anschnapp
commented
8 months ago ok it seems like i had make a mistake. it seems like it was transaction independent but it was not.
with transactions also the mysql driver hangs, so i guess this issue is not inside the specific drivers but i don't know maybe in the spring r2dbc code...
do you know where to put this? of course this could be closed on your side if this is not an issue of the postgres driver
Bug Report
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Description
It seems like under some circumstances connections get stucked, we face a big issue because of this where our service gets unresponsable and almost unusable.
We are using r2dbbc with postgres and spring boot.
After a long time of debugging we still don't find the root cause but we could successfully reproduce it. Also we we're able to create a minimal reproduce example for this issue, you could review and try it out yourself here: https://github.com/anschnapp/r2dbc-issue-531-reproducer (their is also a mysql branch where you can see that this don't happen with other db drivers)
From our perspective multiple conditions have to be met to reproduce it:
Mono.fromFuture(writeAndReadOperation(round).toFuture())The last condition may appear to be a strange case. But there are some valid scenarios where such mono and future conversions are required.
We use it because of the usage of a caffeine cache which don't have a reactive api but a future based api. Also we guess that other sequences of reactive chains might have the same effect here, it's hard to say without knowing the real root cause for this.
We also think that this issue could be related to (https://github.com/pgjdbc/r2dbc-postgresql/issues/531) (that's why we had this ticket number in our example repo name). But our issue might be different it has quite many pre requirements. The other ticket seems to be much broader.
EDIT: It seems to be transaction specific (and not simple connections)