Connections leak in v0.14.0

[Monstrofil]

What did you do?

I've added postgres_exporter container to my application as following:

  postgres_exporter:
    image: quay.io/prometheuscommunity/postgres-exporter:v0.14.0
    restart: unless-stopped
    environment:
      DATA_SOURCE_NAME: "postgresql://...@postgres:5432/...?sslmode=disable"
    ports:
      - 9187:9187

What did you expect to see?

I expected postgres_exporter to use only couple of connections with postgresql to grab statistics.

What did you see instead? Under which circumstances?

I see postgres_exporter contantly using more and more connections with each scrape.

Steps to reproduce

• setup postgres and postgres_exporter containers
• run ab -n 1000 -c 2 http://host:9187/metrics to speed up things a little
• check pg_stat_database_numbackends metric, it will keep growing until reaches max_connections

We don't have this issue with v0.13.0, but we do have it with v0.14.0 and latest tags.

[SuperQ]

Duplicate of #921

[SK-000]

Connections leak in v0.14.0

Do we have any bug fix for this postgres exporter connection leaks ?