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Buz's schema registry functionality consists of several parts:

  1. An onboard cache which stores schemas so incoming payloads can be validated and annotated in microseconds.
  2. A configurable backend, from which schemas are sourced before being stored in the onboard cache.
  3. HTTP routes used to interact with schemas directly or purge the onboard cache.

Onboard Schema Registry Cache

The onboard schema registry cache stores schemas. If a schema is not available from the cache when needed, said schema is sourced from the configured backend.

The onboard schema registry cache ttl and the max size are both configurable.

If a schema is not used within the configured $registry.ttlSeconds it is purged and will be sourced from the backend when needed next. If the onboard schema cache exceeds $registry.maxSizeBytes it will purge schemas in LRU fashion.

For example configuration, please refer to the registry section of the bootstrap configuration.

Schema Registry Backends

Buz supports storing schemas in many different backends which are outlined along with their associated docs below:

BackendTypeSupported?MaintainerMore Details
FileBuzYes ✅🐝Docs
HTTP/SBuzYes ✅🐝Docs
Google Cloud StorageObject StorageYes ✅🐝Docs
AWS S3Object StorageYes ✅🐝Docs
MinioObject StorageYes ✅🐝Docs
PostgresDatabaseYes ✅🐝Docs
MysqlDatabaseYes ✅🐝Docs
MongodbDatabaseYes ✅🐝Docs
ClickhouseDatabaseYes ✅🐝Docs
MaterializeSaasYes ✅🐝Docs
Kafka Schema RegistryRegistryNot yet ⚠️This could be you.-
Snowplow IGLURegistryNot yet ⚠️This could be you.-

Schema Registry HTTP Routes


Any schema in the configured backend can be accessed under the /s/ route using /s/$PATH_TO_SCHEMA or /s/$SCHEMA_NAME.

For example

When running Buz using either the quickstart or make boostrap, you can access the Buz config schema at http://localhost:8080/s/io.silverton/buz/internal/config/app/v1.0.json.

Cache Purge

The onboard schema registry cache can be explicitly purged by sending either a GET or POST to /c/purge.

This is simply an operational lever to get the most-recent schema versions onto collectors while they are running.

For example

After running the quickstart or make boostrap you can easily purge all locally-cached schemas by navigating to http://localhost:8080/c/purge