When an endpoint fails to process a message successfully, NServiceBus automatically retries the message the configured number of times. If the message can not be processed successfully even after the retried attempts, NServiceBus forwards the message to a designated error queue.
The default error queue name is
error but some transports require it to be explicitly configured.
IProvideConfiguration is deprecated in Version 7.
Before a message is moved to the error queue it is possible to inspect and modify its headers including error forwarding headers.
The following snippet shows how to configure header customizations and perform header value modification.
var recoverability = endpointConfiguration.Recoverability();
headers["NServiceBus.ExceptionInfo.Message"] = "message override";
Administrators should monitor the error queue in order to detect when problems occur. The message in the error queue contains relevant information such as the endpoint that originally processed the message and exception details. With this information, an administrator can investigate the problem and solve it, for example, bringing up a database that went down.
Monitoring and handling of failed messages with ServicePulse provides access to full exception details including the stack-trace. ServiceInsight offers advanced debugging capability providing additional information like exception details as well as visualizing the flow of messages. Both ServiceInsight and ServicePulse provide
retry functionality that sends a failed message from the error queue back to the originating endpoint for re-processing. For more details on how to retry a message using ServicePulse, see Introduction to Failed Messages Monitoring in ServicePulse. To retry a message using ServiceInsight, see Managing Errors and Retries in ServiceInsight.
If either ServicePulse or ServiceInsight are not available in the environment, the
retry operation can be performed using the native management tools appropriate for the selected transport: