Incremental MapReduce Computations - Large Scale and Big Data: Processing and Management - page 136

(a) (b) (c) New map

output

Map
output

1 3 5 6 14

7 8 10 13 19 23

1 2 3 5 6 7 8 10 13 14 19

23

1-3-5 6-7 19-23

8-10-13-14

1-2-3-5 6-7 19-23

8-10-13-14

6-7-8-10-13-14

Contraction 6-7-8-10-13-14

6-7-8-10-13-14-19-23

Content-based marker
Mapper output
Combiner
Reducer

6-7-8-10-13-14-19-23

Reduce

Reduce

Reduce

FIGURE 4.4 Stability of the contraction phase. (a) First run. (b) Legend for (a) and (c). (c) Incremental run.