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6005 :: Async web servers and database

• rufusroflpunch (orginal) [2020-02-28T14:49:51+01:00] view original

  Coming from other runtime environments with async support such as Python, one thing I have seen is that in order to take full advantage of async web servers, you need async database support. It doesn't seem in nim that the DB clients support async connections, which would lead me to believe that the async support is being underutilized. Am I correct in that, or is there something happening under the hood to make everything work as expected?

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• dom96 (orginal) [2020-03-01T12:30:43+01:00] view original

  Nope, you're correct. Someone needs to create an async mysql/sqlite/postgres etc. driver.

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• mrhdias (orginal) [2020-03-01T14:22:47+01:00] view original

  I find this repos for mysql and postgresql:

  https://github.com/wiml/nim-asyncmysql

  https://github.com/cheatfate/asyncpg

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• treeform (orginal) [2020-03-01T16:55:03+01:00] view original

  Also don't forget mine! https://github.com/treeform/pg

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• JohnAD (orginal) [2020-03-01T19:05:21+01:00] view original

  An alternative is to have a pooled driver that is friendly to async. My MongoDb driver does this: mongopool (on nimble).

  Essentially, the connections to the database are pooled and used dynamically by the server threads. So no slow down at scale.

  With postgresql and mysql this is not as pronounced as it is on MongoDb. On MongoDB an authenticated SCRAM connection can take 1 full second to form but the query is almost instantaneous. So having each thread start it's own connection is a very bad idea.

  I think some of the Python drivers do both: pooled connections and async.

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• rufusroflpunch (orginal) [2020-03-02T00:53:28+01:00] view original

  Treeform, that is great!

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• alexeypetrushin (orginal) [2021-05-16T19:39:19+02:00] view original

  I checked out the listed drivers:

  asyncpg has unfixed bugs and seems not supported.

  treeform/pg the pool waiting has await sleep_async(100) (https://github.com/treeform/pg/blob/master/src/pg.nim#L75) maybe it would be worth to reduce it to like 10 or 1? It's better to burn CPU than to waste time being idle...

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