diff --git a/README.md b/README.md index d264d8a..d7650f2 100644 --- a/README.md +++ b/README.md @@ -1,12 +1,14 @@ Schema Registry Transfer SMT ============================ -A [Kafka Connect Single Message Transformation (SMT)][smt] that reads the serialized [wire format header][wire-format] of Confluent's `KafkaAvroSerializer`, performs a lookup against a source [Confluent Schema Registry][schema-registry] for the ID in the message, and registers that schema into a destination Registry for that topic/subject under a new ID. +A [Kafka Connect Single Message Transformation (SMT)][smt] that reads the serialized [wire format header][wire-format] of Confluent's `KafkaAvroSerializer`, performs a lookup against a source [Confluent Schema Registry][schema-registry] for the ID in the message, and registers that schema into a destination Registry for that topic/subject under a new ID. -To be used where it is not feasible to make the destination Schema Registry as a follower to the source Registry, or when migrating topics to a new cluster. +To be used where it is not feasible to make the destination Schema Registry as a follower to the source Registry, or when migrating topics to a new cluster. > _Requires that the Kafka Connect tasks can reach both Schema Registries._ +This transform doesn't mirror the contents of the `_schemas` topic, so therefore each registry can be completely isolated from one another. As a side-effect of this, the subject configurations that might be applied to the `/config` endpoint in the source registry are not copied to the destination. In other words, you might get schema registration errors if using differing compatibility levels on the registries. Just a heads-up. + Example Kafka Connectors where this could be applied. - [Comcast/MirrorTool-for-Kafka-Connect](https://github.com/Comcast/MirrorTool-for-Kafka-Connect) - Code was tested with this first, and verified that the topic-renaming logic of this connector worked fine with this SMT.