In order to use the transactional session feature with RavenDB persistence, add a reference to the NServiceBus. NuGet package.
Configuration
To enable the transactional session feature:
var persistence = config.UsePersistence<RavenDBPersistence>();
persistence.EnableTransactionalSession();
Opening a session
To open a RavenDB transactional session:
using var childBuilder = builder.CreateChildBuilder();
var session = childBuilder.Build<ITransactionalSession>();
await session.Open(new RavenDbOpenSessionOptions());
// use the session
await session.Commit();
Multi-tenancy support
The specific tenant database name is retrieved from message headers as configured in the SetMessageToDatabaseMappingConvention-method. This header needs to be set in the options so that the necessary information is available when storing operations and interacting with the outbox.
using var childBuilder = builder.CreateChildBuilder();
var session = childBuilder.Build<ITransactionalSession>();
await session.Open(
new RavenDbOpenSessionOptions(
new Dictionary<string, string>
{
// information is added to the message headers for the
// `SetMessageToDatabaseMappingConvention`-method
{"tenantDatabaseName", "tenantA-databaseName"}
}));
// use the session
await session.Commit();
Transaction usage
Message and database operations made via the the transactional session are committed together once the session is committed:
await session.Open(new RavenDbOpenSessionOptions());
// add messages to the transaction:
await session.Send(new MyMessage());
// access the database:
var ravenSession = session.SynchronizedStorageSession.RavenSession();
await session.Commit();
See the RavenDB shared session documentation for further details about using the transaction.
In order to guarantee atomic consistency across message and database operations, the outbox must be enabled. Otherwise Commit executes database modifications first and then messages are dispatched with best-effort.