title: Amazon Kinesis Firehose Buffering to S3
body: <p>I'm attempting to price out a streaming data / analytic application deployed to AWS and looking at using Kinesis Firehose to dump the data into S3.</p>
  
  <p>My question is, when pricing out the S3 costs for this, I need to figure out out how many PUT's I will need.</p>
  
  <p>So, I know the Firehose buffers the data and then flushes out to S3, however I'm unclear on whether it will write a single "file" with all of the records accumulated up to that point or if it will write each record individually.  </p>
  
  <p>So, assuming I set the buffer size / interval to an optimal amount based on size of records, does the number of S3 PUT's still equal the number of records OR the number of flushes that the Firehose performs?</p>