Service Bus
The Service Bus provides secure messaging and relay capabilities that enable building distributed and loosely-coupled applications in the cloud, as well hybrid application across both private and public clouds. It supports multiple messaging protocols and patterns and handles delivery assurance, reliable messaging and scale for your applications. The Service Bus is a managed service that is operated by Microsoft and has a 99.9% monthly SLA.
There are many practical uses for the Service Bus. Some common uses include:
Hybrid applications
The Service Bus enables you to securely connect and integrate enterprise systems running in your private cloud with applications running on Windows Azure. This makes it easier to extend solutions to the cloud without having to port or migrate all of your data or code from an existing enterprise datacenter to Windows Azure.
Mobile applications
The Service Bus enables you to easily build applications that can distribute event notifications and data to occasionally-connected clients, such as smart phones or tablets. You can expose notifications or events from an application running either in Windows Azure or in your private cloud environment, and ensure that they are ultimately delivered to mobile devices.
Loosely coupled architectures
The Service Bus enables you to build loosely-coupled systems that are more resilient to network failure and can more easily scale out based on demand. The Service Bus can act as the connecting broker between the different components of a system, eliminating direct dependencies between different components. Easily leverage the Service Bus to architect applications that support application load balancing.
Capabilities and Benefits of Service Bus
Service Bus messaging
- Service Bus Queues offer a reliable, highly scalable way to store messages as they travel between systems without losing messages in the event of connectivity failure.
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Service Bus Topics and Subscriptions implement a publish/subscribe pattern that delivers a highly scalable, flexible, and cost-effective way to publish messages from an application and deliver them to multiple subscribers.
Service Bus connectivity
- The Service Bus Relay enables applications hosted inside Windows Azure to securely call back to private cloud applications hosted in your own datacenter behind a firewall and vice versa. The relay service avoids the need to instantiate and setup a new connection on each call and makes connectivity faster and more reliable. It also supports the ability to integrate applications across existing NATs and firewalls. The relay service supports a variety of different transport protocols and Web services standards, including REST, SOAP, and WS-*.
- Companies can use the Service Bus relay to expose just the information they want from their private cloud environment, which creates a more secure architecture than opening up a VPN. Enterprises can use a SOA-based architecture and expose just the services they want to deliver from their on-premise data centers.
Pricing and Metering for Service Bus
Effective December 10, 2011, the Service Bus will be offered at no charge (except for standard data transfer fees). This promotional period will end for all billing months beginning after March 31, 2012. The Service Bus will then be charged at the following rates:
- $0.01 per 10,000 messages
- $0.10per 100 relay hours (this only applies when using the Service Bus relay capability)
Messages are charged based on the number of messages sent to, or delivered by, the Service Bus during the billing month. This includes delivery of “null” messages in response to receive requests against empty queues/subscriptions. Messages over 64KB in size will be charged an additional message for each additional 64KB of data (rounded up).
Relay hours will be charged from the time of creation to deletion (from when the first listener opens to when the last listener closes on the endpoint) and rounded up to the next whole hour. There is no relay hour charge if you are only using Service Bus Queues and Topics.
In addition to the prices noted above for the Service Bus, you will also be charged for the associated data transfers for egress outside the data center where your app is provisioned.
Visit MSDN to get in-depth information on the Service Bus.