Publisher Mode

When an endpoint uses a persistence store, its publisher send calls communicate outbound messages to the store, as well as to the endpoint’s regular transports. Depending upon application requirements, the publisher send call can also wait for the store to confirm that it has received and stored each message. Different sequences of these subtask elements produce different qualities of service.

Administrators must select the publisher mode that best suits the application’s needs.

Persistence Store Publisher Modes
Publisher Mode JSON Attributte Description
Store - Send store_send_noconfirm Highest throughput. Minimal message latency. More robust delivery than regular reliability.

Send the message to the store. Do not wait for confirmation.

Send the message on the endpoint’s transports.

There is no back pressure from the persistence service to the producer application. As a result the producer must ensure that it does not send faster than the persistence services can replicated data on the network (or write it to disk, if disk persistence is enabled).

Data can be lost if the connection between the producer and the persistence services is broken for any reason while the producer is sending. This includes network failures and restarts or upgrades of the persistence services.

Store - Confirm - Send store_confirm_send Guarantees delivery in exchange for lower throughput and higher message latency.

If the send call succeeds, then the store guarantees that the appropriate durable subscribers will eventually receive the message. Conversely, if the store operation fails, the send call also fails, and subscribers do not receive the message through direct transports, nor from the store. The exact behavior depends on the send policy. See .

Send the message to the store.

Wait for the cluster to confirm storage.

Send the message on the endpoint’s transports.

There is back pressure from the persistence service to the producer application. The producer will automatically be throttled to a sustainable data rate.