A Path to Operating System and Runtime Support for Extreme Scale Tools

In this project, we cast distributed resource access as operations on files in a global name space and developed a common, scalable solution for group operations on distributed processes and files. The resulting solution enables tool and middleware developers to quickly create new scalable software or easily improve the scalability of existing software. The cornerstone of the project was the design of a new programming idiom called group file operations that eliminates iterative behavior when a single process must apply the same set of file operations to a group of related files. To demonstrate our novel and scalable ideas for group file operations and global name space composition, we developed a group file system called TBON-FS that leverages a tree-based overlay network (TBON), specifically MRNet, for logarithmic communication and distributed data aggregation. We also developed proc++, a new synthetic file system co-designed for use in scalable group file operations. Over the course of the project, we evaluated the utility and performance of group file operations, global name space composition, TBON-FS, and proc++ in three case studies. The first study focused on the ease in using group file operations and TBON-FS to quickly develop several new scalable tools for distributed system administration and monitoring. The second study evaluated the integration of group file operation and TBON-FS within the Ganglia Distributed Monitoring System to improve its scalability for clusters. The final study involved the integration of group file operations, TBON-FS, and proc++ within TotalView, the widely-used parallel debugger. For this project, the work of the Oak Ridge National Laboratory (ORNL) team occurred primarily in two directions: bringing the MRNet tree-based overlay network (TBON) implementation to the Cray XT platform, and investigating techniques for predicting the performance of MRNet topologies on such systems. Rogue Wave Software (RWS), formerly TotalView Technologies Inc., worked with the University ofWisconsin (UW) team on the design and prototyping of a scalable version of the TotalView debugger. RWS assisted UW with their "proc++" design effort. RWS assisted UW with strategy for integrating proc++ into TotalView

Implementation of Electronic Adherence Monitors and Associated Interventions for Routine HIV Antiretroviral Therapy in Uganda: Promising Findings

BackgroundHigh, sustained adherence is critical for achieving the individual and public health benefits of HIV antiretroviral therapy (ART). Electronic monitors provide detailed adherence information and can enable real-time interventions; however, their use to date has largely been confined to research. This pilot study (NCT03825952) sought to understand feasibility and acceptability a relatively low-cost version of this technology and associated interventions for routine ART delivery in sub-Saharan Africa.MethodsWe provided two ART clinics in rural, southwestern Uganda with electronic adherence monitors for data-informed counseling as well as optional SMS messages to clients and/or social supporters (daily or triggered by missed or delayed doses) and/or an alarm. Clinic and ART client experiences were observed for 3 months per client, including time and motion studies. Qualitative interviews among clients, clinicians, and healthcare administrators were informed by the Consolidated Framework for Implementation Research.ResultsFifty-one ART clients were enrolled; 57% were male and the median age was 34 years. Choice of associated intervention varied among participants. The median number of visits during follow-up was two per client. Counselors reviewed the adherence data with 90% of clients at least once; 67% reviewed data at all visits. Average adherence was 94%; four clients had adherence gaps >1 week. Acceptability was high; all but one client found the monitor "very useful” and all found SMS “very useful.” Clinic visits among clients with the intervention lasted 4 min longer on average than those in standard care. The monitors and daily SMS generally functioned well, although excess SMS were triggered, primarily due to cellular network delays. Overall, participants felt the technology improved adherence, clinic experiences, and clinician-client relationships. Few worried about stigma and privacy. Cost was a concern for implementation, particularly at scale.ConclusionWe successfully implemented a relatively low-cost electronic ART adherence monitor and associated interventions for routine care in rural Uganda. Feasibility and acceptability were generally high, and individuals were identified who could benefit from adherence support. Future work should involve longitudinal follow-up of diverse populations, clinical outcomes, and detailed cost-effectiveness analysis to help drive policy decisions around the uptake of this technology for routine clinical care.Clinical Trial Registrationidentifier: NCT03825952

A Path to Operating System and Runtime Support for Extreme Scale Tools

In this project, we cast distributed resource access as operations on files in a global name space and developed a common, scalable solution for group operations on distributed processes and files. The resulting solution enables tool and middleware developers to quickly create new scalable software or easily improve the scalability of existing software. The cornerstone of the project was the design of a new programming idiom called group file operations that eliminates iterative behavior when a single process must apply the same set of file operations to a group of related files. To demonstrate our novel and scalable ideas for group file operations and global name space composition, we developed a group file system called TBON-FS that leverages a tree-based overlay network (TBON), specifically MRNet, for logarithmic communication and distributed data aggregation. We also developed proc++, a new synthetic file system co-designed for use in scalable group file operations. Over the course of the project, we evaluated the utility and performance of group file operations, global name space composition, TBON-FS, and proc++ in three case studies. The first study focused on the ease in using group file operations and TBON-FS to quickly develop several new scalable tools for distributed system administration and monitoring. The second study evaluated the integration of group file operation and TBON-FS within the Ganglia Distributed Monitoring System to improve its scalability for clusters. The final study involved the integration of group file operations, TBON-FS, and proc++ within TotalView, the widely-used parallel debugger. For this project, the work of the Oak Ridge National Laboratory (ORNL) team occurred primarily in two directions: bringing the MRNet tree-based overlay network (TBON) implementation to the Cray XT platform, and investigating techniques for predicting the performance of MRNet topologies on such systems. Rogue Wave Software (RWS), formerly TotalView Technologies Inc., worked with the University ofWisconsin (UW) team on the design and prototyping of a scalable version of the TotalView debugger. RWS assisted UW with their "proc++" design effort. RWS assisted UW with strategy for integrating proc++ into TotalView