Messages

A policy with a partition key reports it on the message object, since a key routes one record and names no stream.

A key named on the policy with KinesisPublishSettings applies to every record that leaves through it. So the message object of those records carries it as partitionKey in its x-ruststream-kinesis object. The stream stays on the channel: one message type published to two streams describes both with one message object. A policy with no key adds no object to the message. A key named on one publish with the partition_key step describes one record, not the mount, so it is not in the document.

Example

The receipts leave through a policy keyed tenant-acme.

Macros

examples/kinesis_asyncapi.rs

fn service(broker: KinesisBroker) -> RustStream {
    // The label is the server's key in the document.
    RustStream::new(AppInfo::new("orders", "0.1.0")).with_broker_labeled("kinesis", broker, |b| {
        // Every receipt carries one key, so they share a shard and keep their order.
        b.include(confirm)
            .out_reply(Publish::default())
            .partition_key("tenant-acme");
    })
}

Manual

examples/manual/kinesis_asyncapi.rs

fn service(broker: KinesisBroker) -> RustStream {
    // The label is the server's key in the document.
    RustStream::new(AppInfo::new("orders", "0.1.0")).with_broker_labeled("kinesis", broker, |b| {
        // Every receipt carries one key, so they share a shard and keep their order.
        b.include(subscriber(orders(), Confirm).reply().build())
            .out_reply(Publish::default())
            .partition_key("tenant-acme");
    })
}

The message object of Receipt in the document:

tests/snippets/asyncapi-message.json

{
  "x-ruststream-kinesis": {
    "partitionKey": "tenant-acme"
  }
}