My HiveMQ Serverless Kafka Integration does not work
Problem
A user created a Kafka Integration in the HiveMQ Cloud Serverless console, all settings seem correct but the UI shows Internal error 500 when trying to save the configuration. Why and what to do?
Root cause
Internal error 500 indicates that the config did not pass the verification of the HiveMQ Cloud Serverless Kafka Integration.
For Serverless, we support Plain and SCRAM-SHA-512 (not SCRAM-SHA-256).
Our preflight validation tries to connect to Kafka with the SASL_SSL security protocol.
If your Kafka server is configured with SASL_PLAINTEXT, this is the root cause of the Internal Error 500 error
Solution
Use SASL_SSL in your Kafka server rather than SASL_PLAINTEXT to make it work