1. Priority Research Direction (use one slide for each) Key challenges -Fault understanding (RAS), modeling, prediction -Fault isolation/confinement + local management -Resilience new tech (Flash mem, virtualization) -Resilience power consumption |heterogeneity -Resilient Storage and file systems -Extending applicability of checkpoint -Replication (backup core) Rollback recovery -Fault recovery Fault avoidance (migration) -Transparent Application guided -Resilience and programming/execution models -Resilient apps. & algo. possibly with OS support -Language / compiler support for resilience -Experimental env. to stress & compare solutions barriers and gaps: -Cope with a continuous flow of different errors-faults including soft errors (silent or not) -Current techniques (ckpt/rest) will not scale -Limits of Storage and file systems -Software stack is not fault aware -Provide Verification of large, long time scale simulation Better consistency in error/fault management across software layers [S] System + Application interactions to manage errors and fault [M] Naturally Resilient system [M] and application software [L] -Resilience is a key issue for the Exascale community -Enable tightly coupled applications to run longer -Better resilience will provide better efficiency (full system) Summary of research direction Potential impact on software component Potential impact on usability, capability, and breadth of community

2. 4.x Resilience Resilience is a critical issue to achieve high apps. throughput 2010201120122013201420152016201720182019 Net Throughput 10 Peta 1 Exa 100 Peta All software should be fault aware and consistent Fault oblivious Applications Application should be able to dynamically handle errors Extend applicability of checkpointing -- IO caching (e.g., NAND) -- New FT protocols System level fault-tolerance -- prediction for time optimal checkpointing and migration -- isolation and local recovery/management Improved hardware and software reliability -- better RAS collection and analysis (root cause) -- Integration LongMediumShort MTBF=<1hMTBF=<10m MTBF=<10h (based on DARPA report) MTBF=day MTBF=10h MTBF=<1h Terms: Fault RepairFault Avoidance

3. 4.x Resilience Technology drivers -Increase of the number of errors, variety of errors. -Huge increase of components and threads, Power management, New hardware (Flash Mem., Accel., ) -Increase of the data size, limit of centralized I/O, higher potential bandwidth of local storage. Alternative R&D strategies -Fault recovery Fault avoidance (migration) -Transparent Application directed -Replication (backup core) Rollback Recovery (replicate locally and restart globally?) Recommended research agenda -Fault understanding (RAS analysis), modeling, prediction [S-M] -Fault isolation/confinement + local management [M] -Virtualization [S] -Extending the applicability of Rollback recovery (reducing ckpt size, caching, scalable FT protocols) [S] -Resilient Storage and file systems [S-L] -Resilience and programming/execution models (MW, Map Reduce, Transactions) [M-L] -Language / compiler support for resilience [M] -Resilient apps & algorithms (forward recovery, NFTA, ABFT) possibly with OS support [L] -Experimental environment to stress envisioned solutions [M] Crosscutting considerations -Resilience power management, performance (fault free situation and when faults occur) -scalability, programmability,