(Optional) Install Cloudera Data Science Workbench on Worker Hosts

Cloudera Data Science Workbench supports adding and removing additional worker hosts at any time. Worker hosts allow you to transparently scale the number of concurrent workloads users can run.

Worker hosts are not required for a fully-functional Cloudera Data Science Workbench deployment. For proof-of-concept deployments, you can deploy a 1-host cluster with just a Master host. The Master host can run user workloads just as a worker host can.

Use the following steps to add worker hosts to Cloudera Data Science Workbench. Note that airgapped clusters and non-airgapped clusters use different files for installation.

note

To download Cloudera Data Science Workbench, you must have an active subscription agreement along with the required authentication credentials (namely, the username and password). The authentication credentials are provided in an email sent to the customer account from Cloudera when a new license is issued.

If you do not have the authentication credentials, contact your account representative to receive the same.

You can download the CDSW version 1.8 or later using one of the following methods:

Log in to the Cloudera Downloads web page and download the required files
Use the URLs listed in this section and provide the login information as provided with your Cloudera subscription.

Non-airgapped Installation - Download the Cloudera Data Science Workbench repo file (cloudera-cdsw.repo) from the following location:
```
https://archive.cloudera.com/p/cdsw1/1.8.0/redhat7/yum/cloudera-cdsw.repo
```
Airgapped installation - For airgapped installations, download the Cloudera Data Science Workbench RPM file from the following location:
```
https://archive.cloudera.com/p/cdsw1/1.8.0/redhat7/yum/RPMS/x86_64/
```
note
Make sure all Cloudera Data Science Workbench hosts (master and worker) are running the same version of Cloudera Data Science Workbench.
Skip this step for airgapped installations. Add the Cloudera Public GPG repository key. This key verifies that you are downloading genuine packages.
```
sudo rpm --import https://archive.cloudera.com/p/cdsw1/1.8.0/redhat7/yum/RPM-GPG-KEY-cloudera
```
Non-airgapped Installation - Install the latest RPM with the following command:
```
sudo yum install cloudera-data-science-workbench
```
Airgapped Installation - Copy the RPM downloaded in the previous step to the appropriate gateway host. Then, use the complete filename to install the package. For example:
```
sudo yum install cloudera-data-science-workbench-1.8.0.12345.rpm
```
For guidance on any warnings displayed during the installation process, see Understanding Installation Warnings.
Copy cdsw.conf file from the master host:
```
scp root@<cdsw-master-hostname.your_domain.com>:/etc/cdsw/config/cdsw.conf /etc/cdsw/config/cdsw.conf
```
After initialization, the cdsw.conf file includes a generated bootstrap token that allows worker hosts to securely join the cluster. You can get this token by copying the configuration file from master and ensuring it has 600 permissions.

If your hosts have heterogeneous block device configurations, modify the Docker block device settings in the worker host configuration file after you copy it. Worker hosts do not need application block devices, which store the project files and database state, and this configuration option is ignored.
Create /var/lib/cdsw on the worker host. This directory must exist on all worker hosts. Without it, the next step that registers the worker host with the master will fail.
Unlike the master host, the /var/lib/cdsw directory on worker hosts does not need to be mounted to an Application Block Device. It is only used to store client configuration for HDP services on workers.
On the worker host, run the following command to add the host to the cluster:
```
cdsw join
```
This causes the worker hosts to register themselves with the Cloudera Data Science Workbench master host and increase the available pool of resources for workloads.
Return to the master host and verify the host is registered with this command:
```
cdsw status
```