Have you tried Pulsar or Redpanda? Both seem mature enough and provide decent performance to probably meet your needs. What I hear is that Redpanda is a lot easier to manage than Kafka.
Redpanda Community Edition is licensed with the Redpanda Business Source License (BSL). The core features are free and source-available.
This license was inspired by MariaDB and CockroachDB and "for 99.999% of users, restrictions will not apply". The big restriction is that users "cannot provide Redpanda as a commercial streaming or queuing service to others" which is primarily to deter large cloud vendors from taking our work and impacting our ability to operate as a business.
Here are some links for more details on how we came to this decision and how we license all our products and features.
