Support Questions

amcbarnett · ‎08-25-2016

I am not able to install the HAWQ Standby master on an AWS cluster running HDP 2.4.2 and Ambari 2.2.2 Here is the error: "This can be run only on master or standby host"

Not sure what that means. It is not being installed on a DN, with PFX installed. It is not bing installed on the Ambari node. I am using the Name Node (since I only have 3 HDP master nodes) to install the HAWQ Standby Master. I attempted to remove the HAWQ Standby (that does not start) from the Name node and placed it on another node just to test. It gives the same error. So right now I am just running without a standby master. See

How do I begin trouble shooting this?

amcbarnett · ‎08-25-2016

@Vineet @Pratheesh Nair Ok.. Here is solution

So apparently if you are installing on Amazon AWS EC2 (remember you are only given access to ec2-user, not root), and if you decided to NOT do passwordless ssh with default key named id_rsa for that ec2-user when installing Ambari and its agents, when you try to install Hortonworks HDB (HAWQ) via Ambari, Ambari WILL NOT exchange the keys for the gpadmin user for you. It would create the gpadmin user with the password you give it on the HAWQ config screen during install, but no keys exchanged.

NOTE: for my nodes I had a key for ssh that was NOT default name of id_rsa. I do not know if this is a combination of using a non root user or the fact that ec2-user did not have its own passwordless ssh with default key named id_rsa. In anycase ONLY on the HAWQ Master, for gpadmin would the keys exist. If you tried the following to generate keys on the HAWQ Master you would still get an error, where it would NOT even accept the default gpadmin user password you set, even though it works. That was surprising.

su gpadmin

> source /usr/local/hawq/greenplum_path.sh
> hawq ssh-exkeys -f Hosts

>Enter password for existing user for node <......>
>Enter password for existing user for node <......>
>Enter password for existing user for node <......>

So in essence you have to manually go to each node, and copy authorized_keys file from HAWQ Master to each node (chmod 600), into the /home/gpadmin/.ssh/ so that you can at least password ssh from that HAWQ master node. Then you run the ssh-exkeys manually and it would work.

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vgoel · ‎09-02-2016

I'll just add two more bits that I have seen some people run into often. Hopefully this is helpful in similar scenarios.

1) /etc/ssh/sshd_config file: PasswordAuthentication should be set to yes

2) In AWS, /etc/cloud/cloud.cfg should have ssh_pwauth set to True (or 1, I think). Otherwise, cloud init keeps disabling PasswordAuthentication options in ssh config.

p_routray · ‎11-12-2016

For me this solved the problem. I was initially doing the cloud.cfg change on all the HAWQ hosts but ignoring one of the master nodes as it was not supposed to have HAWQ components. However, I had configured for using the YARN scheduler for which that node was master.

This dependency was creating the above mentioned problem.

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Error Installing HDB HAWQ Standby Master