I've added locust.io config file to the server and performed "extreme" load test. (i.e. I've used "extreme" load times of git.sr.ht/~qeef/damn-server/tr)

Outcomes are: (1) python server just waits for the database (and it should be like that), (2) about 1 GB RAM is sufficient, (3) need to work on SELECT queries.

Query type: Average / Percentile(99)
INSERT: 2 ms / 634 ms
SELECT: 32 ms / 57 s 834 ms

Next is "average" load test run overnight.

Overnight test failed (too many 404: no square to map -- that's not an error, but I don't want to test it.) So, I run the average test (each mapper map for 30 - 60 s, then wait for 30 - 60 s before next mapping) again for 3 hours.

For the database queries:
Max duration / Latency Percentile(99)
1 s 190 ms / 32 s 502 ms

From the locust.io testing: 31582 POST requests (the real work) with 99%ile of 420 ms!

2 uvicorn workers, 4 GB RAM, Intel i5-2520M @ 2.5 GHz. Locust.io runs on the same machine.

damn-project.org/ runs the project on $5/month do.co instance with 1 GB RAM, single 2.2 GHz vCPU, and 25 GB SSD disk. Why not to load test it?

I run the locust.io load testing for


with 100 mappers (all spawned in the first minute,) and "average" load scenario: 30 - 60 s mapping, 30 - 60 s waiting (git.sr.ht/~qeef/damn-server/tr).

After 3 hours, the statistics of the areas were (to map, to review, done:) 0%/31%/69%, respective 0%/55%/45%.

I had to stop the load test of


with 200 mappers after approximately 20 minutes. (The test performed since 17:00 till 17:30.) The statistics of the areas when stopped were (to map, to review, done:) 9%/66%/25%, respective 37%/47%/16%.

The reason to stop the test was increase in the resource utilization. Unfortunately, I have no database logs this time.

I did some improvements to the server and the database. Testing on the localhost looks good. Next, I need to test the server of the damn-project.org/ instance.

(The images are from the "extreme" scenario of load testing git.sr.ht/~qeef/damn-server/tr run for few minutes only.)

deploy v0.20.0 git.sr.ht/~qeef/damn-deploy/re includes the improvements.

The results of load testing for the server of damn-project.org/ with 4 areas and 200 mappers (all spawned in the first minute,) and "average" load scenario: 30 - 60 s mapping, 30 - 60 s waiting (git.sr.ht/~qeef/damn-server/tr) are attached.

Run for 1.5 hour approximately -- after that time there were 0 % to map for all of the areas so the results could become biased.

Server: 1x 2.2 GHz vCPU, 1 GB RAM, 25 GB SSD.

I think that 200 mappers (30 s mapping, 30 s waiting) with 4 areas is the top wall for load testing. I've tested 300 mappers with 6 areas for about 10 minutes and I don't feel confident about it.

Recall that the instance of damn-project.org/ runs on $5/month VPS with 1x 2.2 GHz vCPU, 1 GB RAM, and 25 GB SSD.

First round of endurance load testing. Started at 12:00, 0% to map at 15:00, non-recoverable CPU load after 18:00.

My guess is that it's upkeep scripts.

Also, I think that I should speed up waiting of locust average mappers from 30 - 60 seconds to 2 - 5 seconds. I will let the mapping time of 30 - 60 seconds, though.

Let's see.

So the results looks more like the "extreme" results when changing times towards the "extreme" load times (git.sr.ht/~qeef/damn-server/tr) I will keep "extreme" and "average"clearly distinguished.

What also influence the results is locust _spawn rate_ (mappers spawned/second) I will keep it such that all the mappers are spawned within the first minute.

Also, actual database parameters are git.sr.ht/~qeef/damn-deploy/co


I did another round of "average" load testing for 200 mappers and 2 areas to maintain the compatibility with en.osm.town/web/statuses/10618 and en.osm.town/web/statuses/10618 (the same number of mappers, the same number of areas.)

The interesting time is at start 11:40 -- spawning of mappers. Next, around 12:13 to 12:18, where mapping is finished (i.e. 0 % to map). Finally, 12:45 -- upkeep script runs while server is returning 404: no square to map. (I checked it with `journalctl -u damn_upkeep.service -f`.)

This is forgotten I/O utilization graph for the last "average" test of 200 mappers and 2 areas.

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