#417 · bluetape4k-aws · 1.0.0

AWS Streams Shard Consumer Lab

Play the same shard lifecycle across Kinesis and DynamoDB Streams to compare discovery, ordering, bounded concurrency, checkpoints, and failure boundaries.

Execution scenarios

Step0 / 8

Amazon Kinesis Data Streams

Semaphore(maxShardConcurrency) · Sequential polling inside each shard

Waiting
  1. 0Ready
  2. 1Discover shards
  3. 2Build shard graph
  4. 3Apply ordering gate
  5. 4Start shard
  6. 5Poll records
  7. 6Deliver downstream
  8. 7Save checkpoint
  9. 8Finish shard
Current action

Guaranteed contract

Next transition

Durable KinesisCheckpoint.ShardEnd

Amazon DynamoDB Streams

flatMapMerge(maxShardConcurrency) · Sequential parent-to-child traversal per root tree

Waiting
  1. 0Ready
  2. 1Discover shards
  3. 2Build shard graph
  4. 3Apply ordering gate
  5. 4Start shard
  6. 5Poll records
  7. 6Deliver downstream
  8. 7Save checkpoint
  9. 8Finish shard
Current action

Guaranteed contract

Next transition

Iterator completion unlocks child traversal

Adapter-owned

Bounded pagination and concurrency · per-shard order · cancellation propagation · emit-before-checkpoint · at-least-once resume

│ at-least-once │
Caller-owned

Durable stores · idempotency and deduplication · retry and retention policy · reshard operations · client lifecycle