Known Issues in Schema Registry

Learn about the known issues in Schema Registry, the impact or changes to the functionality, and the workaround.

CDPD-40380: Authorization checking issue when Kerberos is disabled

Due to an issue in Ranger, when Kerberos is disabled then it is not possible to check authorization.

  1. Open Schema Registry configuration in Cloudera Manager.
  2. Find the field.
  3. Replace GENERATED_RANGER_SERVICE_NAME with the actual name of the service.
  4. Restart the Schema Registry service.
CDPD-49304: AvroConverter does not support composite default values
AvroConverter cannot handle schemas containing a STRUCT type default value.
CDPD-60160: Schema Registry Atlas integration does not work with Oracle databases
Schema Registry is unable to create entities in Atlas if Schema Registry uses an Oracle database. The following will be present in the Schema Registry log if you are affected by this issue:
ERROR An error occurred while processing Atlas events.
java.lang.IllegalArgumentException: Cannot invoke com.hortonworks.registries.schemaregistry.AtlasEventStorable.setType on bean class 'class com.hortonworks.registries.schemaregistry.AtlasEventStorable' - argument type mismatch - had objects of type "java.lang.Long" but expected signature "java.lang.Integer"

This issue causes the loss of audit data on Oracle environments.

CDPD-59015: Schema Registry does not create new versions of schemas even if the schema is changed
Schema Registry uses a schema fingerprinting mechanism to differentiate between schemas. However, fingerprinting does not take into consideration the schema attributes of the field type. As a result, if you have two schemas where the only difference is that one has type attributes defined and the other does not, they will be considered identical by Schema Registry. For example, the following schemas are considered identical:
#Schema V1

#Schema V2

Notice that the only difference is that in the second schema, the local_timestamp_micros_long field has a logical type specified. In cases like this, the new version of the schema is not created, the initial version is used. This is true even if the data that is being produced has a new schema version. The ID of the first schema version is used and is put in the serialized record. The new schema version is not created.

This issue is common when using change data capture (CDC) connectors like the Debezium connectors. This is because CDC connectors create schemas with the logical type decimal based on the column type in the database schema. For example:
If the database schema changes (for example, the column type), it is possible that only scale changes, which is a schema attribute.
In this case, even though scale changed to 1, the first version of the schema is used where scale is 0. As a result, the data is consumed with the wrong scale.
Avoid using logical types or other attributes. Alternatively, ensure that there are no changes in the logical types or other attributes between schema versions.
OPSAPS-68708: Schema Registry might fail to start if a load balancer address is specified in Ranger
Schema Registry does not start if the address specified in the Load Balancer Address Ranger property does not end with a trailing slash (/).
Set the value of the RANGER_REST_URL Schema Registry environment variable to an address that includes a trailing slash.
  1. In Cloudera Manager, select the Schema Registry service.
  2. Go to Configuration.
  3. Find the Schema Registry Server Environment Advanced Configuration Snippet (Safety Valve) property and add the following:
    Value: [***RANGER REST API URL***]
    Replace [***RANGER REST API URL***] with an address that can be used by Schema Registry to access Ranger. Ensure that the address ends with a trailing slash. For example:
  4. Restart the Schema Registry service.