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End-to-end Provenance Traceability and Reproducibility Through "Palletized'' Simulation Data

Lofstead, Gerald F.; Younge, Andrew J.; Baker, Joshua B.

Trusting simulation output is crucial for Sandia's mission objectives. We rely on these simulations to perform our high-consequence mission tasks given our treaty obligations. Other science and modelling needs, while they may not be high-consequence, still require the strongest levels of trust to enable using the result as the foundation for both practical applications and future research. To this end, the computing community has developed work- flow and provenance systems to aid in both automating simulation and modelling execution, but to also aid in determining exactly how was some output created so that conclusions can be drawn from the data. Current approaches for workflows and provenance systems are all at the user level and have little to no system level support making them fragile, difficult to use, and incomplete solutions. The introduction of container technology is a first step towards encapsulating and tracking artifacts used in creating data and resulting insights, but their current implementation is focused solely on making it easy to deploy an application in an isolated "sandbox" and maintaining a strictly read-only mode to avoid any potential changes to the application. All storage activities are still using the system-level shared storage. This project was an initial exploration into extending the container concept to also include storage and to use writable containers, auto generated by the system, as a way to link the contained data back to the simulation and input deck used to create it.

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TYPE SAND Report YEAR 2018
OSTIDOI

Delta: Data Reduction for Integrated Application Workflows

Lofstead, Gerald F.; Jean-Baptiste, Gregory J.; Oldfield, Ron A.

Integrated Application Workflows (IAWs) run multiple simulation workflow components con- currently on an HPC resource connecting these components using compute area resources and compensating for any performance or data processing rate mismatches. These IAWs require high frequency and high volume data transfers between compute nodes and staging area nodes during the lifetime of a large parallel computation. The available network band- width between the two areas may not be enough to efficiently support the data movement. As the processing power available to compute resources increases, the requirements for this data transfer will become more difficult to satisfy and perhaps will not be satisfiable at all since network capabilities are not expanding at a comparable rate. Furthermore, energy consumption in HPC environments is expected to grow by an order of magnitude as exas- cale systems become a reality. The energy cost of moving large amounts of data frequently will contribute to this issue. It is necessary to reduce the volume of data without reducing the quality of data when it is being processed and analyzed. Delta resolves the issue by addressing the lifetime data transfer operations. Delta removes subsequent identical copies of already transmitted data during transfers and restores those copies once the data has reached the destination. Delta is able to identify duplicated information and determine the most space efficient way to represent it. Initial tests show about 50% reduction in data movement while maintaining the same data quality and transmission frequency.

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TYPE SAND Report YEAR 2015
OSTIDOI

CCC7 Cielo Report

Lofstead, Gerald F.

ASC Level 2 Milestone FY 2013 continuation. L2 revealed memory pressures from using in situ analysis; Developed tools to determine memory usage; Reduced memory footprint by more than 50%.

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TYPE Other Report YEAR 2015
OSTIDOI

Demonstration of a Legacy Application's Path to Exascale - ASC L2 Milestone 4467

Barrett, Brian B.; Kelly, Suzanne M.; Klundt, Ruth A.; Laros, James H.; Leung, Vitus J.; Levenhagen, Michael J.; Lofstead, Gerald F.; Moreland, Kenneth D.; Oldfield, Ron A.; Pedretti, Kevin P.; Rodrigues, Arun; Barrett, Richard F.; Ward, Harry L.; Vandyke, John P.; Vaughan, Courtenay T.; Wheeler, Kyle B.; Brandt, James M.; Brightwell, Ronald B.; Curry, Matthew L.; Fabian, Nathan D.; Ferreira, Kurt; Gentile, Ann C.; Hemmert, Karl S.

Abstract not provided.

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TYPE Presentation YEAR 2012
OSTI

Report of experiments and evidence for ASC L2 milestone 4467 : demonstration of a legacy application's path to exascale

Barrett, Brian B.; Kelly, Suzanne M.; Klundt, Ruth A.; Laros, James H.; Leung, Vitus J.; Levenhagen, Michael J.; Lofstead, Gerald F.; Moreland, Kenneth D.; Oldfield, Ron A.; Pedretti, Kevin P.; Rodrigues, Arun; Barrett, Richard F.; Ward, Harry L.; Vandyke, John P.; Vaughan, Courtenay T.; Wheeler, Kyle B.; Brandt, James M.; Brightwell, Ronald B.; Curry, Matthew L.; Fabian, Nathan D.; Ferreira, Kurt; Gentile, Ann C.; Hemmert, Karl S.

This report documents thirteen of Sandia's contributions to the Computational Systems and Software Environment (CSSE) within the Advanced Simulation and Computing (ASC) program between fiscal years 2009 and 2012. It describes their impact on ASC applications. Most contributions are implemented in lower software levels allowing for application improvement without source code changes. Improvements are identified in such areas as reduced run time, characterizing power usage, and Input/Output (I/O). Other experiments are more forward looking, demonstrating potential bottlenecks using mini-application versions of the legacy codes and simulating their network activity on Exascale-class hardware. The purpose of this report is to prove that the team has completed milestone 4467-Demonstration of a Legacy Application's Path to Exascale. Cielo is expected to be the last capability system on which existing ASC codes can run without significant modifications. This assertion will be tested to determine where the breaking point is for an existing highly scalable application. The goal is to stretch the performance boundaries of the application by applying recent CSSE RD in areas such as resilience, power, I/O, visualization services, SMARTMAP, lightweight LWKs, virtualization, simulation, and feedback loops. Dedicated system time reservations and/or CCC allocations will be used to quantify the impact of system-level changes to extend the life and performance of the ASC code base. Finally, a simulation of anticipated exascale-class hardware will be performed using SST to supplement the calculations. Determine where the breaking point is for an existing highly scalable application: Chapter 15 presented the CSSE work that sought to identify the breaking point in two ASC legacy applications-Charon and CTH. Their mini-app versions were also employed to complete the task. There is no single breaking point as more than one issue was found with the two codes. The results were that applications can expect to encounter performance issues related to the computing environment, system software, and algorithms. Careful profiling of runtime performance will be needed to identify the source of an issue, in strong combination with knowledge of system software and application source code.

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TYPE SAND Report YEAR 2012
OSTIDOI

Resilient data staging through MxN distributed transactions

Lofstead, Gerald F.; Oldfield, Ron A.

Scientific computing-driven discoveries are frequently driven from workflows that use persistent storage as a staging area for data between operations. With the bad and progressively worse bandwidth vs. data size issues as we continue towards exascale, eliminating persistent storage through techniques like data staging will both enable these workflows to continue online, but also enable more interactive workflows reducing the time to scientific discoveries. Data staging has shown to be an effective way for applications running on high-end computing platforms to offload expensive I/O operations and to manage the tremendous amounts of data they produce. This data staging approach, however, lacks the ACID style guarantees traditional straight-to-disk methods provide. Distributed transactions are a proven way to add ACID properties to data movements, however distributed transactions follow 1xN data movement semantics, where our highly parallel HPC environments employ MxN data movement semantics. In this paper we present a novel protocol that extends distributed transaction terminology to include MxN semantics which allows our data staging areas to benefit from ACID properties. We show that with our protocol we can provide resilient data staging with a limited performance penalty over current data staging implementations.

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TYPE SAND Report YEAR 2011
OSTIDOI
83 Results
83 Results