Error "The 'topic.prefix' value is invalid" for Outbox Event Router configuration

[Stanislav Karmanov]

Hello! I'm using Debezium 2.5 (in docker) and I encountered a problem with the Postgres connector configuration. Here is my connector config

{
"name": "user-profiles-pg-connector",
"config": {
"connector.class": "io.debezium.connector.postgresql.PostgresConnector",
"database.hostname": "mb-postgres.docker",
"database.port": "5432",
"database.user": "root",
"database.password": "root",
"database.dbname": "profiles",
"schema.include.list": "public",
"table.include.list": "public.OUTBOX",
"plugin.name": "pgoutput",

"value.converter": "org.apache.kafka.connect.json.JsonConverter",
"transforms": "outbox",
"transforms.outbox.type": "io.debezium.transforms.outbox.EventRouter",
"transforms.outbox.table.expand.json.payload": true,
"transforms.outbox.route.by.field": "channel",
"transforms.outbox.route.topic.replacement": "${routedByValue}",
"transforms.outbox.table.fields.additional.placement": "type:header",
"transforms.outbox.table.field.event.key": "key",
"transforms.outbox.table.field.event.timestamp": "timestamp"
}
}

and docker compose file

version: "3.9"

services:
postgres:
image: postgres:16.1
restart: "no"
environment:
PGDATA: /var/lib/postgresql/data/pgdata
POSTGRES_MULTIPLE_DATABASES: profiles,auth
POSTGRES_USER: root
POSTGRES_PASSWORD: root
container_name: mb_postgres
command: ["postgres", "-c", "wal_level=logical"]
ports:
- "5432:5432"
volumes:
- ./volumes/db:/var/lib/postgresql/data/pgdata
- ./config/db:/docker-entrypoint-initdb.d
networks:
mb:
aliases:
- mb-postgres.docker

zookeeper:
image: bitnami/zookeeper:3.7.2
volumes:
- ./volumes/zookeeper:/bitnami/zookeeper
environment:
- ALLOW_ANONYMOUS_LOGIN=yes
networks:
mb:
aliases:
- zookeeper.docker

kafka:
image: bitnami/kafka:3.4.1
environment:
- KAFKA_CFG_ZOOKEEPER_CONNECT=zookeeper.docker:2181
depends_on:
- zookeeper
volumes:
- ./volumes/kafka:/bitnami/kafka
networks:
mb:
aliases:
- kafka.docker

connect:
image: debezium/connect:2.5
ports:
- "8083:8083"
environment:
- BOOTSTRAP_SERVERS=kafka.docker:9092
- GROUP_ID=1
- CONFIG_STORAGE_TOPIC=config
- OFFSET_STORAGE_TOPIC=offset
- STATUS_STORAGE_TOPIC=status
- ENABLE_DEBEZIUM_SCRIPTING=true
depends_on:
- kafka
- postgres
networks:
mb:
aliases:
- connect.docker

kafdrop:
image: obsidiandynamics/kafdrop:4.0.1
ports:
- "9000:9000"
environment:
- KAFKA_BROKERCONNECT=kafka.docker:9092
depends_on:
- kafka
networks:
mb:
aliases:
- kafdrop.docker

networks:
mb:

When I add the connector above I get the error "The 'topic.prefix' value is invalid". But event if 'topic.prefix' is added nothing happens. Everything goes fine without Outbox Event Router configuration. What am I doing wrong? Thank you in advance.

[jiri.p...@gmail.com]

Hi,

are you sure you set it properly? It is this option https://debezium.io/documentation/reference/2.5/connectors/postgresql.html#postgresql-property-topic-prefix

J.