Debezium : Data deleted from MySQL reappearing in Elasticsearch - elasticsearch

Question

I've used Debezium for Mysql -> Elasticsearch CDC.
Now, the issue is that when I delete data from MySQL, it still reappears in Elasticsearch, even if data is no longer present in MySQL DB. UPDATE and INSERT works fine, but DELETE isn't.
Also, I did the following:
Delete data in MySQL
Delete Elasticsearch Index and ES Kafka Sink
Create a new connector for ES in Kakfa
Now, the weird part is that all of my deleted data reappers here as well! When I check ES data before step (3), data wasn't there. But afterwards, this behaviour is observed.
Please help me fix this issue!
MySQL config :
"config": {
"connector.class": "io.debezium.connector.mysql.MySqlConnector",
"database.allowPublicKeyRetrieval": "true",
"database.user": "cdc-reader",
"tasks.max": "1",
"database.history.kafka.bootstrap.servers": "X.X.X.X:9092",
"database.history.kafka.topic": "schema-changes.mysql",
"database.server.name": "data_test",
"schema.include.list": "data_test",
"database.port": "3306",
"tombstones.on.delete": "true",
"delete.enabled": "true",
"database.hostname": "X.X.X.X",
"database.password": "xxxxx",
"name": "slave_test",
"database.history.skip.unparseable.ddl": "true",
"table.include.list": "search_ai.*"
},
Elasticsearch config:
"config": {
"connector.class": "io.confluent.connect.elasticsearch.ElasticsearchSinkConnector",
"type.name": "_doc",
"behavior.on.null.values": "delete",
"transforms.extractKey.field": "ID",
"tasks.max": "1",
"topics": "search_ai.search_ai.slave_data",
"transforms.InsertKey.fields": "ID",
"transforms": "unwrap,key,InsertKey,extractKey",
"key.ignore": "false",
"transforms.extractKey.type": "org.apache.kafka.connect.transforms.ExtractField$Key",
"transforms.key.field": "ID",
"transforms.key.type": "org.apache.kafka.connect.transforms.ExtractField$Key",
"name": "esd_2",
"transforms.unwrap.type": "io.debezium.transforms.ExtractNewRecordState",
"connection.url": "http://X.X.X.X:9200",
"transforms.InsertKey.type": "org.apache.kafka.connect.transforms.ValueToKey"
},

Answer 1

Debezium is reading the transaction log, not the source table, so the inserts and updates are always going to be read first, causing inserts and doc updates in Elasticsearch...
Secondly, did you create the sink connector with a new name or different one?
If the same one, the original consumer group offsets would not have changed, causing the consumer group to pickup at the offsets before you deleted the original connector
if a new name, and depending on the auto.offset.reset value of the sink connector consumer, you could be consuming the Debezium topic from the beginning, and causing data to get re-inserted into Elasticsearch, as mentioned. You need to check if your Mysql delete events are actually getting produced/consumed as tombstone values to cause deletes in Elasticsearch