Add Amazon DynamoDB sink connector

[ethanlin01x]

Description

Add a native Rust sink connector for Amazon DynamoDB, allowing Iggy stream messages to be written directly into DynamoDB tables.

This is tracked in the connector ecosystem roadmap: #2753

Affected area / component

Connectors

Proposed solution

Crate: aws-sdk-dynamodb
(official AWS SDK, async/Tokio compatible)

Key design decisions:

1. Batching — batch_write_item has a hard limit of 25 items per request. The consume() handler will split incoming message batches into chunks of ≤25 before sending.

2. Idempotency — The connector will support a configurable partition_key_field (and optional sort_key_field) mapped from message payload. batch_write_item uses PutRequest which overwrites
   existing items on key conflict, making repeated delivery idempotent as long as the primary key is deterministic.

3. UnprocessedItems handling — batch_write_item can return partial failures via UnprocessedItems without throwing an error. The connector will retry unprocessed items with exponential backoff rather than silently dropping them.

4. Throughput errors — ProvisionedThroughputExceededException will be handled with retry logic compatible with both Provisioned and On-Demand capacity modes.

5. Item size limit — DynamoDB enforces a 400KB per-item limit. Oversized messages will be logged and skipped rather than failing the entire batch.

Alternatives considered

No response

Contribution

• I'm willing to submit a pull request to implement this feature

Good first issue

• I think this could be a good first issue for a new contributor