Idle desktop computers are already used for high performance computing. But there is a lack of wider use for parallel computing due to the limitations of the programming models available. We have built a new communication library that facilitates execution of parallel scientific applications on virtual clusters composed of volatile ordinary PC nodes.

1. INTER-TASK COMMUNICATION ON VOLATILE NODES Masters in Science (Computer Science) Thesis Presented by NAGARAJAN KANNA Advisor: Dr. Jaspal Subhlok Committee: Dr. Edgar Gabriel Dr. Margaret S. Cheung

10. COMMUNICATION MODEL Client machine running User application Dataspace Server (DSS) 1. Initialize application with DSS info 2. Establish connection with DSS 3. Put data (101, ABCD) 4. Read data (101) 5. Get data (101) 6. Terminate connection with DSS ABCD 101 DATA TAG DATA TAG

11. DATASPACE - ‘PUT’ Dataspace Server Client – Replica 1 Client – Replica 2 PUT Meta info from process 1 Tag & Data Status for PUT operation PUT Meta info from process 1 Status - SUCCESS DATA TAG PutCount ProcessId 1 1 PutCount ProcessId

12. DATASPACE - ‘READ’ and ‘GET’ Dataspace Server GET (Meta info & Tag) from process 1 Data matching the Tag from Dataspace GET (Meta info & Tag) from process 1 Corresponding Data Client – Replica 1 Client – Replica 2 ABCD 101 DATA TAG GetCount ProcessId 1 1 GetCount ProcessId DATA TAG 2 1 READ Buffer 2 ABCD 1 READ Buffer

20. PSRS 27 23 22 16 13 10

27. RTT: WITH 2 PROCESSES

28. BANDWIDTH: DATASPACE OPERATIONS

29. BANDWIDTH / HOP: WITH 2 PROCESSES

31. RTT: ‘READ’ WITH REPLICAS

32. RTT: ‘GET’ WITH REPLICAS

33. BANDWIDTH: ‘PUT’ WITH REPLICAS

34. BANDWIDTH: ‘READ’ WITH REPLICAS

35. BANDWIDTH: ‘GET’ WITH REPLICAS

36. SCALABILITY: PSRS

37. SCALABILITY: SoE

38. REDUNDANCY: PSRS

40. FAILURE: PSRS

46. THANK YOU