Is there any way to use MongoSourceConnector for multiple database with single kafka topic? - mongodb

Question

I am using MongoSourceConnector to connect kafka topic with mongo database collection. For single database with single kafka topic it's working fine, but is there any way that i could do a connection for multiple mongo database with single kafka topic.

Answer 1

If you are running kafka-connect in distributed mode then you can create a another connector config file with the above mentioned config

Answer 2

I am not really sure about multiple databases and a single Kafka topic but you can surely listen to multiple databases change streams and push data to topics. Since topic creation depends on the database_name.collection_name, so you will have more topics.
You can provide the Regex to listen to multiple databases in the pipeline.
"pipeline": "[{\"$match\":{\"$and\":[{\"ns.db\":{\"$regex\":/^database-names_.*/}},{\"ns.coll\":{\"$regex\":/^collection_name$/}}]}}]"
Here is the complete Kafka connector configuration.
Mongo to Kafka source connector
{
"name": "mongo-to-kafka-connect",
"config": {
"connector.class": "com.mongodb.kafka.connect.MongoSourceConnector",
"publish.full.document.only": "true",
"tasks.max": "3",
"key.converter.schemas.enable": "false",
"topic.creation.enable": "true",
"poll.await.time.ms": 1000,
"poll.max.batch.size": 100,
"topic.prefix": "any prefix for topic name",
"output.json.formatter": "com.mongodb.kafka.connect.source.json.formatter.SimplifiedJson",
"connection.uri": "mongodb://<username>:<password>#ip:27017,ip:27017,ip:27017,ip:27017/?authSource=admin&replicaSet=xyz&tls=true",
"value.converter.schemas.enable": "false",
"copy.existing": "true",
"topic.creation.default.replication.factor": 3,
"topic.creation.default.partitions": 3,
"topic.creation.compacted.cleanup.policy": "compact",
"value.converter": "org.apache.kafka.connect.storage.StringConverter",
"key.converter": "org.apache.kafka.connect.storage.StringConverter",
"mongo.errors.log.enable": "true",
"heartbeat.interval.ms": 10000,
"pipeline": "[{\"$match\":{\"$and\":[{\"ns.db\":{\"$regex\":/^database-names_.*/}},{\"ns.coll\":{\"$regex\":/^collection_name$/}}]}}]"
}
}
You can get more details from official docs.
https://www.mongodb.com/docs/kafka-connector/current/source-connector/
https://docs.confluent.io/platform/current/connect/index.html