This is part of the NServiceBus Upgrade Guide from Version 8 to 9, which also includes the following individual upgrade guides for specific components:
Transports
- AmazonSQS Transport Upgrade Version 6 to 7
- Azure Service Bus Transport Upgrade Version 3 to 4
- SQL Server Transport Upgrade Version 7 to 8
Hosting
Other
Delayed retries enabled by default
In Version 2, delayed retries are enabled by default. See the delayed retries documentation for more details.