https://github.com/ppvan/master-slave-todos
https://github.com/ppvan/master-slave-todos
Last synced: 10 months ago
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- Host: GitHub
- URL: https://github.com/ppvan/master-slave-todos
- Owner: ppvan
- Created: 2024-06-15T16:49:48.000Z (almost 2 years ago)
- Default Branch: main
- Last Pushed: 2024-06-16T10:02:46.000Z (almost 2 years ago)
- Last Synced: 2024-06-16T20:49:18.684Z (almost 2 years ago)
- Language: Python
- Size: 554 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Load test with todos
This is a simple crud todos to try out some optimizations
Simple call create todos and get all todos (order by created at, limit 200).
Load test is perform by locust with read-write ratio: 6:4
Peak concurrent: 50
Users/second: 5
Connection pool: 25, overflow 5 (max 30)
## Getting started
Just run `docker compose up`. You 'll have api at [http://localhost:8000/](http://localhost:8000/)
and locust webui at [http://localhost:8089/](http://localhost:8089/).
> You might have to run migration.
> ```
> docker compose up migration -d
> ```
## Performance tuning
### Single database, no limit (get all todos in database)
#### No index
|Type|Name |Request Count|Failure Count|Median Response Time|Average Response Time|Min Response Time|Max Response Time|Average Content Size|Requests/s |Failures/s|50% |66% |75% |80% |90% |95% |98% |99% |99.9%|99.99%|100%|
|----|----------|-------------|-------------|--------------------|---------------------|-----------------|-----------------|--------------------|------------------|----------|----|----|----|----|----|----|----|----|-----|------|----|
|GET |/todos/ |1571 |0 |2400 |2335.308720560153 |12 |5598 |71875.68300445576 |13.091874600342026|0.0 |2400|3200|3600|3700|4100|4500|4800|5000|5500 |5600 |5600|
|POST|/todos/ |1064 |0 |1800 |1831.6475563909773 |20 |4349 |136.0 |8.866807495075694 |0.0 |1800|2500|2800|3000|3300|3600|3900|4100|4300 |4300 |4300|
| |Aggregated|2635 |0 |2100 |2131.9328273244782 |12 |5598 |42907.55294117647 |21.95868209541772 |0.0 |2100|2800|3300|3500|3900|4200|4700|4800|5500 |5600 |5600|
#### created_at index
```
CREATE INDEX idx_todomodel_created_at ON todos (created_at DESC);
```
|Type|Name |Request Count|Failure Count|Median Response Time|Average Response Time|Min Response Time|Max Response Time|Average Content Size|Requests/s |Failures/s|50% |66% |75% |80% |90% |95% |98% |99% |99.9%|99.99%|100%|
|----|----------|-------------|-------------|--------------------|---------------------|-----------------|-----------------|--------------------|------------------|----------|----|----|----|----|----|----|----|----|-----|------|----|
|GET |/todos/ |1578 |0 |2300 |2375.491761723701 |10 |5333 |72632.35994930292 |13.162817570236198|0.0 |2300|3200|3600|3900|4400|4700|5000|5100|5300 |5300 |5300|
|POST|/todos/ |1053 |0 |1800 |1819.1006647673314 |19 |4802 |136.0 |8.783553169492217 |0.0 |1800|2400|2700|3000|3500|3800|4000|4200|4300 |4800 |4800|
| |Aggregated|2631 |0 |2100 |2152.8084378563285 |10 |5333 |43617.2831622957 |21.946370739728415|0.0 |2100|2800|3300|3500|4100|4500|4800|5000|5300 |5300 |5300|
> It's really unexpect that postgresql will not use the index and just perform a seq scan, ? because most records(infact all of them) is fetch, so index does not make any diffirent here.
Also, index overhead is not a problem with a couple hundreds of records.
```sql
EXPLAIN SELECT * FROM todos ORDER BY created_at DESC;
QUERY PLAN
----------------------------------------------------------------
Sort (cost=145.88..148.56 rows=1075 width=48)
Sort Key: created_at DESC
-> Seq Scan on todos (cost=0.00..91.75 rows=1075 width=48)
(3 rows)
```
### 1 master, 1 slave, no limit (get all todos in database)
> Code base does take advantage of slave in read queries.
|Type|Name |Request Count|Failure Count|Median Response Time|Average Response Time|Min Response Time|Max Response Time|Average Content Size|Requests/s |Failures/s|50% |66% |75% |80% |90% |95% |98% |99% |99.9%|99.99%|100%|
|----|----------|-------------|-------------|--------------------|---------------------|-----------------|-----------------|--------------------|------------------|----------|----|----|----|----|----|----|----|----|-----|------|----|
|GET |/todos/ |1779 |0 |2300 |2086.167509836987 |10 |4997 |78399.50140528387 |14.850802609073337|0.0 |2300|2700|2900|3100|3600|4000|4400|4600|4900 |5000 |5000|
|POST|/todos/ |1194 |0 |1800 |1658.7303182579565 |19 |4133 |136.0 |9.967317771351077 |0.0 |1800|2100|2400|2500|2800|3100|3400|3700|4000 |4100 |4100|
| |Aggregated|2973 |0 |2000 |1914.502522704339 |10 |4997 |46967.74201143626 |24.818120380424414|0.0 |2000|2500|2700|2900|3300|3800|4200|4500|4800 |5000 |5000|
> At this point a try to improve code base performance instead of databse (queries are too simple)
#### Async handler
```py
@app.get("/todos/{id}", response_model=TodoRead, response_class=ORJSONResponse)
async def todo_index(id: int, db_session: Session = Depends(get_session)):
db_todo = db_session.query(TodoModel).filter(TodoModel.id == id).one()
return db_todo
```
|Type|Name |Request Count|Failure Count|Median Response Time|Average Response Time|Min Response Time|Max Response Time|Average Content Size|Requests/s |Failures/s|50% |66% |75% |80% |90% |95% |98% |99% |99.9%|99.99%|100% |
|----|----------|-------------|-------------|--------------------|---------------------|-----------------|-----------------|--------------------|------------------|----------|----|----|----|----|----|----|----|-----|-----|------|-----|
|GET |/todos/ |1980 |0 |1600 |1595.4757575757576 |7 |3591 |93617.87525252525 |16.509711939098867|0.0 |1600|2000|2300|2400|2800|3100|3300|3400 |3600 |3600 |3600 |
|POST|/todos/ |1385 |0 |1900 |1823.8519855595669 |19 |4819 |136.0 |11.548460119016127|0.0 |1900|2300|2600|2800|3300|3600|3900|4400 |4800 |4800 |4800 |
| |Aggregated|3365 |0 |1600 |1689.4731054977713 |7 |4819 |55141.67994056464 |28.058172058114994|0.0 |1600|2100|2400|2600|3000|3300|3700|3900 |4500 |4800 |4800 |
> Massive improvement by just using **async**, even more than replication?
#### Faster JSON encoding
Try to use [orjson](https://fastapi.tiangolo.com/advanced/custom-response/#orjsonresponse). Not good as I expected, maybe FastAPI baseline already fast enough?
|Type|Name |Request Count|Failure Count|Median Response Time|Average Response Time|Min Response Time|Max Response Time|Average Content Size|Requests/s |Failures/s|50% |66% |75% |80% |90% |95% |98% |99% |99.9%|99.99%|100% |
|----|----------|-------------|-------------|--------------------|---------------------|-----------------|-----------------|--------------------|------------------|----------|----|----|----|----|----|----|----|-----|-----|------|-----|
|GET |/todos/ |1976 |0 |1600 |1642.467105263158 |7 |3850 |92118.3886639676 |16.479856898212184|0.0 |1600|2100|2400|2600|2900|3100|3400|3500 |3800 |3800 |3800 |
|POST|/todos/ |1323 |0 |1900 |1853.148904006047 |18 |5490 |136.0 |11.033831313934574|0.0 |1900|2500|2800|2900|3300|3800|4000|4200 |5000 |5500 |5500 |
| |Aggregated|3299 |0 |1700 |1726.9569566535313 |7 |5490 |55230.63473779933 |27.513688212146757|0.0 |1700|2200|2500|2700|3100|3300|3800|3900 |4600 |5500 |5500 |
### 1 master, 1 slave, limit 200 (get 200 order by created_at DESC)
#### no index
|Type|Name |Request Count|Failure Count|Median Response Time|Average Response Time|Min Response Time|Max Response Time|Average Content Size|Requests/s |Failures/s|50%|66%|75%|80%|90% |95% |98% |99% |99.9%|99.99%|100%|
|----|----------|-------------|-------------|--------------------|---------------------|-----------------|-----------------|--------------------|------------------|----------|---|---|---|---|----|----|----|----|-----|------|----|
|GET |/todos/ |2137 |0 |860 |849.6686944314459 |64 |1730 |27601.0 |32.111475198311176|0.0 |860|910|950|980|1100|1300|1300|1300|1600 |1700 |1700|
|POST|/todos/ |1495 |0 |850 |842.1157190635452 |31 |1625 |137.0 |22.464508854223308|0.0 |850|900|950|980|1100|1300|1300|1400|1600 |1600 |1600|
| |Aggregated|3632 |0 |860 |846.5597466960353 |31 |1730 |16296.297356828194 |54.57598405253449 |0.0 |860|910|950|980|1100|1300|1300|1400|1600 |1700 |1700|
#### created_at index.
> With limit, now a index scan is performed which is much better than no index
```sql
EXPLAIN SELECT * FROM todos ORDER BY created_at DESC LIMIT 200;
QUERY PLAN
---------------------------------------------------------------------------------------------------
Limit (cost=0.29..4.07 rows=100 width=48)
-> Index Scan using idx_todomodel_created_at on todos (cost=0.29..426.02 rows=11249 width=48)
(2 rows)
```
|Type|Name |Request Count|Failure Count|Median Response Time|Average Response Time|Min Response Time|Max Response Time|Average Content Size|Requests/s |Failures/s|50%|66%|75%|80%|90% |95% |98% |99% |99.9%|99.99%|100%|
|----|----------|-------------|-------------|--------------------|---------------------|-----------------|-----------------|--------------------|------------------|----------|---|---|---|---|----|----|----|----|-----|------|----|
|GET |/todos/ |3642 |0 |770 |759.2468423942888 |52 |1563 |27601.0 |37.59474785086751 |0.0 |770|810|860|870|960 |1000|1100|1200|1200 |1600 |1600|
|POST|/todos/ |2384 |0 |760 |758.319211409396 |17 |1323 |137.0 |24.608972783214757|0.0 |760|810|850|870|960 |1000|1100|1200|1200 |1300 |1300|
| |Aggregated|6026 |0 |770 |758.8798539661467 |17 |1563 |16735.720212412878 |62.20372063408227 |0.0 |770|810|850|870|960 |1000|1100|1200|1200 |1600 |1600|