Same error..distro: Antergos Gnome, Erlang 20.3.7 and Elixir 1.6.5
Green4ao
miha
same error here, but only on a production server. Running Arch Linux on both dev and prod machines.
Erlang 20.3.8, Elixir 1.6.5. postgresq db has only four tables with a maximum of 10 rows.
The main question is, how to debug this in production to find the source of the error.
1
amagdas
This looks to be fixed by Erlang: Timeouts on Poolboy.checkout · Issue #127 · elixir-ecto/db_connection · GitHub
5
axelson
Scenic Core Team
@amagdas Thanks for updating this thread!
This was all fascinating reading:
- Elixir bug report with initial investigation: Timeouts on Poolboy.checkout · Issue #127 · elixir-ecto/db_connection · GitHub
- Erlang bug report with c/assembly-level investigation: Redirecting…
- The patch that fixes the issue: Fix a race condition when generating async operation ids · jhogberg/otp@e27b98b · GitHub
A high-level summary is that erlang ports updated a shared global counter async_ref in a way that was not atomic. This race-condition has existed for quite a while but on pre GCC 8.1 this variable would only get read once in each thread. But GCC 8.1 (especially with some optimizations enabled) exposed the race-condition and caused prim_inet:recv0/3 to hang because it was waiting for the wrong reference (since it was waiting for a reference from a different thread). The bug was fixed by changing the async_ref to be unique per-port (since it doesn’t actually need to be shared between ports). This fix is included in Erlang/OTP 21.0.2.
If I got any of that wrong please feel free to correct it 
3