Summary:
Looking for connected components in a random graph. This test performs the following:
- Generates a random graph that is NOT sequential in memory (otherwise itertion over edges is 2 or more times faster).
- Connectivity by iterating over all the edges.
- Ditto over vertices.
- Ditto over vertices in parallel.
Not done:
- Edge filtering based on XY. I could/should add that to see how it affects perf.
- Getting component info out from union-find.
Local results are encouraging. Iterating over the graph is the bottleneck. Still, I get connectivity of 10M vertices/edges in <7sec (parallel over vertices). Will test on 250M remote now.
Locally obtained results (20M/20M, 2 threads)
```
I1115 14:57:55.136875 357 otto_parallel.cpp:50] Generating 2000000 vertices...
I1115 14:58:19.057734 357 otto_parallel.cpp:74] Generated 2000000 vertices in 23.9208 seconds.
I1115 14:58:19.919221 357 otto_parallel.cpp:82] Generating 2000000 edges...
I1115 14:58:39.519951 357 otto_parallel.cpp:93] Generated 2000000 edges in 19.3398 seconds.
I1115 14:58:39.520349 357 otto_parallel.cpp:196] Running Edge iteration...
I1115 14:58:43.857264 357 otto_parallel.cpp:199] Done in 4.33691 seconds, result: 3999860270398
I1115 14:58:43.857316 357 otto_parallel.cpp:196] Running Vertex iteration...
I1115 14:58:49.498181 357 otto_parallel.cpp:199] Done in 5.64087 seconds, result: 4000090070787
I1115 14:58:49.498208 357 otto_parallel.cpp:196] Running Connected components - Edges...
I1115 14:58:54.232530 357 otto_parallel.cpp:199] Done in 4.73433 seconds, result: 323935
I1115 14:58:54.232570 357 otto_parallel.cpp:196] Running Connected components - Vertices...
I1115 14:59:00.412395 357 otto_parallel.cpp:199] Done in 6.17983 seconds, result: 323935
I1115 14:59:00.412422 357 otto_parallel.cpp:196] Running Parallel connected components - Vertices...
I1115 14:59:04.662087 357 otto_parallel.cpp:199] Done in 4.24967 seconds, result: 323935
I1115 14:59:04.662116 357 otto_parallel.cpp:196] Running Expansion...
I1115 14:59:13.913015 357 otto_parallel.cpp:199] Done in 9.25091 seconds, result: 323935
```
Reviewers: buda, mislav.bradac, dgleich, teon.banek
Reviewed By: buda, teon.banek
Subscribers: teon.banek, pullbot
Differential Revision: https://phabricator.memgraph.io/D982
968aa4926a