services are not running and displays with red colour rectangle icon. I ran the below command
service ambari-agent restart
but, no services are running except Zookeeper and Ganglia services. Please let me know to solve this issue. Thanks! @rich
Created 01-20-2016 08:54 PM
If you startup one of our practice exams and the cluster services are not running, here are some things to try first:
1. Run the start_all_services.sh script. You can watch the progress of this script in Ambari - it uses the Ambari REST API to start all HDP services.
2. Login to Ambari and try to start services that way
3. Restart the ambari-agent process on each node in the cluster (password for root is hadoop), then run start_all_services.sh again:
ssh root@namenode "ambari-agent restart" ssh root@resourcemanager "ambari-agent restart" # This only applies the HDPCA exam ssh root@hiveserver "ambari-agent restart" # This only applies to the HDPCA exam
If none of the steps above fix the issue, then it is likely an issue with the Docker containers not starting properly. Since you do not have root access on your practice exam, the quickest solution is to simply terminate your EC2 instance and startup another one.
Created 04-16-2016 04:23 PM
I am using us-west-2c. Will this be a issue?
Created 04-17-2016 11:10 AM
I don't know, but try a different a region and see if you have any success.
Created 04-26-2016 06:48 PM
my region is N virginia and public ip is ec2-54-210-61-32.compute-1.amazonaws.com
Created 04-26-2016 06:52 PM
Did you try this:
ssh root@namenode "ambari-agent restart"
Created 04-26-2016 07:00 PM
yes I executed the command
The log files indicate same error on host
Created 04-26-2016 07:03 PM
1. Run /home/horton/start_all_services.sh
2. Wait 5 minutes
3. If Hadoop services are not started after 5 minutes, terminate your EC2 instance and create a new one because something failed in your VM
Created 04-26-2016 07:49 PM
it works now.. thanks for all your help
Created 04-27-2016 02:43 AM
It worked for me by restarting the ambari service. But as Rich suggested we need to wait for 5 mins to get all service restarted. Thanks Rich.
Created 08-29-2017 08:04 PM
Hello, can someone tell me how to scp to the practice EC2, copy my notes to my local before I terminate the instance.
I use the Public DNS:22, and chose the key file, but it still prompts me the user name and password, i tried U: horton and P: hadoop, cannot pass the authentication.
Created 08-10-2018 12:23 AM
I wanted to take HDPCD exam . .tried logging in AWS. but when i do hadoop fs -ls .. it throws connection refused. few times. Tried recreating the instance .. still the same error.. tried starting all the services individually in ambari ... still the same error. The above root@hostname isn't working. Can you pl help ASAP? i am planning to take the exam this week