Schema Registry fails on startup

Schema Registry
1

Hi Guys

I have a K8s cluster onto AWS using EKS services.
I also have a Kafka cluster on AWS using MSK.

I am trying to connect a new pod with schema-registry image to my kafka cluster, but it fails on start (And end up in a restart loop).

Let me paste my schema registry configuration here:

  SCHEMA_REGISTRY_DEBUG: "true"
  SCHEMA_REGISTRY_HOST_NAME: "my-schema-registry"
  SCHEMA_REGISTRY_KAFKASTORE_BOOTSTRAP_SERVERS: "SSL://<cluster1>:<port1>,SSL://<cluster2>:<port2>,SSL://<cluster3>:<port3>"
  SCHEMA_REGISTRY_KAFKASTORE_BOOTSTRAP_SERVERS_SECURITY_PROTOCOL: "SSL"
  SCHEMA_REGISTRY_LISTENERS: "http://0.0.0.0:8081"
  SCHEMA_REGISTRY_SSL_KEYSTORE_LOCATION: "/etc/kafka-ssl-keystore"
  SCHEMA_REGISTRY_SSL_KEYSTORE_PASSWORD: "****"
  SCHEMA_REGISTRY_SSL_KEY_PASSWORD: "*****"
  SCHEMA_REGISTRY_TRUSTSTORE_LOCATION: "/etc/kafka-ssl-truststore"
  SCHEMA_REGISTRY_TRUSTSTORE_PASSWORD: "****"

When server stats, it ends with

[2023-11-21 14:02:17,652] INFO [AdminClient clientId=adminclient-1] Cancelled in-flight API_VERSIONS request with correlation id 15 due to node -3 being disconnected (elapsed time since creation: 37ms, elapsed time since send: 37ms, request timeout: 3600000ms) (org.apache.kafka.clients.NetworkClient)
[2023-11-21 14:02:17,891] INFO [AdminClient clientId=adminclient-1] Node -2 disconnected. (org.apache.kafka.clients.NetworkClient)
[2023-11-21 14:02:44,870] INFO [AdminClient clientId=adminclient-1] Cancelled in-flight API_VERSIONS request with correlation id 91 due to node -3 being disconnected (elapsed time since creation: 36ms, elapsed time since send: 36ms, request timeout: 3600000ms) (org.apache.kafka.clients.NetworkClient)
[2023-11-21 14:02:45,084] INFO [AdminClient clientId=adminclient-1] Metadata update failed (org.apache.kafka.clients.admin.internals.AdminMetadataManager)
org.apache.kafka.common.errors.TimeoutException: Timed out waiting for a node assignment. Call: fetchMetadata
[2023-11-21 14:02:45,425] INFO [AdminClient clientId=adminclient-1] Node -1 disconnected. (org.apache.kafka.clients.NetworkClient)

Any idea what can be wrong?

I’ve read a lot, and so checked:

  • AWS VPC and security groups (Another pod in the cluster for KSQLDB works like a charm)
  • Property Bootstrap.Servers. As mentioned above, same property on KSQLDB reach the cluster
  • SSL configuration. Also copy&paste from KSQLDB success case

Thanks in advance
Sergio