Hello, we have a weird case with connection poolin...
# orm-helpj
Julien Goux
03/16/2022, 3:39 PMHello, we have a weird case with connection pooling and interactive transactions. We have a pool size of max 3 connections. We open an interactive transaction and also execute queries that aren’t bound to this transaction at the same time
Julien Goux
03/16/2022, 3:39 PMThe issue is that prisma doesn’t create other connections to the database while our interactive transaction is running
Julien Goux
03/16/2022, 3:39 PMIt get stuck to 1 connection and eventually the transaction throws a timeout error
Julien Goux
03/16/2022, 3:40 PMbecause the other queries are awaited inside the transaction, so the transaction is stuck as prisma isn’t creating one more connection
Julien Goux
03/16/2022, 3:56 PMIs there any issue about prisma being unable to create new connections even if we didn’t reach the max connection limit in the pool?
d
dpetrick
03/16/2022, 4:09 PMAn interactive transaction (itx) completely removes one connection from the pool until that itx finishes in some form. You'd have to elaborate on the "gets stuck on 1 connection" part, because the pool should have two other connections to work with to execute non-itx queries coming in.
j
Julien Goux
03/16/2022, 4:10 PM@dpetrick This is our issue, the pool has only one connection, even if we set 3 max connection as parameter
Julien Goux
03/16/2022, 4:11 PMSo it seems that at some point either prisma lose those 2 connections and can’t / doesn’t know it has to create them back, or it never created them from the start
Julien Goux
03/16/2022, 4:12 PMwe don’t have the issue in all of our environments but when it happens we have CI failures 😛
Julien Goux
03/16/2022, 4:12 PMI don’t know how to investigate this issue further
d
dpetrick
03/16/2022, 4:16 PMI'm not 100% sure if related, but we're currently investigating pooling issues and will release a fix for a deadlocked pool soon.
To be clear: First thing you do when you connect to prisma is open an itx, then try to run more queries? That will lead to no more connections being opened?
j
Julien Goux
03/17/2022, 8:20 AM@dpetrick The main issue is isn’t really transaction related, it’s that prisma is stuck at 1 connection in the pool, it doesn’t create new connections (it could create up to 3)
Julien Goux
03/17/2022, 8:20 AMWe restarted our container hosting our prisma code and made several tests but couldn’t reproduce so far
Julien Goux
03/17/2022, 8:21 AMLike killing all the connections postgres’ side, next http request prisma is recreating 3 connections as expected. Killing 2 out of 3 connections, next http request prisma is recreating 2 connections as expected.
Julien Goux
03/17/2022, 8:22 AMBut as some point something is happening in some of our PR and prisma is stuck at a fixed number of connections and can’t create new ones.
d
dpetrick
03/17/2022, 11:46 AMThat sounds related to our current pooling investigation then. We already have a fix ready to ship in the next release for that, which hopefully solves your issues too. I can also offer to notify you when you can use a dev build to test this sooner than release.
j
Julien Goux
03/18/2022, 3:20 PMGreat news, thanks for all the answers @dpetrick!
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