I have configured a PostgreSQL CDC Connector in Confluent, which is connected to an AWS RDS instance.
The messages from each table are being streamed into the topics but the structure for the JSON is
However, I was expecting something like this structure according to the docs (specifically with the before, after, and op fields)
I have tried setting the REPLICA IDENTITY to FULL, according to the docs, but it's still not working.
Any idea how I can get these fields?
Figured out I was missing setting the after-state only parameter in Advanced Configuration to false.
Related
I have successfully set up Kafka Connect in distributed mode locally with the Confluent BigQuery connector. The topics are being made available to me by another party; I am simply moving these topics into my Kafka Connect on my local machine, and then to the sink connector (and thus into BigQuery).
Because of the topics being created by someone else, the schema registry is also being managed by them. So in my config, I set "schema.registry.url":https://url-to-schema-registry, but we have multiple topics which all use the same schema entry, which is located at, let's say, https://url-to-schema-registry/subjects/generic-entry-value/versions/1.
What is happening, however, is that Connect is looking for the schema entry based on the topic name. So let's say my topic is my-topic. Connect is looking for the entry at this URL: https://url-to-schema-registry/subjects/my-topic-value/versions/1. But instead, I want to use the entry located at https://url-to-schema-registry/subjects/generic-entry-value/versions/1, and I want to do so for any and all topics.
How can I make this change? I have tried looking at this doc: https://docs.confluent.io/platform/current/schema-registry/serdes-develop/index.html#configuration-details as well as this class: https://github.com/confluentinc/schema-registry/blob/master/schema-serializer/src/main/java/io/confluent/kafka/serializers/subject/TopicRecordNameStrategy.java
but this looks to be a config parameter for the schema registry itself (which I have no control over), not the sink connector. Unless I'm not configuring something correctly.
Is there a way for me to configure my sink connector to look for a specified schema entry like generic-entry-value/versions/..., instead of the default format topic-name-value/versions/...?
The strategy is configurable at the connector level.
e.g.
value.converter.value.subject.name.strategy=...
There are only strategies built-in, however for Topic and/or RecordName lookups. You'll need to write your own class for static lookups from "generic-entry" if you otherwise cannot copy this "generic-entry-value" schema into new subjects
e.g
# get output of this to a file
curl ... https://url-to-schema-registry/subjects/generic-entry-value/versions/1/schema
# upload it again where "new-entry" is the name of the other topic
curl -XPOST -d #schema.json https://url-to-schema-registry/subjects/new-entry-value/versions
I am looking to write a custom connector for Apache Kafka to connect to SQL database to get CDC data. I would like to write a custom connector so I can connect to multiple databases using one connector because all the marketplace connectors only offer one database per connector.
First question: Is it possible to connect to multiple databases using one custom connector? Also, in that custom connector, can I define which topics the data should go to?
Second question: Can I write a custom connector in .NET or it has to be Java? Is there an example that I can look at for custom connector for CDC for a database in .net?
There are no .NET examples. The Kafka Connect API is Java only, and not specific to Confluent.
Source is here - https://github.com/apache/kafka/tree/trunk/connect
Dependency here - https://search.maven.org/artifact/org.apache.kafka/connect-api
looking to write a custom connector ... to connect to SQL database to get CDC data
You could extend or contribute to Debezium, if you really wanted this feature.
connect to multiple databases using one custom connector
If you mean database servers, then not really, no. Your URL would have to be unique per connector task, and there isn't an API to map a task number to a config value. If you mean one server, and multiple database schemas, then I also don't think that is really possible to properly "distribute" within a single connector with multiple tasks (thus why database.names config in Debezium only currently supports one name).
explored debezium but it won't work for us because we have microservices architecture and we have more than 1000 databases for many clients and debezium creates one topic for each table which means it is going to be a massive architecture
Kafka can handle thousands of topics fine. If you run the connector processes in Kubernetes, as an example, then they're centrally deployable, scalable, and configurable from there.
However, I still have concerns over you needing all databases to capture CDC events.
Was also previously suggested to use Maxwell
The aim that I want to achieve:
is to be notified about DB data updates, for this reason, I want to build the following chain: PostgreSQL -> Kinesis -> Lambda.
But I am now sure how to notify Kisesis properly about DB changes?
I saw a few examples where peoples try to use Postgresql triggers to send data to Kinesis.
some people use wal2json concept.
So I have some doubts about which option to choose, that why I am looking for advice.
You can leverage Debezium to do the same.
Debezium connectors can also be intergrated within the code, using Debezium Engine and you can add transformation or filtering logic(if you need) before pushing the changes out to Kinesis.
Here's a link that explains about Debezium Postgres Connector.
Debezium Server( Internally I believe it makes use of Debezium Engine).
It supports Kinesis, Google PubSub, Apache Pulsar as of now for CDC from Databases that Debezium Supports.
Here is an article that you can refer to for step by step configuration of Debezium Server
[https://xyzcoder.github.io/2021/02/19/cdc-using-debezium-server-mysql-kinesis.html][1]
I've added the following line to my server.properties file:
confluent.support.metrics.enable=false
However, when KSQL starts up, it spits out the following:
Please note that the version check feature of KSQL is enabled.
...
By proceeding with `confluent.support.metrics.enable=true`, you agree to
all such collection, transfer and use of Version information by Confluent.
You can turn the version check feature off by setting
`confluent.support.metrics.enable=false` in the KSQL configuration and
restarting the KSQL. See the Confluent Platform documentation for further information.
I know this properties file is being read and parsed by KSQL because it's pulling the other configs (like broker info) and reading that just fine. It's basically just ignoring my request to turn off metric collection. Any idea on how to actually turn this off?
This appears to have been a bug in KSQL. It was fixed here:
https://github.com/confluentinc/ksql/pull/2948
I am trying to use kafka connect to read changes in postgress DB.
I have Kafka running on my local system and i want to use the Kafka connect API in standalone mode to read the postgress server DB changes.
connect-standalone.sh connect-standalone.properties dbezium.properties
i would appreciate if someone can help me with setting up configuration properties for CDC postgress debezium connector
https://www.confluent.io/connector/debezium-postgresql-cdc-connector/
I am following the below to construct the properties
https://debezium.io/docs/connectors/postgresql/#how-the-postgresql-connector-works
The name of the Kafka topics takes by default the form
serverName.schemaName.tableName, where serverName is the logical name
of the connector as specified with the database.server.name
configuration property
and here is what i have come up with for dbezium.properties
name=cdc_demo
connector.class=io.debezium.connector.postgresql.PostgresConnector
tasks.max=1
plugin.name=wal2json
slot.name=debezium
slot.drop_on_stop=false
database.hostname=localhost
database.port=5432
database.user=postgress
database.password=postgress
database.dbname=test
time.precision.mode=adaptive
database.sslmode=disable
Lets say i create a PG schema name as demo and table name as suppliers
So i need to create a topic with name as test.demo.suppliers so that this plugin can push the data to?
Also can someone suggest a docker image which has the postgress server + with suitable replication plugin such as wal2json etc? i am having hard time configuring postgress and the CDC plugin myself.
Check out the tutorial with associated Docker Compose and sample config.
The topic you've come up with sounds correct, but if you have your Kafka broker configured to auto-create topics (which is the default behaviour IIRC) then it will get created for you and you don't need to pre-create it.