Installing and Using the Worker Node Client from Tarballs (Anywhere by Anyone)


This document is intended to guide system administrators through the process of installing the worker node software and configuring the installed worker node software. Contents of the WN Client can be found here.

If you are installing the OSG WN Client following these instruction, then remember to configure the grid_dir option on your CE - see below.

About This Guide

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

Before Starting

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

Download, Installation and Configuration Procedure

Download the WN Client

Please pick the osg-wn-client tarball that is appropriate for your distribution and architecture. You will find them in .

The latest available the tarballs for OSG 3.3 are:

Install the WN Client

  1. Unpack the tarball.
  2. Move the directory that was created to where you want the tarball WN client to be.
  3. Run osg-post-install (/path/to/client/osg/osg-post-install) to fix the directories in the installation.
    Note that after this, you will not be able to relocate the install again.
  4. Source the setup source /path/to/client/ (or setup.csh depending on the shell)
  5. Download and set up CA certificiates using osg-ca-manage (See OsgCaManage for the available options)
  6. Download CRLs using fetch-crl

Example install (in $HOME/test-install, the /path/to/client/ is $HOME/test-install/osg-wn-client ):

[user@client ~]$ mkdir $HOME/test-install
[user@client ~]$ cd $HOME/test-install
[user@client ~]$ wget
[user@client ~]$ tar xzf osg-wn-client-latest.el6.x86_64.tar.gz
[user@client ~]$ cd osg-wn-client
[user@client ~]$ osg/osg-post-install
[user@client ~]$ .
[user@client ~]$ osg-ca-manage setupCA --url osg
[user@client ~]$ fetch-crl

Unpacking the tarball creates an osg-wn-client subdirectory

Configuring the CE for WN Client tarballs

Using the wn-client software installed from the tarball will require a few changes on the compute element so that the resource's configuration can be correctly reported.

Set grid_dir in the Storage section of your OSG-Configure configs: CE configuration instructions. grid_dir is used as the $OSG_GRID environment variable in running jobs - see EnvironmentVariables. Pilot jobs source $OSG_GRID/ before performing any work. The value set for grid_dir must be the path of the wn-client installation directory. This is the path returned by echo $OSG_LOCATION once you source the setup file created by this installation.


The WN client is a collection of client programs that do not require service startup or shutdown. The only services are osg-update-certs that keeps the CA certificates up-to-date and fetch-crl that keeps the CRLs up-to-date. Following the instructions below you'll add the services to your crontab that will take care to run them periodically until you remove them.

Auto-updating certificates and CRLs

You must create cron jobs to run fetch-crl and osg-update-certs to update your CRLs and certificates automatically.

Here is what they should look like. (Note: fill in <OSG_LOCATION> with the full path of your tarball install, including osg-wn-client that is created by the tarball).

# Cron job to update certs.
# Runs every hour by default, though does not update certs until they're at
# least 24 hours old.  There is a random sleep time for up to 45 minutes (2700
# seconds) to avoid overloading cert servers.
10 * * * *   ( . <OSG_LOCATION>/ && osg-update-certs --random-sleep 2700 --called-from-cron )

# Cron job to update CRLs
# Runs every 6 hours at, 45 minutes +/- 3 minutes.
42 */6 * * *   ( . <OSG_LOCATION>/ && fetch-crl -q -r 360 )

You might want to configure proxy settings in $OSG_LOCATION/etc/fetch-crl.conf.

Starting and Enabling Services

To start the services you must edit your cron with crontab -e and add the lines above.

Stopping and Disabling Services

To stop the services you must edit your cron with crontab -e and remove or comment the lines above.

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.

  1. Submit a job that executes the env command (e.g. Run condor_ce_trace with the -d flag from your HTCondor CE)
  2. Verify that the value of $OSG_GRID is set to the directory of your WN Client installation

How to get Help?

To get assistance please use this Help Procedure.


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

Worker node contents

The worker node may be updated from time to time. As of OSG 3.3.21 in February 2017, the OSG worker node client contains:

  • OSG Certificates
  • curl
  • Fetch CRL
  • FTS client
  • gfal2
  • globus-url-copy (GridFTP client)
  • globus-xio-udt-driver
  • ldapsearch
  • MyProxy
  • osg-system-profiler
  • osg-version
  • UberFTP
  • vo-client (includes /etc/vomses file)
  • VOMS client
  • wget
  • xrdcp

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

[user@client ~]$ rpm -q --requires osg-wn-client

Click here for more details on using RPM to see what was installed

Topic revision: r13 - 09 Mar 2017 - 01:49:00 - MatyasSelmeci
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