1. Mizan:Graph Processing System xuejilong@gmail.com

2. topics Brief introduction on Pregel EuroSys'13 paper: Mizan Our ideas

3. Pregel A System for Large-Scale Graph Processing Mapreduce v.s. Pregel Hadoop v.s. Hama,Giraph...

4. Inside Pregel Graph partitioning Graph data Worker1 Worker2 Workern … Pregel output Communication cost Load balance

5. Inside Pregel

6. Problems of Pregel Worker1 Worker2 Workern Worker1 Worker2 Workern …… Computation Communication

7. Mizan A system for Dynamic Load Balancing in Large-scale Graph Processing

8. Load balance Current method for load balance: –Hash partition, Giraph, Pregel –Range partition, –Min-cut partition(Metis) –Sophisticated partitioning tech.

9. Mizan goal building a system that is: –Adaptive –Agnostic to the graph structure –requires no a priori knowledge of algorithm behavior

10. Graph algorithms –Stationary Graph Algorithms: matrix-vector multiplication PageRank finding weakly connected components –Non-stationary Graph Algorithms: DMST: distributed minimal spanning tree graph queries advertisement propagation

11. Mizan Monitoring Migration planning

12. Monitoring 1.Outgoing message 2.Incoming message 3.Response time

13. Migration Planning Five-step migration planning: –Identify the source of imbalance –Select the migration objective –Pair over-utilized workers with under-utilized ones –Select vertices to migrate –Migrate vertices

14. Step 1

15. Step 2 Select the migration objective –Outgoing msg, incoming msg, response time –Compute correlation between: Outgoing msg and response time Incoming msg and response time Default response time

16. Step 3

17. Step 4

18. Step 5 Migrate vertices –when all workers arriving at migration barrier –Migrated data: vertex ID State edge information (friends list) the received messages it will process

19. Mizan

20. Mizan implementation

21. Challenge 1: Vertex Ownership –huge data –Frequent vertex migration Techs: –Each vertex has a home_worker –HDT maintain home_worker location

22. Mizan implementation Challenge 2: Large Message Size

23. Evaluation Experiments: –Implemented Mizan using C++ and MPI –12 machines with i5 processor 16GB RAM

24. Evaluation Benchmarks: –Static: disables any dynamic migration –Work Stealing (WS): Pregel version –Mizan.

25. Evaluation Static Mizan vs. Giraph:

26. Evaluation PageRank on three system:

27. Evaluation Migration costs:

28. Evaluation Un-stationary algorithm:

29. Evaluation Migration overhead:

30. Really? Some arguable parts of Mizan: –Cost: migration planning, multi global information synchronization(S1,S2,S3) Especially in S3, global order maintaining –Large data transferred in migration –Migration will lead more cross-communication –Centralized management bad than decentralized? –Not friendly to graph mutation ……