1. Recovery Oriented Computing: Update Armando Fox (in loco Patterson) Summer ROC Retreat, June 2002

2. © 2002 Armando Fox Welcome and ROC Philosophy n ROC philosophy (“Peres’s Law”): “If a problem has no solution, it may not be a problem, but a fact; not to be solved, but to be coped with over time” Israeli foreign minister Shimon Peres l Failures (hardware, software, operator-induced) are a fact; recovery is how we cope with them over time l Availability = MTTF/MTBF= MTTF / (MTTF + MTTR) - rather than just making MTTF very large, make MTTR << MTTF n ROC Principles 1. Isolation and partitionability => redundancy 2. Enable fault injection, output checking => online monitoring & verification 3. Undo support 4. Diagnostic support

3. © 2002 Armando Fox Major ROC Areas n Failure detection and diagnosis l Pinpoint l FIG l Internet service failure causes n Recovery techniques and Design-for-Recovery l Recursive Restartability l Making state-management tradeoffs explicit (QAPSL) l Firm state from infirm components (RAINS) l Designing for Undo: theory and practice n Benchmarking and measurement l Dependability benchmarks for various applications l End-user availability measurements on the Web l Why Internet services fail l Estimating the cost of downtime l Availability in the PSTN

4. © 2002 Armando Fox Recent Publications ROC Techniques and Tools: n A Utility-Centered Approach to Internet Services Design. George Candea, Armando Fox, in SIGOPS European Workshop n FIG: A prototype Tool for Online Verification of Recovery Mechanisms. P. Broadwell, N.Sastry, J.Traupman, D.Patterson, in SHAMAN workshop at ICS 2002 n Rewind, repair, replay: 3 R’s to Dependability. A. Brown and D. Patterson, SIGOPS European Workshop n Including the Human Factor in Dependability Benchmarks. A. Brown, L. Chung, D. Patterson. In DSN 2002 Workshop on Dependability Benchmarking. ROC Measurements: n Architecture, operation, and dependability of large-scale Internet services: three case studies. D. Oppenheimer and D.A. Patterson. Submission to IEEE Internet Computing special issue on Global Deployment of Data Centers, February 2002. (Shorter version in SIGOPS European Workshop) n Measuring End-User Availability on the Web: Practical Experience. Matthew Merzbacher and Dan Patterson. n Lessons from the PSTN for Dependable Computing. P.Enriquez, A.Brown, D.Patterson, in SHAMAN workshop at ICS 2002. Fault monitoring/diagnosis: n An Online Evolutionary Approach to Internet Services. E. Kiciman, M. Chen, E. Brewer. In SIGOPS European Workshop

5. © 2002 Armando Fox Recent Evangelism n Evangelism publications l “Case for ROC” Technical Report l Introduction to Dependability (;login) l A Simple Way to Measure Cost of Downtime (LISA 02) n Evangelism talks l Microsoft Research l HPCA 02 keynote (Patterson) l FAST keynote (Filesystems And Storage Technologies) l IBM Autonomic Computing workshops (Almaden & TJ Watson)

6. © 2002 Armando Fox About ROC Retreats n Purpose of semi-annual retreats l Progress reports/talks from academia and industry l Exposure/feedback on new ideas or work in progress l Brainstorming in immersive atmosphere l Industry/visitor feedback, opportunities for collaboration l Water fights during rafting trip n Logistics l Web server with retreat talks/papers - thanks to Mike Howard and Bob Miller - http://172.16.10.43/roc, WaveLAN “ANY”

7. © 2002 Armando Fox Retreat Schedule - a work in progress n Rest of today l OceanStore update from Kubi l Intros l ROC talks l All day: Posters (especially right before & after dinner) n Tomorrow l Morning: OceanStore talks l Afternoon: Lunch and rafting l Post-rafting: breakout sessions followed by dinner l Breakout reporting/joint panel session with SAHARA n Wednesday l Industry talk(s) l “Open mike”/outrageous ideas session? l Visitor feedback

8. © 2002 Armando Fox Breakout Sessions n Target: 3-4 breakouts l Using virtual machine technology for ROC l Ideas for the second ROC showcase application l Applying ROC to OceanStore l Management and Self-healing of large-scale systems l Is >100 year storage a pipe dream? n Other topics solicited n Final breakout topics will be decided based on interest in each topic and limiting each group size