I have a need where I wanted to push some data to S3 from lambda. The data coming to Lambda is from a Dynamodb streams. Since, for pushing to S3 bucket, use of Firehose is considered best as it batches and buffers the data before pushing to S3 as well as provide the retry strategy. So, I am using Firehose instead of directly pushing to S3.
But I observe lot of people push data from Lambda to Kinesis Stream from which data is pushed to Kinesis Firehose instead of directly pushing to Firehose from AWS Lambda. Is there any reason of doing it this way? Any benefits? What are the drawbacks of pushing to Kinesis firehose directly?
If Amazon Kinesis Data Firehose meets your needs, then definitely use it! It takes care of most of the work for you, compared to normal Kinesis Streams.
The only time you would not use Firehose is when you have a different destination (eg you want to process the data on Amazon EC2 instances) or you want more control of the streams and shards (eg to process certain producers on specific shards to retain ordering on a per-shard basis).