Hello, I am using the StreamingFileSink BulkFormat in my Flink stream processing job to output parquet files to S3. Now the StreamingFileSink.BulkFormatBuilder <https://ci.apache.org/projects/flink/flink-docs-master/api/java/org/apache/flink/streaming/api/functions/sink/filesystem/StreamingFileSink.BulkFormatBuilder.html>, does not have an option to set a custom rolling policy. It will roll the files whenever the checkpoint triggers <https://ci.apache.org/projects/flink/flink-docs-master/api/java/org/apache/flink/streaming/api/functions/sink/filesystem/rollingpolicies/OnCheckpointRollingPolicy.html>. It would be better to have a rolling policy based on both *size* and *time*. One option is to write our own StreamingFileSink, which does accept a custom rolling policy, but I suspect there might be some reason for this behaviour. I would like to get the opinion of Flink experts on this. And if there are any potential workarounds to get the desired behaviour.
Kind regards Ayush Verma
