Query Avro schema from schema registry if it is missing #951
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| public Schema getSchema(String topic) { | ||
| Schema schema = schemas.get(topic); | ||
| if (schema == null) { | ||
| throw new IllegalStateException("Avro schema not found for topic " + topic); | ||
| try { | ||
| SchemaMetadata schemaMetadata = schemaRegistryClient.getLatestSchemaMetadata(topic + "-value"); |
There was a problem hiding this comment.
This seems odd to me. Who defines that convention: 'topic_name-value'?
There was a problem hiding this comment.
basically, there are three strategies configurable in Kafka to work with Schema Registry explained here. The default one which most of the deployments use is "TopicNameStrategy". In this strategy
- The subject name for the value is "topic-value"
- The subject name for the key is "key-value"
There was a problem hiding this comment.
is getSchema() only interested in value schema (or key schema as well)?
There was a problem hiding this comment.
Only value schema. Key is only an internal Kafka thing and is not gonna be stored in the Avro/AvroParquet files
|
Looks good. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
As mentioned #894, secor fails if
secor.file.reader.writer.factory=com.pinterest.secor.io.impl.AvroParquetFileReaderWriterFactorykafka.useTimestamp=trueThe writer is going to ask
SecorSchemaRegistryClientfor Avro schema for the writer. But that only has the schema in the cache if there has been a call fordecodeMessage. However, if we use the message timestamp, it won't need to decode the message.I updated the code to query the schema registry in order to update the cache. It uses the standard subject name for a Kafka topic as "kafka_topic-value" to query the schema.