Changes

== Job Submission ==

== Job policy ==

=== ClassAds ===

=== ClassAds ===

The Statistics Cluster is equipped with a powerful job queuing system called [http://research.cs.wisc.edu/htcondor/ Condor]. This framework provides efficient use of resources by matching user needs to the available resources by taking into account both the priorities for the hardware and the preferences of the job. Matching resource requests to resource offers is accomplished through the <b><i>ClassAds</i></b> mechanism. Each virtual machine publishes its parameters as a kind of <u>class</u>ified <u>ad</u>vertisement to attract jobs. A job submitted to Condor for scheduling may list its requirements and preferences.

The Statistics Cluster is equipped with a powerful job queuing system called [http://research.cs.wisc.edu/htcondor/ Condor]. This framework provides efficient use of resources by matching user needs to the available resources by taking into account both the priorities for the hardware and the preferences of the job. Matching resource requests to resource offers is accomplished through the <b><i>ClassAds</i></b> mechanism. Each virtual machine publishes its parameters as a kind of <u>class</u>ified <u>ad</u>vertisement to attract jobs. A job submitted to Condor for scheduling may list its requirements and preferences.

=== User Priority ===

=== User Priority ===

When jobs are submitted, Condor must allocate available resources to the requesting users. It does so by using a value called <i>userprio</i> (user priority). The lower the value of <i>userprio</i> the higher the priority for that user. For example, a user with <i>userprio</i> 5 has a higher priority than a user with <i>userprio</i> 50. The share of available machines that a user should be allocated is continuously calculated by Condor and changes based on the resource use of the individual. If a user has more machines allocated than the <i>userprio</i>, then the value will worsen by increasing over time. If a user has less machines allocated than the <i>userprio</i>, then it will improve by decreasing over time. This is how Condor fairly distributes machine resources to users.

When jobs are submitted, Condor must allocate available resources to the requesting users. In addition to adhering to the Accounting Groups, it does so by using a value called <i>userprio</i> (user priority). The lower the value of <i>userprio</i> the higher the priority for that user. For example, a user with <i>userprio</i> 5 has a higher priority than a user with <i>userprio</i> 50. The share of available machines that a user should be allocated is continuously calculated by Condor and changes based on the resource use of the individual. If a user has more machines allocated than the <i>userprio</i>, then the value will worsen by increasing over time. If a user has less machines allocated than the <i>userprio</i>, then it will improve by decreasing over time. This is how Condor fairly distributes machine resources to users.

On the stats cluster, each student and faculty member are given a specific <i>priority factor</i> of 1000. This is used to calculate the effective priority of a user. Any non-UConn user of the cluster has a priority factor of 2000 so that priority is given to UConn users.  As users claim machines their effective priority will adjust accordingly.

On the stats cluster, each student and faculty member are given a specific <i>priority factor</i> of 1000. This is used to calculate the effective priority of a user. Any non-UConn user of the cluster has a priority factor of 2000 so that priority is given to UConn users.  As users claim machines their effective priority will adjust accordingly.

=== Submit File ===

=== Submit File ===

</pre>

</pre>

A simple description file goes as follows:

A simple, standard group description file goes as follows:

<pre>Requirements = ParallelSchedulingGroup == "stats group"

<pre>Requirements = ParallelSchedulingGroup == "stats group"

when_to_transfer_output = ON_EXIT

when_to_transfer_output = ON_EXIT

on_exit_remove = (ExitCode =?= 0)

on_exit_remove = (ExitCode =?= 0)

transfer_output_remaps = "<default_filename> = /home/<username>/jobs/<updated_filename>"

transfer_output_remaps = "<default_output_filename> = /home/<username>/jobs/<updated_output_path_and_filename>"

Queue 50</pre>

Queue 50</pre>

Most of the variables are self-explanatory. The <b>executable</b> is a path to the program binary or executable script. The shown use of the <b>requirements</b> variable is important here to constrain job assignment to Statistics Cluster nodes only. All available nodes are tagged with <i>ParallelSchedulingGroup</i> variable in the ClassAds, so this is an effective way to direct execution to particular cluster segments. The <b>output</b>, <b>error</b> and <b>log</b> create the respective records for each job numbered by Condor with the <i>$(Process)</i> variable. A detailed example of a job is available [http://gryphn.phys.uconn.edu/statswiki/index.php/Example_Jobs here]. If your job requires input from another file, the following can be added above the output line:

Most of the variables are self-explanatory. The <b>executable</b> is a path to the program binary or executable script. The shown use of the <b>requirements</b> variable is important here to constrain job assignment to Statistics Cluster nodes only. All available nodes are tagged with <i>ParallelSchedulingGroup</i> variable in the ClassAds, so this is an effective way to direct execution to particular cluster segments. The <b>output</b>, <b>error</b> and <b>log</b> create the respective records for each job numbered by Condor with the <i>$(Process)</i> variable. A detailed example of a job is available [http://gryphn.phys.uconn.edu/statswiki/index.php/Example_Jobs here].

 

If your job requires input from another file, the following can be added above the output line:

<pre>

<pre>

input = input.file

input = input.file

For optimal allocation of resources, <b><i>serial jobs ought to be submitted to Condor as well</i></b>. This is accomplished by omitting the number of job instances leaving only the directive <i>Queue</i> in the last line of the job description file outlined above. Obviously, <i>$(Process)</i> placeholder is no longer necessary since there will be no enumeration of output files.

For optimal allocation of resources, <b><i>serial jobs ought to be submitted to Condor as well</i></b>. This is accomplished by omitting the number of job instances leaving only the directive <i>Queue</i> in the last line of the job description file outlined above. Obviously, <i>$(Process)</i> placeholder is no longer necessary since there will be no enumeration of output files.

== Job policy ==

=== AccountingGroup Example ===

The policy for standard jobs is to allow jobs to run a maximum of 24 hours. Long jobs are allowed to run for 48 hours before being killed but these jobs must have the following included in their submit file

 

+AccountingGroup = "group_statistics_testjob.username"

+AccountingGroup = “group_statistics_longjob.username”

Log      = myprog.log

Queue #

Queue 50</pre>

</pre>

Make sure that the last line in your submit file is "Queue <number>". Users are expected to adjust their jobs to meet these run time requirements. Jobs that go beyond these limits can be removed by administrators.

Remember to replace ".username" with your stats cluster username. This sample submit script can be used for shortjob and longjob groups by replacing "testjob" with either "shortjob" or "longjob".