HomeBlogCloud ComputingAzure Service Bus: Features and Offerings

Azure Service Bus: Features and Offerings

05th Sep, 2023
view count loader
Read it in
16 Mins
Azure Service Bus: Features and Offerings

Any application, device, or service that runs in the cloud may be connected to any other application or service via the messaging service Azure Service Bus. It serves as a communications foundation as a result for cloud-based or cross-platform applications. 

It can be difficult and challenging to integrate two separate systems because of issues with both system’s availability, processing speed, scale, and other factors. Enabling asynchronous communication across many services is one of several suggestions for building and creating cloud-based applications that is essential to the system's dependability, scalability, and effectiveness. 

Cloud apps, on-premises applications, and Azure's own services are all connected through highly scalable and dependable Enterprise Messaging Service known as Microsoft Azure Service Bus. Cloud applications, client applications of any kind, and local apps operating behind a firewall may all use Azure Service Bus. To get certified in Cloud Computing, enroll for Cloud Computing certification. 

What are Message Queues?

Message Queues are a solution to the problems encountered during integration in distributed systems. It is an effective method of facilitating asynchronous connections across multiple software services. Asynchronous communication is made possible via message queues, which implies that the endpoints producing, and consuming messages communicate with the queue rather than one another. Producers don't have to wait for requests to be processed before adding them to the queue. The message can be processed by consumer whenever they are available. The system never has a component wait for another, maximizing the flow of data. 

Using message queues, you can scale exactly where you need to. Multiple instances of your application can all contribute requests to the queue without the worry of a collision when workloads are at their height. You may divide the burden among a fleet of consumers when your queues lengthen due to the incoming requests. Demand may change the size of the queue, the producers, and the customers. 

Benefits of Queuing Solution

Local transactions are supported by Service Bus queues within the framework of a single queue. Service Bus-supported ‘Receive’ and ‘Delete’ mode gives users the option to decrease the number of messaging operations (and related costs) in return for a reduced level of delivery certainty.

Following are three most important benefits Queuing solution comes with: 
1. Decoupling

Messaging queues provide a persistent storage and asynchronous communication and thus the availability of one service does not impact the another. They are eligible to work in a disconnected fashion.

3. Granular Scalability 

Messaging queues helps to achieve granular scalability where the producer or consumer can scale on their own choice without even impacting the other

Azure Service Bus - A managed Queuing system on Azure Cloud

Azure Service bus is a highly scalable service that helps to achieve asynchronous messaging and exchanging data among decoupled systems. Moreover, since it is a Platform as a Service (PaaS) offering from Microsoft, thus, you don’t have to manage the Infrastructure and configuration. Azure cloud manages all this for you. 
Among all others, the most important feature of Azure Service Bus queue is that it guarantees messages to be delivered in FIFO order, which many other queuing solutions fail to provide, even Azure Storage Queues. This makes service bus the most suitable choice than any other Message Queues, though not the only choice. However, Other features to include high availability, auditing, Geo redundancy etc.

Managed Queuing System on Azure Cloud

Asynchronous messaging and data exchange among disconnected systems may be accomplished with the aid of Azure Service Bus, a highly scalable service. You also don't have to handle the infrastructure or setup because it is Messaging as a Service (MaaS) product from Microsoft. All of this is managed by the Azure cloud. 

The fact that Azure Service Bus queues ensure message delivery in FIFO order, which many other queuing systems, including Azure Storage Queues, do not, is the most crucial aspect among the others. Service Bus is the best option among all Message Queues; however, it is not the only one. High availability, auditing, geo-redundancy, and other aspects, nevertheless, are also important. 

Azure Service Bus has three messaging entities: 

1. Message Queues 

Queues permit one-way communication. For the motive of storing dispatched the receiving utility is prepared to get hold of and system them, every queue serves as an intermediary (additionally called a broker). Incoming communications are sorted into queues and given timestamps. Each incoming message is divided into availability zones and kept in triple-redundant storage if the Namespace is zone-enabled. 

2. Publish-Subscribe topics 

Through subscriptions, topics offer one-way conversation. A queue is akin to an Azure Function Service. Bus Although Topic serves as a broker, it enables each subscriber to view just messages that satisfy requirements. In publish/subscribe messaging systems, topics are helpful. You can, at your discretion, specify rules for a subscription as well. A subscription rule applies filters to specify the circumstances for copying the message into the subscription. You may create optional actions to change your message information using them as well.

3. Relays 

Bidirectional communication is provided through relays. A relay does not store in-flight messages it is not a broker unlike queues and topics. Instead, it merely forwards them to the final application. Windows Communication Foundation is used for all communication while utilizing Azure Function Service Bus Relays (WCF).

One more thing before we move ahead to the next important concept is namespace. To describe namespace we must check that all message components Queues, Topics, and Relays are scoped inside a Namespace. Utilizing Azure Service Messaging Services is crucial and one of the primary steps. Numerous Queues and Topics may be found inside a single Namespace, which frequently acts as an application container. Some basis features of Azure Service Bus on Cloud are: 

  • Create dependable and flexible cloud applications using messaging 
  • Make your apps independent of one another. 
  • Protect your application against brief traffic peaks. 
  • Connect your current on-site systems to cloud-based services. 
  • Send messages to several separate back-end systems. 
  • Expand ordered messaging to several readers. 
  • Ensure that current Java Message Service (JMS) applications may communicate with the Service Bus. 

Azure Service Bus Offerings

Tiers of Service Buses with Features. There are two levels of Service Bus features: 

1. Standard Tier 

It may be applied to the first deployment of QA and development environments. Performance at the Standard tier is unpredictable due to inconsistent latency and throughput. The largest message size is limited to 256 kb, and built-in scaling is also not accessible. 

2. Premium Tier 

Production deployments can utilize it. For varying workloads, it offers excellent throughput and auto scalability. The maximum message size is 1 MB. Resource separation at the CPU and memory levels is provided by premium name spaces. When used at full capacity, Premium tier resources perform significantly more quickly than Standard ones.

Azure Service Bus Queues V/s Topics

Queues and Topics are essentially identical, with the difference that topics may have many, independent subscriptions. Each message posted to a Topic can be copied and forwarded to a subscriber of that Topic. A subscription might be assigned to several receivers. A subscription can only belong to one Topic; however, a topic can have zero or more subscriptions. You can use rules to define extra actions to filter or change message characteristics if you don't want all subscribers to view every message: 

1. Queue 

This messaging system can be employed by businesses who view communications as their lifeblood and in more sophisticated messaging infrastructures. Additionally, when the one-to-one model is required for message transmission. 

2. Topic 

This communications model has many Subscriptions layered on top of it. We refer to these as Topic Subscriptions. If it is necessary to convey incoming messages to several people or systems, one can use this approach. A Topic may have nearly 1800-2000 subscribers at a time. 

3. Service Bus Queue and Topic in the Hotel Booking Application 

When a consumer makes a hotel reservation using a web application, the new reservation is added to a service bus queue. The message will be picked up by the Logic App that is listening to the Queue and processed further. Web App and the Logic App are in this instance loosely connected. Due to the fact that the Producer (Web App) and the Consumer (Logic App) do not need to send and receive messages simultaneously, temporal decoupling is achieved. 

The messages are pushed into Service Bus Topic after being processed by the Logic App with the aid of an Azure Function using data gathered by the hotel application. To handle communications that the hotel management accepted and refused, the subject had numerous subscribers. Correlation filters are used by the subscribers to limit the messages they should receive.

Azure Service Bus Architecture

Let unow proceed to understand. Azure Service Bus architecture where we have a foundational grasp of queues, topics, subscriptions, and relays. 

Publisher apps generate messages or information to be communicated and received by receivers. They are the initial step in the communication process. The first level of our azure bus structure consists of web applications that communicate with Queues. Until the receiving application is ready to receive and process messages, they are stored in queues. 

Additionally, a message is transmitted via Azure Function Service Bus Topics. Using subscriptions, Topics can distribute incoming messages to several separate receivers.

Azure Service Bus Tools

Service Bus Explorer 

Users may connect to a Service Bus namespace and easily manage message items using the Service Bus Explorer. The tool offers additional capabilities including the ability to test topics, queues, subscriptions, relay services, notification hubs, and events hubs, as well as the ability to import and export data. 

Choose the namespace you want to send and receive messages from, as well as the specific queue or topic inside that namespace, to use this tool. 

Understanding Azure Service Bus Metrics 

You may view the status of the resources in your Azure subscription using Azure Service Bus metrics. With the help of a comprehensive collection of metrics data, you can evaluate the overall health of your Service Bus resources, not just at the namespace level but also at the entity level. These data are significant since they enable you to keep tabs on Service Bus's condition. Without contacting Azure support, metrics can assist in resolving root-cause problems. 

1. Request Metrics 

Counts the number of data and management operations requests. 

Metric NameDescriptionUnitAggregation TypeDimension 
Incoming RequestsNumber of requests sent to the Service Bus service during a given time frame.CountTotalEntityName (“Azure Service Bus”)
Successful RequestsThe total number of requests that were fulfilled by the Service Bus service during a certain time frame.CountTotalEntityName (“Azure Service Bus”)
Server ErrorsThe number of requests not processed due to an error in the Service Bus service over a specified period.CountTotalEntityName
User Errors:1. Client-side errors (In HTTP that would be 400 errors). 2.Errors that occur while processing messages, such as MessageLockLostExceptionThe number of requests not processed due to user errors over a specified period.CountTotalEntityName
Throttled Requests" The number of queries throttled because the usage limit was exceeded."CountTotalEntityName

 2. Message Metrics 

Metric NameDescriptionUnitAggregation TypeDimension
Incoming MessagesThe total number of events or messages transmitted to Service Bus in a given time frame.CountTotalEntityName
Outgoing Messages
Active Messages
Dead-lettered messages
Scheduled messages

3. Connection Metrics

Metric NameDescriptionUnitAggregation TypeDimension
ActiveConnectionsAn entity's and a namespace's total number of active connections.CountTotalEntityName

4. Error Metrics

Metric NameExportable via diagnostic settingsUnitAggregation typeDescriptionDimensions
Server ErrorsNoCountTotalThe number of requests not processed because of an error in the Service Bus service over a specified period.Entity nameOperation Result
User ErrorsNoCountTotal"Over a certain time period, the number of requests that were not completed due to user mistakes."Entity nameOperation Result

5. Some Important Limits and Quotas

Limit/Quota NameValue
Queue/topic size1,2,3,4, or 5 GB

If partitioning is enabled -80 GB
Number of concurrent connectionsNet Messaging:1,000

AMQP: 5,000
Number of topics/queues per service namespace10,000
Number of partitioned topics/queues per service namespaceBasic and standard Tiers- 100

Premium- 1,000 {per messaging unit]
Message size for a queue/topic

subscription entity
Maximum message size: 256 KB

[Standard tier} I 1 MB (Premier tier).
Number of subscriptions per topic


Advanced Features of Azure Service Bus

Advanced capabilities in Service Bus allow you to address more complicated communications difficulties. Several of these traits are described below: 

1. Message Sessions 

Use sessions to ensure first-in, first-out (FIFO) in Service Bus. Message sessions provide for the exclusive, ordered treatment of unlimited sequences of linked communications. The session feature also enables the storage of session state, which allows sessions to securely transfer across handlers in high-scale, high-availability applications. 

2. Auto Forwarding 

The auto forwarding function links a queue, subscription, or topic to another queue, subscription, or subject inside the same namespace. When you take advantage of this functionality, Service Bus instantly transfers messages from one subscription or queue to another. All these actions are transactional. 

3. Dead Letter Queue 

Dead-letter queues are connected to all Service Bus queues and topics (DLQ). Messages that fit the following description are stored in a DLQ: 

  • They cannot be effectively conveyed to any receiver. 
  • The timer expired. 
  • The receiving application specifically excludes them from its scope. 
  • The rationale for placing messages in the dead-letter queue is documented on each message. The dead-letter queue functions similarly to any other queue except from its unique endpoint. A DLQ can be browsed by a program or tool, or it can be dequeued from. A dead-letter queue can also be auto forwarded out of. 

4. Disaster Recovery 

The disaster recovery feature allows message processing to carry on in another region or data center if an Azure region goes down. In addition to allowing the namespace identity to transition to the secondary namespace, the functionality preserves a structural mirror of a namespace accessible in the secondary area. Once the availability episode has passed, the already-posted messages are still available for recovery in the previous primary namespace. 

5. Security 

Standard HTTPS or REST protocols and their corresponding security features, such as transport-level security, are supported by Service Bus (TLS). Using Azure Active Directory role-based security or Shared Access Signature, clients can be given access authorization. 

Service Bus offers security features including an IP firewall and virtual network integration to guard against unauthorized traffic. 

6. Duplicate Detection 

The broker can drop a probable duplicate and the sender can transmit the identical message again thanks to the duplication detection mechanism. 

7. Message Deferral 

A received message may be delayed in retrieval by a queue or subscription client. The message could have been sent against the client's expectations; therefore, the client wishes to hold off until it gets another message. Deferred messages are still in the queue or subscription and need to be manually revived using the sequence number that was issued by the service. 

8. Scheduled Delivery 

You may specify a deadline for when messages will be ready for consumption by adding them to a queue or topic for delayed processing. Additionally, scheduled communications can be stopped. 

9. Auto Delete on Idle 

You can set an idle period after which a queue or topic subscription should be automatically terminated with autodelete on idle. When there is activity on the object, the interval is reset. Five minutes is the bare minimum. 

10. Transactions 

A transaction creates an execution scope by combining two or more activities. You can combine activities against many communications entities within the purview of a single transaction using Service Bus. Message entities can be subscriptions, topics, or queues. 

11. Supporting Ordering 

You may decide whether messages posted to a subject will be delivered to the subscriber in the same order they were sent by using the Support ordering function. Partitioned subjects are not supported by this functionality. 

All the advanced features of Azure Bus Service are well known to a solution architect. To become a solution architect, enroll in KnowledgeHut’s Solutions Architect Associate course. 

Azure Service Bus Messages 

  • Message Body: Data that exists. 
  • Metadata: To interpret message correct metadata is used. 

The sole purpose of creating and sending a message is data. This data is called a Message body that will act as a bridge in sending and receiving message. 

It is necessary to transmit message metadata, a supplemental piece of information that might comprise message attributes or headers, for the recipient to correctly comprehend the message. Service There are two sets of attributes in a bus message. The system has already specified the broker's properties. The application can define and change the key-value pairs that make up the user properties. 

Messages are handled using Microsoft Azure Service Bus. A payload and metadata are carried by messages. The information, which takes the form of key-value pair attributes, specifies the payload, and provides Service Bus and applications with handling guidelines. Sometimes the information the sender intends to convey to the recipients can be carried by the metadata alone, leaving the payload empty. 


A dependable, fast, and secure foundation for application communication is provided by Azure Service Bus. The Service Bus may execute intricate workflows, but it can also operate more smoothly even under varying loads thanks to interaction with Azure SQL Database, Azure Storage, and Web Apps. 

Organizations must develop a Single Source of Truth (SSOT) and Real-time Data Migration capabilities between applications in the same way that having a dependable and fault-tolerant communications environment is essential. 

We thought that this post would make it easier for you to understand the services provided by Microsoft Azure. Try KnowledgeHut’s Cloud Computing certification if you wish to learn more about cloud - based solutions and get certified. 

Frequently Asked Questions (FAQs)

1. Where is Azure Service Bus used? 

A cloud messaging service called Azure Service Bus is used to link any cloud-based software, hardware, and services to other software or services. As a result, it serves as the communications foundation for cloud-based or cross-platform applications. 

2. How do I communicate with Azure Service Bus? 

Right-click on the queue or topic name in the Service Bus Explorer navigation pane and choose "Send Messages" to send a message to that queue or topic. Service Bus serves as a message service between two parts of a business processConnecting to the Service Bus for integration applications is simpler with Logic Apps. All you need to do is utilize a connector to push messages to other components. 

3. How do you implement Azure Service Bus in .NET? 

With the help of the Azure portal, create a Service Bus namespace. Make a Service Bus queue using the Azure portal. Create a terminal application for.NET Core to deliver a series of messages to the queue. To get such messages from the queue, create a terminal application in.NET Core. 


Gagan Baheti


Gagan Baheti, a Google Cloud Professional Architect working as a SAP Consultant at IBM for Heineken with more than 2 years of experience in IT and have experience in architecting cloud solution, developing highly scalable PaaS solutions using both Azure and GCP. I am author of multiple blogs that talks about latest technologies and solutions to challenges faced by cloud developers.I have worked on a lot of domains including MEAN Stack, SAP and Cloud.

Share This Article
Ready to Master the Skills that Drive Your Career?

Avail your free 1:1 mentorship session.

Your Message (Optional)

Upcoming Cloud Computing Batches & Dates

NameDateFeeKnow more
Course advisor icon
Course Advisor