Scripting Grid Engine Administrative Tasks Made Simple

By Sinisa Veseli

Grid Engine (GE) is becoming increasingly popular software for distributed resource management. Although it comes with a GUI that can be used for various administrative and configuration tasks, the fact that all of those tasks can be scripted is very appealing. The GE Scripting HOWTO document already contains a few examples to get one started, but I wanted to further illustrate the usefulness of this GE feature with a simple example of a utility that modifies shell start mode for all queues in the system:

#!/bin/sh

# Utility to modify shell start mode for all GE queues.
# Usage: modify_shell_start_mode.sh 
#  can be one of unix_behavior, posix_compliant or script_from_stdin

# Temporary config file.
tmpFile=/tmp/sge_q.$$

# Get new mode.
newMode=$1

# Modify all known queues.
for q in `qconf -sql`; do
# Prepare queue modification.
echo "Modifying queue: $q"
cmd=”qconf -sq $q | sed 's?shell_start_mode.*?shell_start_mode $newMode?' > $tmpFile”
eval $cmd

# Modify queue.
qconf -Mq $tmpFile

# Cleanup.
rm -f $tmpFile
done

Using the above script one can quickly modify the variable for all queues without having to go through the manual configuration steps.

The basic approach of 1) preparing new configuration file by modifying the current object configuration, and 2) reconfiguring GE using the prepared file, works for a wide variety of tasks. There are cases, however, in which the desired object does not exist and has to be added. Those cases can be handled by modifying the EDITOR environment variable and invoking the appropriate qconf command. For example, here is a simple script that creates set of new queues from the command line:

#!/bin/sh

# Utility to add new queues automatically.
# Usage: add_queue.sh   …

# Force non-interactive mode.
EDITOR=/bin/cat; export EDITOR

# Get new queue names.
newQueues=$@

# Add new queues.
for q in $newQueues; do
echo "Adding queue: $q"
qconf -aq $q
done

Utilities like the ones shown here get written once and usually quickly become indispensable tools for experienced GE administrators.