=== Motivation Now, when a version-data of schema is lost, all schema data for that topic will be deleted. see: https://github.com/apache/pulsar/blob/0e149ef0484755d42e214f03003237299433c89a/pulsar-broker/src/main/java/org/apache/pulsar/broker/service/schema/SchemaRegistryServiceImpl.java#L527-L565
This will cause the following problems: - It is possible that the missing version is no longer in use, but the other versions of the schema data have also been deleted. - After all the schema data is deleted, the version counter will again start counting from 0. However, the old Message(already send and still in use) and the new Message(create with the new schema) will possibly use the same version of schemas, but the old Message cannot be parsed using the new schema. In my opinion: - Delete only the invalid record from Schema Meta Data. - The Schema version counter is always monotonically increased and is not used cyclically.
