NamingService
-The Naming service allows youto assign DNS-capable names to your service, which makes the serviceeasilyresolvable over the Internet.
ServiceRegistry
-The AppFabric Service Busprovides a registration and discovery service for service endpoints called the serviceregistry.
classProgram
{
static void Main(string[] args)
{
ServiceHosthost = new ServiceHost(typeof(EnergyManagementService));
ServiceRegistrySettingssettings = new ServiceRegistrySettings();
settings.DiscoveryMode= DiscoveryType.Public;
foreach(ServiceEndpoints in host.Description.Endpoints)
s.Behaviors.Add(settings);
host.Open();
Console.WriteLine("Press[Enter] to exit");
Console.ReadLine();
host.Close();
}
}
The defaultsetting for the public discovery is set to private, so if you don’t set thediscovery type to
public, yourservice won’t be discoverable publicly
the serviceopens an outbound connection with a bidirectional socket to
theAppFabric Service Bus relay service.Note that you don’t need to open anyinbound ports in your firewall or NAT router for the end-toend
communicationto work when using the AppFabric Service Bus. Therefore, the listenerapplication
can berunning behind a firewall, NAT router, and even with a dynamic IP address.Theclient
applicationinitiates an outbound connection to the relay service with the appropriateservice address
that can beresolved from the service registry. The AppFabric Service has a load-balancedarray of nodes
that providethe necessary scalability to the client and service communications. When theclient sends a
message tothe service, the message is relayed by the relay service to the appropriatenode that is holding
reference tothe listener’s endpoint. Finally, the relay service sends the message to theservice over the
listener’soutbound bidirectional socket.
AppFabricService Bus Bindings
Thefundamental difference between AppFabric Service Bus bindings and WCF bindingsis at the transport level, which is completely opaque to the programming model
MessageBuffer
TheAppFabric Service Bus bindings for the WCF-style communications are designedfor synchronous
communicationsbetween the sender and the receiver. This means the receiver must be running to receive themessage sent by the sender; otherwise, the message will get lost TheAppFabric Service Bus offers a message buffer service for storing messages in atemporary
cache forasynchronous communication between clients and servers.The messages stored in amessage buffer on the serverdon’t survive server reboots
Queues andTopics
Queuesprovide a durablemessaging mechanism, and Topics builds upon the queuing structure by adding theability to
createtopics for which consumers can create rules by which to filter messages
Note Queuesand Topics are replacing Message Buffers, which will be deprecated in futurereleases.
ProAzureEnergy Service Example
-Service Binding
-NetOnewayRelayBinding
-Relay Security
TransportClientEndpointBehaviorsharedSecretServiceBusCredential =
newTransportClientEndpointBehavior();
sharedSecretServiceBusCredential.CredentialType=
TransportClientCredentialType.SharedSecret;
sharedSecretServiceBusCredential.Credentials.SharedSecret.IssuerName=
issuerName;
sharedSecretServiceBusCredential.Credentials.SharedSecret.IssuerSecret=
issuerKey;
ServiceHostHost = new ServiceHost(serviceType);
Host.Description.Endpoints[0].Behaviors.Add(behavior);
-Message Security
Message security refers to thesecurity of the message as it travels from client to service via the AppFabric
Service Bus.As discussed earlier, the AppFabric Service Bus API offers four options formessage security
in theenumeration Microsoft.ServiceBus.EndToEndSecurityMode: None, Transport,Message, and
TransportWithMessageCredentials.netOnewayRelayBinding doesn’t support
TransportWithMessageCredentials.
-Service Endpoints
The endpoint
consists offour main attributes: the address of the endpoint, a binding that defines whatprotocol a
client canuse to communicate with the endpoint, a service contract that defines theoperations available
for theclient to call, and a set of behaviors defining the local behavior of theendpoint
<endpoint
address="sb://{yourservice namespace}
.servicebus.windows.net/OnewayEnergyServiceOperations/"
behaviorConfiguration="sharedSecretClientCredentials"
binding="netOnewayRelayBinding"
bindingConfiguration="default"
name="RelayEndpoint"
contract="EnergyServiceContract.IOnewayEnergyServiceOperations"/>
-Service Hosting
TransportClientEndpointBehaviorbehavior =
ServiceBusHelper.GetUsernamePasswordBehavior(issuerName,issuerKey);
Host = newServiceHost(typeof(OnewayEnergyServiceOperations));
Host.Description.Endpoints[0].Behaviors.Add(behavior);
Host.Open();
AppFabricMessaging: Queues and Topics
AppFabricService Bus Queues vs. Azure Storage Queues
So, what arethe differences, and when should each be used?AppFabric Queues provide a richer messaging environment in that it supportsprotocols other
than HTTP/S,in addition to enabling advanced messaging features:
• WCFbinding
• Poisonmessage handling
•Dead-lettering
• Transactions
• Groups
• Sessions
• duplicatedetection Message Deferral/Scheduled Delivery
•Authentication via ACS
Also, bothservices support REST over HTTP, but if you require a higher level ofperformance , you
can usebi-directional TCP with the AppFabric Queue
Another keydifference is that AppFabric Queues support the use of sessions. With this, yougain the
ability toguarantee First-In First-Out ordering, as well as the ability to supportExactly-Once delivery
If any ofthe mentioned capabilities are required, you will need to use AppFabric Queues.If you
simply wantto use a queue to support cross-service communication, such as inter-rolecommunication
at scale,then AppFabric Queues could be overkill. In this case, Azure Storage Queuesshould be
sufficient.
**AddingSession State to a Queue
AppFabricService Bus Topics
HandlingProblem Messages and Abandonment
-Invalid/Poison Messages
-Server Error During MessageProcessing
