Debezium with AWS MSK NOT_ENOUGH_REPLICAS - amazon-web-services

Question

I have a running debezium cluster in AWS, no issues with that. I want to give a try with AWS MSK. So I launched a cluster. Then I launched an EC2 for running my connectors.
Then installed confluent-kafka
sudo apt-get update && sudo apt-get install confluent-platform-2.12
By default the AWS MSK doesn't have schema registry, So I configured it from the connector EC2
Schema registry conf file:
kafkastore.connection.url=z-1.bhuvi-XXXXXXXXX.amazonaws.com:2181,z-3.bhuvi-XXXXXXXXX.amazonaws.com:2181,z-2.bhuvi-XXXXXXXXX.amazonaws.com:2181
kafkastore.bootstrap.servers=PLAINTEXT://b-2.bhuvi-XXXXXXXXX.amazonaws.com:9092,PLAINTEXT://b-4.bhuvi-XXXXXXXXX.amazonaws.com:9092,PLAINTEXT://b-1.bhuvi-XXXXXXXXX.amazonaws.com:9092
Then /etc/kafka/connect-distributed.properties file
bootstrap.servers=b-4.bhuvi-XXXXXXXXX.amazonaws.com:9092,b-3.bhuvi-XXXXXXXXX.amazonaws.com:9092,b-2.bhuvi-XXXXXXXXX.amazonaws.com:9092
plugin.path=/usr/share/java,/usr/share/confluent-hub-components
Install connector:
confluent-hub install debezium/debezium-connector-mysql:latest
start the service
systemctl start confluent-schema-registry
systemctl start confluent-connect-distributed
Now everything started. Then I created a mysql.json file.
{
"name": "mysql-connector-db01",
"config": {
"name": "mysql-connector-db01",
"connector.class": "io.debezium.connector.mysql.MySqlConnector",
"database.server.id": "1",
"tasks.max": "3",
"database.history.kafka.bootstrap.servers": "172.31.47.152:9092,172.31.38.158:9092,172.31.46.207:9092",
"database.history.kafka.topic": "schema-changes.mysql",
"database.server.name": "mysql-db01",
"database.hostname": "172.31.84.129",
"database.port": "3306",
"database.user": "bhuvi",
"database.password": "my_stong_password",
"database.whitelist": "proddb,test",
"internal.key.converter.schemas.enable": "false",
"key.converter.schemas.enable": "false",
"internal.key.converter": "org.apache.kafka.connect.json.JsonConverter",
"internal.value.converter.schemas.enable": "false",
"value.converter.schemas.enable": "false",
"internal.value.converter": "org.apache.kafka.connect.json.JsonConverter",
"value.converter": "org.apache.kafka.connect.json.JsonConverter",
"key.converter": "org.apache.kafka.connect.json.JsonConverter",
"transforms": "unwrap",
"transforms.unwrap.type": "io.debezium.transforms.ExtractNewRecordState"
"transforms.unwrap.add.source.fields": "ts_ms",
}
}
Create debezium connector
curl -X POST -H "Accept: application/json" -H "Content-Type: application/json" http://localhost:8083/connectors -d #mysql.josn
Then its stated giving this error in the connector EC2.
Dec 20 11:42:36 ip-172-31-44-220 connect-distributed[2630]: [2019-12-20 11:42:36,290] WARN [Producer clientId=producer-3] Got error produce response with correlation id 844 on topic-partition connect-configs-0, retrying (2147482809 attempts left). Error: NOT_ENOUGH_REPLICAS (org.apache.kafka.clients.producer.internals.Sender:637)
Dec 20 11:42:36 ip-172-31-44-220 connect-distributed[2630]: [2019-12-20 11:42:36,391] WARN [Producer clientId=producer-3] Got error produce response with correlation id 845 on topic-partition connect-configs-0, retrying (2147482808 attempts left). Error: NOT_ENOUGH_REPLICAS (org.apache.kafka.clients.producer.internals.Sender:637)
Dec 20 11:42:36 ip-172-31-44-220 connect-distributed[2630]: [2019-12-20 11:42:36,492] WARN [Producer clientId=producer-3] Got error produce response with correlation id 846 on topic-partition connect-configs-0, retrying (2147482807 attempts left). Error: NOT_ENOUGH_REPLICAS (org.apache.kafka.clients.producer.internals.Sender:637)
Dec 20 11:42:36 ip-172-31-44-220 connect-distributed[2630]: [2019-12-20 11:42:36,593] WARN [Producer clientId=producer-3] Got error produce response with correlation id 847 on topic-partition connect-configs-0, retrying (2147482806 attempts left). Error: NOT_ENOUGH_REPLICAS (org.apache.kafka.clients.producer.internals.Sender:637)
It never stops this error message.
Describe of connect-configs
Topic:connect-configs PartitionCount:1 ReplicationFactor:1 Configs:cleanup.policy=compact
Topic: connect-configs Partition: 0 Leader: 2 Replicas: 2 Isr: 2

Answer 1

MSK sets min.in.sync.replicas to 2 for all topics by default (see https://docs.aws.amazon.com/msk/latest/developerguide/msk-default-configuration.html)
It possible that Kafka Connect is producing using ACKs="all" and, since you only have one copy of your topic, it never achieves enough quorum.