Google Cloud Storage sink connector naming and data formats

The Apache Kafka Connect® GCS sink connector by Aiven enables you to move data from an Aiven for Apache Kafka® cluster to a Google Cloud Storage bucket for long term storage. The full connector documentation is available in the dedicated GitHub repository.

File name format

The connector uses the following format for output files (blobs)


The file name format has the following building blocks:

  • <prefix>: the file name prefix, useful, for example, to define subdirectories in the storage bucket

  • <topic>: the source Apache Kafka topic name

  • <partition>: the source Apache Kafka topic’s partition number

  • <start-offset>: the offset of the first record in the file

  • [.gz]: the file suffix, added when compression is enabled and depending on compression type

Data format

The connector output files are text files that contain one record per line (separated by \n).

There are two types of data format available:

  • Flat structure: it’s the default data format, where the field values are separated by comma (CSV).

    You can use the CSV format by setting the format.output.type to csv.

  • Complex structure: the file stores messages in the format of JSON lines. It contains one record per line and each line is a valid JSON object (jsonl).

    You can use the JSON format by setting the format.output.type to jsonl.