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  1. Percona Monitoring and Management
  2. PMM-9957

Postgresql Exporter Connections

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Details

    • Bug
    • Status: Done
    • Medium
    • Resolution: Fixed
    • 2.27.0
    • 2.31.0
    • Postgres_exporter
    • None
    • Yes
    • Yes
    • Yes

    Description

      Hello all,

       I am trying implement PMM across several postgres databases, and discovered that they were multiple connections instead of reusing as follows. Causing lots of log entries in postgres logs when connection log is enabled. 

       

      # Too many connection attempts
tcp        0      0 127.0.0.1:60430         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60102         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60720         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60814         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60592         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:59822         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60840         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:59916         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60032         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60478         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:59928         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60808         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60052         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60130         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60562         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:59906         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60776         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60818         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:56006         127.0.0.1:5432          ESTABLISHED
tcp        0      0 127.0.0.1:60248         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:59870         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60318         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60218         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60668         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:59868         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60506         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60624         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60320         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60186         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60696         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60164         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60658         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60678         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60376         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60788         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60216         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60650         127.0.0.1:5432          TIME_WAIT
tcp        0      0 127.0.0.1:60598         127.0.0.1:5432          TIME_WAIT

      And found out using autodiscover with unix socket does not properly connect to the DBs, dunno if it's possible to update the DATA_SOURCE_NAME manually. Or disabling it simply to avoid this.

      Which causes a lots of log entries in system journal (pmm-agent logs)

      May  1 03:32:05 meltdb01 pmm-agent[1648937]: #033[36mINFO#033[0m[2022-05-01T03:32:05.979+02:00] time="2022-05-01T03:32:05+02:00" level=info msg="Established new database connection to \"test1:5432\"." source="postgres_exporter.go:916"  #033[36magentID#033[0m=/agent_id/10c30cee-3c8b-4950-b0de-ff5541eb190d #033[36mcomponent#033[0m=agent-process #033[36mtype#033[0m=postgres_exporter
May  1 03:32:05 meltdb01 pmm-agent[1648937]: #033[36mINFO#033[0m[2022-05-01T03:32:05.979+02:00] time="2022-05-01T03:32:05+02:00" level=error msg="Error opening connection to database (postgres://pmm:[email protected]?connect_timeout=1&host=%!F(MISSING)var%!F(MISSING)run%!F(MISSING)postgresql&sslmode=disable): \"dial tcp: lookup test1 on [::1]:53: read udp [::1]:44429->[::1]:53: read: connection refused\": too many connection retries" source="postgres_exporter.go:1627"  #033[36magentID#033[0m=/agent_id/10c30cee-3c8b-4950-b0de-ff5541eb190d #033[36mcomponent#033[0m=agent-process #033[36mtype#033[0m=postgres_exporter
May  1 03:32:05 meltdb01 pmm-agent[1648937]: #033[36mINFO#033[0m[2022-05-01T03:32:05.979+02:00] time="2022-05-01T03:32:05+02:00" level=info msg="Established new database connection to \"test2:5432\"." source="postgres_exporter.go:916"  #033[36magentID#033[0m=/agent_id/10c30cee-3c8b-4950-b0de-ff5541eb190d #033[36mcomponent#033[0m=agent-process #033[36mtype#033[0m=postgres_exporter
May  1 03:32:05 meltdb01 pmm-agent[1648937]: #033[36mINFO#033[0m[2022-05-01T03:32:05.979+02:00] time="2022-05-01T03:32:05+02:00" level=error msg="Error opening connection to database (postgres://pmm:[email protected]?connect_timeout=1&host=%!F(MISSING)var%!F(MISSING)run%!F(MISSING)postgresql&sslmode=disable): \"dial tcp: lookup test2 on [::1]:53: read udp [::1]:46970->[::1]:53: read: connection refused\": too many connection retries" source="postgres_exporter.go:1627"  #033[36magentID#033[0m=/agent_id/10c30cee-3c8b-4950-b0de-ff5541eb190d #033[36mcomponent#033[0m=agent-process #033[36mtype#033[0m=postgres_exporter

       Also checked with the latest exporter from prometheus i do not see such behaviour when connecting to the DB connections remains stable. 1 connection per DB which seems ok.

      Seems this exporter is tad behind than upstream.

      Thanks a lot for this wonderful tool  

      Best Regards

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          relates to

          Improvement - An improvement or enhancement to an existing feature or task. PMM-7806 Upgrade postgres_exporter version used in pmm from 0.8.0 to 0.10.1

          • High - Crashes, loss of data, severe memory leak.
          • Done

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              Unassigned Unassigned
              rokat Mohamed
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