Steps to Setup dcli on All Nodes in a Oracle Big Data Appliance Cluster

Asset ID:	1-79-1535416.1
Update Date:	2018-05-07
Keywords:

Solution Type Predictive Self-Healing Sure

Solution 1535416.1 : Steps to Setup dcli on All Nodes in a Oracle Big Data Appliance Cluster

Applies to:

Big Data Appliance X3-2 Hardware - Version All Versions and later
Linux x86-64
Validated for Currency on Sep 29th 2014

Purpose

This document will provide steps on how to setup dcli on all nodes in a Oracle Big Data Appliance(BDA) Cluster.

Scope

This document is intended for System administrators of the Oracle Big Data Appliance.

Details

DCLI is a distributed command line interface utility. The dcli utility allows you to execute commands across a group of servers on Oracle Big Data Appliance and returns the output. The dcli utility allows you to run commands across multiple Oracle Big Data Appliance servers in parallel using the Infiniband(bondib0) interface to make the connections. The dcli utility may be run from any server. Currently a restriction on BDA is dcli can only be setup and executed as root.

For dcli options refer to Doc ID 1476008.1 Using DCLI on Oracle Big Data Appliance.

1) The dcli utility requires a password-less Secure Shell (SSH) between the local server and all target servers. The dcli utility is run on the local server, and the commands specified in dcli execute on the target servers.

Two scripts facilitate the use of SSH on Oracle Big Data Appliance: setup-root-ssh and remove-root-ssh. These scripts accept two options that are also used by dcli:

-C : Targets all the servers in a Hadoop cluster

-g/-c : Targets a user-defined set of servers

NOTE: By default if -C or -g(list of nodes in a file) /-c (comma-separated list of nodes) options are not specified, the command will run on all servers in the rack as specified in /opt/oracle/bda/rack-hosts-infiniband

a) In a single rack environment , execute below command as root on node01 to setup password-less Secure Shell (SSH) between node01 and all the nodes in the same rack as specified in /opt/oracle/bda/rack-hosts-infiniband.

# setup-root-ssh

Enter root password:
spawn /opt/oracle/bda/bin/dcli -c ...,192.***.**.7,192.***.**.8,192.***.**.9,... -k
....
root@192.***.**.7's password:
root@192.***.**.8's password:
root@192.***.**.9's password:
...
192.***.**.7: ssh key added
192.***.**.8: ssh key added
192.***.**.9: ssh key added
...
setup-root-ssh succeeded

b) In a multi rack environment , execute below command as root on node01 of primary rack to setup password-less Secure Shell (SSH) between node01 and all the nodes in the cluster as specified in /opt/oracle/bda/cluster-hosts-infiniband.

# setup-root-ssh -C

2) To check if dcli is correctly setup on node01 execute below command. If everything is setup correctly the output will list all nodes in the primary rack.

# dcli hostname

............
192.***.**.7: scaj*****7.us.oracle.com
192.***.**.8: scaj*****8.us.oracle.com
192.***.**.9: scaj*****9.us.oracle.com
........

In a multirack cluster use -C option to verify dcli is setup correctly. For example 'dcli -C hostname', will list all the nodes in the cluster if everything is correct.

3) In order to propagate dcli setup from node01 to all other nodes in the cluster, execute below commands to copy the ssh setup files across all nodes in the cluster.

-f FILE File to be copied
-d DESTFILE Destination directory or file

dcli -C -f /root/.ssh/id_rsa        -d /root/.ssh/
dcli -C -f /root/.ssh/id_rsa.pub    -d /root/.ssh/
dcli -C -f /root/.ssh/known_hosts   -d /root/.ssh/

In a multi-rack cluster use -C option .

4) Now one should be able to execute dcli commands as root from any node in the BDA cluster.

References

<NOTE:1476008.1> - Using DCLI on Oracle Big Data Appliance

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