1. Introduction

1.1. Purpose of this document

This document introduces users to the U.S. Air Force Research Laboratory (AFRL) DoD Supercomputing Resource Center (DSRC). It provides an overview of available resources, links to important documentation, important policies governing the use of our systems, and other information to help you make efficient and effective use of your allocated hours.

1.2. About the AFRL DSRC

The AFRL DSRC is one of five DSRCs managed by the DoD High Performance Computing Modernization Program (HPCMP). The DSRCs deliver a range of compute-intensive and data-intensive capabilities to the DoD science and technology, test and evaluation, and acquisition engineering communities. Each DSRC operates and maintains major High Performance Computing (HPC) systems and associated infrastructure, such as data storage, in both unclassified and classified environments. The HPCMP provides user support through a centralized help desk and data analysis/visualization group.

The AFRL DSRC is a high performance computing (HPC) facility committed to providing the resources necessary for DoD scientists and engineers to complete their research, development, testing, and evaluation projects. Since our inception in 1996 as part of the HPCMP, we have supported the warfighter by combining powerful computational resources, secure interconnects, and application software with renowned services, expertise, and experience.

1.3. Who our services are for

The HPCMP's services are available to Service and Agency researchers in the Research, Development, Test, and Evaluation (RDT&E) and acquisition engineering communities of the DoD and its respective Services and Agencies, DoD contractors, and University staff working on a DoD research grant.

For more details, see HPCMP Presentation " Who may run on HPCMP Resources?"

1.4. How to get an account

Anyone meeting the above criteria may request an HPCMP account. A Help Desk video is available to guide you through the process of getting an account. To begin the account application process, visit HPC Centers: Obtaining an Account, and follow the instructions presented there.

1.5. Visiting the AFRL DSRC

If you need to travel to the AFRL DSRC, there are security procedures that must be completed BEFORE planning your trip. Please visit our Planning a Visit page and coordinate with your Service/Agency Approval Authority (S/AAA) to ensure that all requirements are met.

2. Policies

2.1. Baseline Configuration (BC) policies

The Baseline Configuration Team sets policies that apply to all HPCMP HPC systems. The BC Policy Compliance Matrix provides an index of all BC policies and compliance status of systems at each DSRC.

2.2. Login node abuse policy

Interactive usage of each of the AFRL DSRC High Performance Computing (HPC) systems is restricted to 15 minutes of process time per core. Any interactive job/process that exceeds this 15-minute-per-core time limit will automatically be killed by system monitoring software. Interactive usage on AFRL DSRC HPC systems should be limited to items such as: program development, including debugging and performance improvement, job preparation, job submission, and the preprocessing and post-processing of data.

AFRL DSRC HPC systems have been tuned for optimal performance in a batch system environment. Excessive interactive usage causes overloading of these systems and leads to considerable degradation of system performance.

2.3. File space management policy

Close management of workspace is a priority of the AFRL DSRC. Each user is provided the following workspace:

$WORKDIR: a "scratch" file system available on each HPC system.
$CENTER: The center-wide file system accessible to all center production machines.

Neither of these file systems is backed up. You are responsible for managing files in your $WORKDIR and $CENTER directories by backing up files to the archive system and deleting unneeded files. Currently, $WORKDIR files older than 21 days and $CENTER files older than 120 days are subject to being purged.

If it is determined as part of the normal purge cycle that files in your $WORKDIR directory must be deleted, we will notify you via email 6 days prior to deletion.

2.4. Maximum session lifetime policy

To provide users with a more secure high performance computing environment, the AFRL DSRC has implemented a limit on the lifetime of all terminal/window sessions. Any idle terminal or window session connections to the AFRL DSRC shall be terminated after 10 hours. Regardless of activity, any terminal or window session connections to the AFRL DSRC shall be terminated after 20 hours. A 15-minute warning message shall be sent to each such session prior to its termination.

2.5. Batch use policy

A single user can run up to 1/2 of the advertised number of system cores on a system in one or more jobs. Once the 1/2 of the system limit is reached, additional jobs will not start or accrue eligible time. Until some of their running jobs finish. The standard limit for run time of jobs is 168 hours. Upon special request, jobs with run times up to 336 hours will be permitted but the users run at risk.

In the case where a system has specialty nodes, large-memory nodes, GPGPU nodes, etc., the scheduler will reserve the specialty nodes for jobs that require them.

Due to limitations in resource checking, the scheduler will allocate cores and memory at the node level. If the requested number of cores and memory is not an even multiple of cores or memory in a node, the resource requests will be increased to the next higher number of nodes. The user will be charged for the use of the entire number of nodes used.

Although every attempt will be made to keep entire systems available, interrupts will occur, and more frequently on systems with larger numbers of nodes. Users should use mechanisms to save the state of their jobs where available (most AFRL DSRC-supported applications can create restart files so that runs do not have to start from the beginning) to protect against system interrupts. Users running long jobs without saving the state of their jobs run at-risk with respect to system interrupts. Use of system-level check pointing is not recommended.

All HPC systems have identical queue names: urgent, debug, HIE, high, frontier, standard, transfer and background; however, each queue has different properties as specified in the table below. Each of these queues is assigned a priority factor within the batch system. The relative priorities of the queues are shown in the table. In addition, jobs requesting more cores will have an additional increase in overall priority relative to the number of cores. Jobs in queues other than background will accrue additional priority based on time in queue. The scheduling of jobs uses job slot-reservation based on these priority factors, and increases system utilization via backfilling while waiting for resources to become available.

AFRL Queue Relative Priority and Limits

Priority	Queue Name	Max Wall Clock Time	Max Cores Per Job	Comments
Highest	urgent	168 Hours	1/2 of the system	HPCMP Urgent projects
	debug	1 Hour		User testing
	high	168 Hours	1/2 of the system	HPCMP High-priority projects
	frontier	168 Hours	1/2 of the system	HPCMP Frontier projects
	standard	168 Hours	1/2 of the system	Normal user jobs
	HIE	24 Hours	2 nodes	Rapid response for interactive work
	transfer	48 Hours	1 core	Data transfer for user jobs
Lowest	background	120 Hours	1 node	Unrestricted access - no allocation charge

In conjunction with the HPCMP Baseline Configuration policy for Common Queue Names across the allocated centers, the AFRL DSRC will honor batch jobs that include the queue name for urgent, high (high-priority) and frontier. AFRL assigns the queue by the project number so if the queue name is omitted the job will be assigned to the correct queue. Note: if the project number does not match the queue, the job will run in the queue defined by the project number, and not by the queue name selected.

Any project with an allocation may submit jobs to the debug, HIE, transfer, or background queue. Projects that have exhausted their allocations will only be able to submit jobs to the background queue. A background job cannot start if there is a foreground job waiting in any queue.

If any job attempts to use more resources than were specified when the job was submitted for batch processing, the scheduling system will automatically kill the job.

2.6. Special request policy

All special requests for allocated HPC resources, including increased priority within queues, increased queue parameters for maximum number of cores and Wall Time, and dedicated use, should be directed to the HPC Help Desk. Request approval will require documentation of the requirement and associated justification, verification by the AFRL DSRC support staff, and approval from the designated authority, as shown in the following table. The AFRL DSRC Director may permit special requests for HPC resources independent of this model for exceptional circumstances.

Approval Authorities for Special Resource Requests

Resource Request	Approval Authority
Up to 10% of an HPC system/complex for 1 week or less	AFRL DSRC Director or Designee
Up to 20% of an HPC system/complex for 1 week or less	S/AAA
Up to 30% of an HPC system/complex for 2 weeks or less	Army/Navy/AF Service Principal on HPC Advisory Panel
Up to 100% of an HPC system/complex for greater than 2 weeks	HPCMP Program Director or Designee

2.7. Account removal policy

AFRL is fully compliant with Baseline Configuration (BC) policy FY13-02 (Data Removal at account closure).

2.8. Communications policy

AFRL is fully compliant with Baseline Configuration (BC) policy FY06-11 (Announcing and Logging Changes). It is the user’s responsibility to ensure that their contact information is kept current in the Portal for Information Environment (pIE). If your information is not current please contact your S/AAA.

2.9. System availability policy

A system will be declared down and made unavailable to users whenever a chronic and/or catastrophic hardware and/or software malfunction or an abnormal computer environment condition exists which could:

1. Result in corruption of user data.
2. Result in unpredictable and/or inaccurate runtime results.
3. Result in a violation of the integrity of the DSRC user environment.
4. Result in damage to the High Performance Computer System(s).

The integrity of the user environment is considered corrupt anytime a user must modify his/her normal operation while logged into the DSRC. Examples of malfunctions are:

1. User home ($HOME) directory not available.
2. User Workspace ($WORKDIR, $JOBDIR) areas not available.
3. If the archive system is unavailable, queues are suspended, but logins are enabled.

When a system is declared down, based on a system administrator's and/or computer operator's judgment, users will be prevented from using the affected system(s) and all existing batch jobs will be prevented from running. Batch jobs held during a "down state" will be run only after the system environment returns to a normal state.

Whenever there is a problem on one of the HPC systems that could be remedied by removing a part of the system from production (an activity called draining), it must first be determined how much of the system will be impacted by the draining in order to brief the necessary levels of management and the user community.

Where the architecture of the HPC system will allow a node to be removed from production with minimal impact to the system as a whole, then the system administrators can make the decision to remove the node with notification to the operators for information. Typically this pertains to cluster system architectures. In some cases, large SMP systems will allow individual CPUs to be downed, and the administrator can determine this and notify operations for information.

Where the architecture of the HPC system will allow significant portions of the system to be removed from production and still allow user production on a large part of the system to continue, then the system administrator along with government and contractor management can make the decision to remove that part of the system. The system should show that domain or SMP node as out of the normal queue for scheduling jobs so that the user community can determine current status. The system administrator will advise operations and the HPC Help Desk of this action.

In cases where $WORKDIR will be unavailable, or a complete system needs to be drained for maintenance, contractor and government director level management will be notified. In cases involving an entire system, the HPC Help Desk will email users of the downtime schedule and schedule for returning the system to production.

2.10. Data import and export policy

This policy outlines the methods available to users to move files into and out of the AFRL DSRC environment. Users accept sole responsibility for the transfer and validation of their data after the transfer.

For cross center data transfers AFRL is fully compliant with Baseline Configuration (BC) policy FY06-14 (Cross-Center File Transfers). For transfers between AFRL and remote locations see the guidance below.

2.10.1. Network file transfers

The preferred transfer method is over the network using the encrypted (Kerberos) file transfer programs scp or ftp. In cases where large numbers of files (> 1000) and/or large amounts of data (> 100 GB) must be transferred, users should contact the HPC Help Desk for assistance in the process.

2.10.2. Reading/Writing media

There are currently no facilities or provisions as available to import or export user data on tape with the resources of the mass storage/archival system.

AFRL Staff will accept hard disk media for use in transferring large amounts of data. Disks will be scanned and then mounted to local systems so that AFRL Staff can load or unload data. The Disk will then be provided back to the user. Please contact the HPC Help Desk for assistance in the process.

2.11. Account sharing policy

Users are responsible for all passwords, accounts, YubiKeys, and associated PINs issued to them. Users are not to share their passwords, accounts, YubiKeys, or PINs with any other individual for any reason. Doing so is a violation of the contract that users are required to sign in order to obtain access to DoD High Performance Computing Modernization Program (HPCMP) computational resources.

Upon discovery/notification of a violation of the above policy, the following actions will be taken:

1. The account (i.e., username) will be disabled. No further logins will be permitted.
2. All account assets will be frozen. File and directory permissions will be set such that no other users can access the account assets.
3. Any executing jobs will be permitted to complete; however, any jobs residing in input queues will be deleted.
4. The Service/Agency Approval Authority (S/AAA) who authorized the account will be notified of the policy violation and the actions taken.

Upon the first occurrence of a violation of the above policy, the S/AAA has the authority to request that the account be re-enabled. Upon the occurrence of a second or subsequent violation of the above policy, the account will only be re-enabled if the user's supervisory chain of command, S/AAA, and the High Performance Computing Modernization Office (HPCMO) all agree that the account should be re-enabled.

The disposition of account assets will be determined by the S/AAA. The S/AAA can:

1. Request that account assets be transferred to another account.
2. Request that account assets be returned to the user.
3. Request that account assets be deleted and the account closed.

If there are associate investigators who need access to AFRL DSRC computer resources, we encourage them to apply for an account. Separate account holders may access common project data as authorized by the project leader.

3. Available resources

3.1. HPC systems

The AFRL DSRC unclassified HPC systems are accessible through the Defense Research and Engineering Network (DREN) to all active users. Our current HPC systems include:

Mustang is an HPE/SGI 8600 system. It has 1,128 standard compute nodes, 24 large-memory compute nodes, and 24 GPU compute nodes (a total of 1,176 compute nodes or 56,448 compute cores). It is rated at 4.87 peak PFLOPS. For more information about Mustang, visit our hardware page.

3.2. Data storage

3.2.1. File systems

Each HPC system has several file systems available for storing user data. Your personal directories on these file systems are commonly referenced via the $HOME, $WORKDIR, $CENTER, and $ARCHIVE_HOME environment variables. Other file systems may be available as well.

File System Environment Variables

Environment Variable	Description
$HOME	Your home directory on the system
$WORKDIR	Your temporary work directory on a high-capacity, high-speed scratch file system used by running jobs
$CENTER	Your short-term (120-day) storage directory on the Center-Wide File System (CWFS)
$ARCHIVE_HOME	Your archival directory on the archive server

For details about the specific file systems on each system, see the system user guides on the documentation page.

3.2.2. Archive system

All of our HPC systems have access to an online archival system, which provides long term storage for users' files on a petascale robotic tape library system. A 100-TB disk cache frontends the tape file system and temporarily holds files while they are being transferred to or from tape.

For information on using the archive server, see the Archive User Guide.

3.3. Computing environment

To ensure a consistent computing environment and user experience on all HPCMP HPC systems, all systems follow a standard configuration baseline. For more information on the policies defining the baseline configuration, see the Baseline Configuration Compliance Matrix. All systems run variants of the Linux operating system, but the computing environment varies by vendor and architecture due to vendor-specific enhancements.

3.3.1. Software

Each HPC system hosts a large variety of compiler environments, math libraries, programming tools, and third-party analysis applications which are available via loadable software modules. A list of software is available on the software page, or for more up-to-date software information, use the module commands on the HPC systems. Specific details of the computing environment on each HPC system are discussed in the system user guides, available on the documentation page.

To request additional software or to request access to restricted software, please contact the HPC Help Desk at help@helpdesk.hpc.mil.

3.3.2. Bring your own code

While all HPCMP HPC systems offer a diversity of open source, commercial and government software, there are times when we don't support the application codes and tools needed for specific projects. The following information describes a convenient way to utilize your own software on our systems.

Our HPC systems provide you with adequate file space to store your codes. Data stored in your home directory ($HOME) will be backed up on a periodic basis. If you need more home directory space, you may submit a request to the HPC Help Desk at help@helpdesk.hpc.mil. For more details on home directories, see to the Baseline Configuration (BC) policy FY12-01 (Minimum Home Directory Size and Backup Schedule).

If you need to share an application among multiple users, BC policy FY10-07 (Common Location to Maintain Codes) explains how to create a common location on the $PROJECTS_HOME file system, to place applications and codes without using home directories or scrubbed scratch space. To request a new "project directory," please provide the following information to the HPC Help Desk:

• Desired DSRC system where a project directory is being requested.
• POC Information: Name of the sponsor of the project directory, user name, and contact information.
• Short Description of Project: Short summary of the project describing the need for a project directory.
• Desired Directory Name: This will be the name of the directory created under $PROJECTS_HOME.
• Is the code/data in the project directory restricted (e.g. ITAR, etc.)?
• Desired Directory Owner: The user name to be assigned ownership of the directory.
• Desired Directory Group: The group name to be assigned to the directory.
  (New group names must be 8 characters or less)
• Additional users to be added to the group.

If the POC for the project directory ceases being an account holder on the system, project directories will be handled according to the user data retention policies of the center.

Once the project directory is created, you can install software (custom or open source) in this directory. Then, depending on requirements, you can set file and/or directory permissions to allow any combination of group read, write, and execute privileges. Since this directory is fully owned by the POC, he or she can even make use of different groups within subdirectories to provide finer granularity of permissions.

Users are expected to ensure that any software or data that is placed on HPCMP systems is protected according to any external restrictions on the data. Users are also responsible for ensuring no unauthorized or malicious software is introduced to the HPCMP environment.

For installations involving restricted software, it is your responsibility to set up group permissions on the directories and to protect the data. It is crucially important to note that there are users on the HPCMP systems who are not authorized to access restricted data. You may not run servers or use software that communicates to a remote system without prior authorization.

If you need help porting or installing your code, the HPC Help Desk provides a "Code Assist" team that specializes in helping users with installation and configuration issues for user supplied codes. To get help, simply contact the HPC Help Desk and open a ticket.

Please contact the HPC Help Desk help@helpdesk.hpc.mil to discuss any special requirements.

3.3.3. Batch schedulers

Our HPC systems use various batch schedulers to manage user jobs and system resources. Basic instructions and examples for using the scheduler on each system can be found in the system user guides. More extensive information can be found in the Scheduler Guides. These documents are available on the documentation page.

Schedulers place user jobs into different queues based on the project associated with the user account. Most users only have access to the debug, standard, transfer, HIE, and background queues, but other queues may be available to you depending on your project. For more information about the queues on a system, see the Scheduler Guides.

3.3.4. Advance Reservation Service (ARS)

Another way to schedule jobs is through the Advance Reservation Service. This service allows users to reserve resources for use at specific times and for specific durations. The ARS works in tandem with the batch scheduler to ensure that your job runs at the scheduled time, and that all required resources (i.e., nodes, licenses, etc.) are available when your job begins. For information on using the ARS, see the ARS User Guide.

3.4. HPC Portal

The HPC Portal provides a suite of custom web applications, allowing you to access a command line, manage files, and submit and manage jobs from a browser. It also supports pre/post-processing and data visualization by making DSRC-hosted desktop applications accessible over the web. For more information about the HPC Portal, see the HPC Portal page on the HPC Centers website.

3.5. Secure Remote Desktop (SRD)

The Secure Remote Desktop enables users to launch a gnome desktop on an HPC system via a downloadable Java interface client. This desktop is then piped to the user's local workstation (Linux, Mac, or Windows) for display. Once the desktop is launched, a user may run any software application installed on the HPC system. For information on using SRD, or to download the client, see the Secure Remote Desktop page on the DAAC website.

3.6. Network connectivity

The AFRL DSRC is a primary node on the Defense Research and Engineering Network (DREN), which provides up to 40-Gb/sec service to DoD HPCMP centers nationwide across a 100-Gb/sec backbone. We connect to the DREN via a 10-Gb/sec circuit linking us to the DREN backbone.

The DSRC's local network consists of a 40-Gb/sec fault-tolerant backbone with 10-Gb/sec connections to the HPC and archive systems.

4. How to access our systems

The HPCMP uses a network authentication protocol called Kerberos to authenticate user access to our HPC systems. Before you can login, you must download and install an HPCMP Kerberos client kit on your local system. For information about downloading and using these kits, visit HPC Centers: Kerberos & Authentication, and click on the tab for your platform. There you will find instructions for downloading and installing the kit, getting a ticket, and logging in.

After installing and configuring a Kerberos client kit, you can access our HPC systems via standard Kerberized commands, such as ssh. File transfers between local and remote systems can be accomplished via the scp, mpscp, or scampi commands. For additional information on using the Kerberos tools, see the Kerberos User Guide or review the tutorial video on Logging into an HPC System. Instructions for logging into each system can be found in the system user guides on the documentation page.

Another way to access the HPC systems is through the HPC Portal. For information on using the portal, visit HPC Centers: HPC Portal. You may also wish to review the HPC Portal demonstration videos. To log into the portal, click on the link for the center where your account is located.

5. How to get help

For almost any issue, the first place you should turn for help is the HPC Help Desk. You can email the Help Desk at help@helpdesk.hpc.mil. You can also contact the Help Desk via phone, fax, DSN, or even traditional mail. Full contact for the Help Desk is available on HPC Centers: Technical and Customer Support. The Help Desk can assist with a wide array of technical issues related to your account and your use of our systems. The Help Desk can also assist in connecting you with various special-purpose groups to address your particular need.

5.1. Productivity Enhancement and Training (PET)

The PET initiative gives users access to computational experts in many HPC technology areas. These HPC application experts help HPC users become more productive using HPCMP supercomputers. The PET initiative also leverages the expertise of academia and industry experts in new technologies and provides training on HPC-related topics. Help in specific computational technology areas is available providing a wide range of expertise including algorithm development and implementation, code porting and development, performance analysis, application and I/O optimization, accelerator programming, preprocessing and grid generation, workflows, in-situ visualization, and data analytics.

To learn more about PET, see HPC Centers: Advanced User Support. To request PET assistance, send email to PET@hpc.mil.

5.2. User Advocacy Group (UAG)

The UAG provides a forum for users of HPCMP resources to influence policies and practices of the Program; to facilitate the exchange of information between the user community and the HPCMP; to serve as an advocate for HPCMP users; and to advise the HPC Modernization Program Office on policy and operational matters related the HPCMP.

To learn more about the UAG, see HPC Centers: User Advocacy Group(PKI required). To contact the UAG, send email to hpc-uag@hpc.mil.

5.3. Baseline Configuration Team (BCT)

The BCT is tasked to define a common set of capabilities and functions so that users can work more productively and collaboratively when using the HPC resources at multiple computing centers. To accomplish this, the BCT passes policies which collectively create a configuration baseline for all HPC systems.

To learn more about the BCT and its policies, see HPC Centers: Baseline Configuration. To contact the BCT, send email to BCTinput@afrl.hpc.mil.

5.4. Computational Research and Engineering Acquisition Tools and Environments (CREATE)

The CREATE program provides tools to enhance the productivity of the DoD acquisition engineering workforce by providing high fidelity design and analysis tools with capabilities greater than today's tools, reducing the acquisition development and test process cycle. CREATE projects provide enhanced engineering design tools for the DoD HPC community.

To learn more about CREATE, visit the HPCMP Create page or contact the CREATE Program Office at CREATE@hpc.mil. You may also want to access the CREATE Community site (Registration and PKI required).

5.5. Data Analysis and Assessment Center (DAAC)

The DAAC serves the needs of DoD HPCMP scientists to analyze an ever increasing volume and complexity of data. Their mission is to put visualization and analysis tools and services into the hands of every user.

For more information about DAAC, visit the DAAC website. To request assistance from DAAC, send email to support@daac.hpc.mil.