Andrew Noyes
9cafef8bbb
Some checks failed
Tests / Clang total: 932, passed: 932
Clang |Total|New|Outstanding|Fixed|Trend
|:-:|:-:|:-:|:-:|:-:
|0|0|0|0|:clap:
Tests / Release [gcc] total: 932, passed: 932
Tests / Release [gcc,aarch64] total: 931, failed: 309, passed: 622
Tests / Coverage total: 930, passed: 930
weaselab/conflict-set/pipeline/head There was a failure building this commit
105 lines
3.7 KiB
Markdown
105 lines
3.7 KiB
Markdown
A data structure for optimistic concurrency control on ranges of bitwise-lexicographically-ordered keys.
|
|
|
|
Intended to replace FoundationDB's skip list.
|
|
|
|
Hardware for all benchmarks is a mac m1 2020.
|
|
|
|
# FoundationDB's benchmark
|
|
|
|
## Skip list
|
|
|
|
```
|
|
New conflict set: 1.962 sec
|
|
0.637 Mtransactions/sec
|
|
2.549 Mkeys/sec
|
|
Detect only: 1.853 sec
|
|
0.674 Mtransactions/sec
|
|
2.698 Mkeys/sec
|
|
Skiplist only: 1.269 sec
|
|
0.985 Mtransactions/sec
|
|
3.940 Mkeys/sec
|
|
Performance counters:
|
|
Build: 0.0526
|
|
Add: 0.054
|
|
Detect: 1.85
|
|
D.Sort: 0.413
|
|
D.Combine: 0.0148
|
|
D.CheckRead: 0.678
|
|
D.CheckIntraBatch: 0.00679
|
|
D.MergeWrite: 0.591
|
|
D.RemoveBefore: 0.147
|
|
```
|
|
|
|
## Radix tree (this implementation)
|
|
|
|
```
|
|
New conflict set: 1.342 sec
|
|
0.931 Mtransactions/sec
|
|
3.726 Mkeys/sec
|
|
Detect only: 1.227 sec
|
|
1.018 Mtransactions/sec
|
|
4.074 Mkeys/sec
|
|
Skiplist only: 0.576 sec
|
|
2.169 Mtransactions/sec
|
|
8.676 Mkeys/sec
|
|
Performance counters:
|
|
Build: 0.0568
|
|
Add: 0.0564
|
|
Detect: 1.23
|
|
D.Sort: 0.414
|
|
D.Combine: 0.0162
|
|
D.CheckRead: 0.228
|
|
D.CheckIntraBatch: 0.00665
|
|
D.MergeWrite: 0.348
|
|
D.RemoveBefore: 0.211
|
|
```
|
|
|
|
# Our benchmark
|
|
|
|
## Skip list
|
|
|
|
| ns/op | op/s | err% | total | benchmark
|
|
|--------------------:|--------------------:|--------:|----------:|:----------
|
|
| 254.17 | 3,934,426.23 | 0.3% | 0.01 | `point reads`
|
|
| 275.58 | 3,628,769.92 | 2.1% | 0.01 | `prefix reads`
|
|
| 494.87 | 2,020,718.51 | 0.7% | 0.01 | `range reads`
|
|
| 495.91 | 2,016,512.61 | 1.7% | 0.01 | `point writes`
|
|
| 478.11 | 2,091,578.00 | 0.8% | 0.01 | `prefix writes`
|
|
| 307.08 | 3,256,480.40 | 1.9% | 0.04 | `range writes`
|
|
| 610.89 | 1,636,953.81 | 0.7% | 0.01 | `monotonic increasing point writes`
|
|
|
|
## Radix tree (this implementation)
|
|
|
|
| ns/op | op/s | err% | total | benchmark
|
|
|--------------------:|--------------------:|--------:|----------:|:----------
|
|
| 22.39 | 44,667,832.17 | 0.2% | 0.01 | `point reads`
|
|
| 53.89 | 18,554,840.41 | 3.4% | 0.01 | `prefix reads`
|
|
| 217.71 | 4,593,220.24 | 0.2% | 0.01 | `range reads`
|
|
| 29.72 | 33,642,099.66 | 1.1% | 0.01 | `point writes`
|
|
| 44.86 | 22,294,037.02 | 0.8% | 0.01 | `prefix writes`
|
|
| 55.00 | 18,181,818.18 | 0.8% | 0.03 | `range writes`
|
|
| 109.21 | 9,156,917.53 | 2.9% | 0.01 | `monotonic increasing point writes`
|
|
|
|
# "Real data" test
|
|
|
|
Point queries only, best of three runs. Gc ratio is the ratio of time spent doing garbage collection to time spent adding writes or doing garbage collection. Lower is better.
|
|
|
|
## skip list
|
|
|
|
```
|
|
Check: 11.7282 seconds, 318.763 MB/s, Add: 5.76499 seconds, 121.776 MB/s, Gc ratio: 48.0772%
|
|
```
|
|
|
|
## radix tree
|
|
|
|
```
|
|
Check: 3.27475 seconds, 1141.62 MB/s, Add: 2.13594 seconds, 328.678 MB/s, Gc ratio: 50.1739%
|
|
```
|
|
|
|
## hash table
|
|
|
|
(The hash table implementation doesn't work on range queries, and its purpose is to provide an idea of how fast point queries can be)
|
|
|
|
```
|
|
Check: 1.86291 seconds, 2006.81 MB/s, Add: 0.923653 seconds, 760.067 MB/s, Gc ratio: 54.2605%
|
|
``` |