Enhanced fan-out enables consumers to receive records from a stream with throughput of up to 2 MB of data per second per shard. This throughput is dedicated, which means that consumers that use enhanced fan-out don’t have to contend with other consumers that are receiving data from the stream. Kinesis Data Streams pushes data records from the stream to consumers that use enhanced fan-out. Therefore, these consumers don’t need to poll for data.
For standard iterators, Lambda polls each shard in your Kinesis stream for records at a base rate of once per second. When more records are available, Lambda keeps processing batches until the function catches up with the stream. The event source mapping shares read throughput with other consumers of the shard.
To minimize latency and maximize read throughput, create a data stream consumer with enhanced fan-out. Enhanced fan-out consumers get a dedicated connection to each shard that doesn’t impact other applications reading from the stream. Stream consumers use HTTP/2 to reduce latency by pushing records to Lambda over a long-lived connection and by compressing request headers. You can create a stream consumer with the Kinesis RegisterStreamConsumer API.
aws kinesis register-stream-consumer --consumer-name con1 \ --stream-arn arn:aws:kinesis:us-east-2:123456789012:stream/lambda-stream
When you configure Event source mapping, use the consumer name created above as the consumer.
You can also try the template from serverlessland