The message doesn't have to be dispatched immediately after sending, it can be delivered at a later time if necessary.
Delaying a message is done using
SendOptions and the
DelayDeliveryWith method. This allows to defer the sending of a message to any endpoint. The behavior of delayed handling using
DelayDeliveryWith can be seen in Delayed Delivery Sample.
Deferwill also change the message's reply-to address to the endpoint deferring the message. Calling
Replyon a deferred message will send the reply to itself.
Delays delivery of a message for a specified duration.
var sendOptions = new SendOptions(); sendOptions.DelayDeliveryWith(TimeSpan.FromMinutes(30)); await handlerContext.Send(new MessageToBeSentLater(), sendOptions) .ConfigureAwait(false); // OR await endpoint.Send(new MessageToBeSentLater(), sendOptions) .ConfigureAwait(false);
Delays delivery of a message until a specified point in time.
var options = new SendOptions(); options.DoNotDeliverBefore(new DateTime(2016, 12, 25)); await handlerContext.Send(new MessageToBeSentLater(), options) .ConfigureAwait(false); // OR await endpoint.Send(new MessageToBeSentLater(), options) .ConfigureAwait(false);
Delayed delivery of messages is supported when one of the following requirements are met:
- The transport supports delayed delivery natively.
- The Timeout Manager feature is enabled and the endpoint is not a send-only endpoint.
When deferring a message, it is sent to the Timeout Manager requesting it to deliver the message at a later time or deferred by using the transports native capability to defer messages.
NServiceBus provides delayed deliver feature for transports that don't have native support for delayed message delivery, i.e. for MSMQ and SQL Server transports. Transports that support delayed message delivery natively don't require persistence. To learn more about NServiceBus delayed message store refer to the Timeout Manager article.