Installing and Using the Worker Node Client From RPMs

The OSG Worker Node Client is a collection of software components that is expected to be added to every worker node that can run OSG jobs. It provides a common environment and a minimal set of common tools that all OSG jobs can expect to use. See the reference section below for contents of the Worker Node Client.

It is possible to install the Worker Node Client software in a variety of ways, depending on what works best for distributing and managing software at your site:

Install using RPMs and yum (this guide) - useful when managing your worker nodes with a tool (e.g., Puppet, Chef) that can automate RPM installs
Install using a tarball - useful when installing onto a shared filesystem for distribution to worker nodes
Use from OASIS - useful when worker nodes already mount OASIS on your worker nodes

This document is intended to guide system administrators through the process of configuring a site to make the Worker Node Client software available from an RPM.

Before Starting

As with all OSG software installations, there are some one-time (per host) steps to prepare in advance:

Ensure the host has a supported operating system
Obtain root access to the host
Prepare the required Yum repositories
Install CA certificates

Install the Worker Node Client

Install the Worker Node Client RPM:

yum install osg-wn-client

Services

Fetch-CRL is the only service required to support the WN Client.

Software	Service name	Notes
Fetch CRL	On EL6 and EL7: `fetch-crl-boot` and `fetch-crl-cron`
On EL5: `fetch-crl3-boot` and `fetch-crl3-cron`	See CA documentation for more info

Note

fetch-crl-boot will begin fetching CRLS, which can take a few minutes and fail on transient errors. You can add configuration to ignore these transient errors in /etc/fetch-crl.conf for EL6 or EL7 machines or /etc/fetch-crl3.conf for EL5 machines:

noerrors

As a reminder, here are common service commands (all run as root):

To …	Run the command …
Start a service	`service SERVICE-NAME start`
Stop a service	`service SERVICE-NAME stop`
Enable a service to start during boot	`chkconfig SERVICE-NAME on`
Disable a service from starting during boot	`chkconfig SERVICE-NAME off`

Validing the Worker Node Client

To verify functionality of the worker node client, you will need to submit a test job against your CE and verify the job’s output.

Submit a job that executes the env command (e.g. Run condor_ce_trace with the -d flag from your HTCondor CE)
Verify that the value of OSG_GRID is set to /etc/osg/wn-client

How to get Help?

To get assistance please use this Help Procedure.

Reference

Please see the documentation on using yum and RPM, the best practices for using yum to install software, and using yum repositories.

To see the currently installed version of the worker node package, run the following command:

rpm -q --requires osg-wn-client

See our yum basics guide for more details on using RPM to see what was installed.