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Connection pool exceeds maximum

See original GitHub issue

Steps to reproduce

No idea unfortunately - this is an intermittent issue.

The issue

Web API connects to Postgres DB using Npgsql. This application performs a simple DB read operation of a few thousand rows which usually takes ~250ms
Very occasionally, the application hangs while awaiting the asynchronous DB read. I’ve seen this hang for up to 300s - despite this delay, the call does complete successfully and the API returns HTTP 200
Connection pool is limited to a maximum of 6 in the connection string
I’ve observed 7 connections from a single client from looking at pg_stat_activity. It seems like this coincides with the issue described above - when the application hangs on a DB read, the connection pool maximum has been exceeded

Further technical details

Npgsql version: 4.0.10 PostgreSQL version: PostgreSQL 9.6.15, compiled by Visual C++ build 1800, 64-bit Operating system: web API is running inside Docker container, running Debian GNU/Linux 9. Postgres DB is Azure managed database

Any idea what’s going on here?

Issue Analytics

State:
Created 4 years ago
Comments:10 (5 by maintainers)

Top GitHub Comments

2reactions

21robin12commented, Dec 15, 2019

Since upgrading we haven’t seen this issue, so I’m hoping it’s fixed. Not 100% sure since it was such an intermittent problem, sometimes a couple of weeks between occurrences.

0reactions

21robin12commented, Jan 21, 2020

We haven’t seen this issue since upgrading 2 months ago (21st November) so I’m fairly confident this is resolved. Thanks for your help @roji @NinoFloris

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