Too low interval between flushes

[blazzup]

We had problems writing a busy stream to Firehose, since it seems that the limit of 500 records per PutRecordBatch is also the max number of records per second you can send.

With default settings, Firehose was getting throttled and the actual throughput was very low. This was solved by adding a delay in Flink before sending to the sink and now our throughtput almost reaches the limit of 1MB/s for our region.

I guess similar could be achieved by increasing bufferTimeoutBetweenFlushes. Shouldn't this parameter be increased by default then or am I missing something else?