Stream processors listen for data from a streaming service such as Kinesis or DynamoDB Streams. Deploying a stream processor is completely declarative. We configure a function with the stream event type and the pertinent settings, such as the type, arn, batchSize, and startingPosition. The arn is set dynamically using a CloudFormation variable, ${cf:cncb-event-stream-${opt:stage}.streamArn}, that references the output value of the cnbc-event-stream stack.
Streams are the only resources that are shared between autonomous cloud-native services.
We will discuss batch size and starting position in detail in both Chapter 8, Designing for Failure, and Chapter 9, Optimizing Performance. For now, you may have noticed that the new ...
