A DynamoDB implementation of the
PersistedEventRepositorytrait in cqrs-es.
AWS' DynamoDb is fast, flexible and highly available, but it does set some limitations that must be considered in the design of your application.
Events are inserted in a single transaction, which limits the number of events that can be handled from a single command using this repository. To operate correctly a command must not produce more than
- 25 events if using an event store without snapshots
- 24 events if using snapshots or an aggregate store
A single event should never reach this size, but a large serialized aggregate might. If this is the case for your aggregate beware of using snapshots or an aggregate store.
This could have the same ramifications as the above for snapshots or an aggregate store. Additionally, an aggregate instance with a large number of events may reach this threshold. To prevent an error while loading or replaying events, set the streaming channel size to a number that ensures you won't exceed this threshold.
Requires access to DynamoDb with existing tables. This can be created locally using the included
docker-compose.yml file with CLI configuration of test tables included in the Makefile.
To prepare a local test environment (requires a local installation of Docker and AWS CLI):
docker-compose up -dmake configure
Note that this crate used the AWS DynamoDb Rust SDK, which is currently in Developer Preview. This means that any bugs will be addressed but the underlying interfaces may still be changed resulting in significant changes within this crate. See the AWS SDK public roadmap for more information.
It is recommended that tables are configured to allow only transactions. See: https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/transaction-apis-iam.html
Things that could be helpful:
- User guide along with an introduction to CQRS and event sourcing.
- Demo application using the warp http server.
- Change log
