Steps to recreate

• docker-compose up -d
• docker exec -it postgres /bin/bash
• psql -U postgres-user customers
• Execute SQL in customer-setup.sql
• select usename, datname, application_name, state from pg_stat_activity;
  • no connections corresponding to PostgreSQL JDBC Driver
• In another terminal window, execute:

      curl --location --request POST 'localhost:28083/connectors' \
      --header 'Content-Type: application/json' \
      --data-raw '{
          "name": "customers.source.connector",
          "config": {
              "connector.class": "io.debezium.connector.postgresql.PostgresConnector",
              "plugin.name": "pgoutput",
              "database.server.name": "customers",
              "database.password": "postgres-pw",
              "database.port": "5432",
              "database.hostname": "postgres",
              "database.user": "postgres-user",
              "database.dbname": "customers",
              "slot.name": "customers",
              "table.include.list": "public.customers"
          }
      }'
  

• in psql window, execute: select usename, datname, application_name, state from pg_stat_activity; again
  • expected: 2 PostgreSQL JDBC Driver connections
  • actual: 4 PostgreSQL JDBC Driver connections (3 of which are idle)

Note if we use the default decoderbufs plugin instead of pgoutput, there are 3 PostgreSQL JDBC Driver connections