Service Bus topics and subscriptions in Azure - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

How does message filtering work in Service Bus subscriptions?

You have a Service Bus topic with multiple subscriptions. Each subscription has a filter rule defined. What happens when a message is sent to the topic?

A The message is delivered randomly to one subscription.

B The message is delivered only to subscriptions whose filter rules match the message properties.

C The message is delivered to the first subscription that matches the filter and then stops.

D The message is delivered to all subscriptions regardless of filters.

💡 Hint

Think about how filters help route messages to interested subscribers.

Service Bus topic subscriptions use filter rules to decide which messages they receive. Only subscriptions with filters matching the message properties get the message.

❓ Architecture

intermediate

Choosing between queues and topics in Azure Service Bus

You want to design a messaging system where multiple independent services receive the same messages for processing. Which Azure Service Bus entity should you use?

A Use a single subscription on a topic and share it among all services.

B Use a queue because it supports multiple consumers receiving the same message.

C Use multiple queues, one per service, and send messages to each queue separately.

D Use a topic with multiple subscriptions so each service gets a copy of the message.

💡 Hint

Think about how to broadcast messages to multiple receivers.

Topics with multiple subscriptions allow broadcasting messages to multiple independent consumers. Queues deliver each message to only one consumer.

❓ security

advanced

Securing access to Service Bus topics and subscriptions

You want to restrict a service so it can only send messages to a topic but cannot receive from any subscription. How do you configure Azure Service Bus access policies?

A Create a Shared Access Policy with Send permission on the topic only.

B Create a Shared Access Policy with Listen permission on all subscriptions.

C Create a Shared Access Policy with Manage permission on the topic and subscriptions.

D Create a Shared Access Policy with Send and Listen permissions on the topic.

💡 Hint

Consider the difference between Send and Listen permissions.

Send permission allows sending messages to the topic. Listen permission is needed to receive messages from subscriptions. Manage includes both and more.

❓ Configuration

advanced

Dead-lettering behavior in Service Bus subscriptions

What happens when a message in a subscription exceeds the maximum delivery count?

A The message is moved to the subscription's dead-letter queue for later inspection.

B The message is sent back to the topic for reprocessing.

C The message is automatically deleted from the subscription.

D The message is delivered to all other subscriptions.

💡 Hint

Think about how Service Bus handles messages that cannot be processed successfully.

When a message exceeds the max delivery count, Service Bus moves it to the dead-letter queue of the subscription for troubleshooting or manual handling.

✅ Best Practice

expert

Optimizing throughput with Service Bus topics and subscriptions

You have a high-volume messaging system using Service Bus topics and subscriptions. To maximize throughput and avoid bottlenecks, which approach is best?

A Use a single subscription with multiple competing consumers to process messages in parallel.

B Use a single queue instead of topics to simplify processing.

C Use multiple subscriptions with filters and scale out consumers per subscription.

D Use topics with sessions enabled to guarantee message order across all subscriptions.

💡 Hint

Consider how to distribute load and filter messages efficiently.

Multiple subscriptions with filters allow parallel processing and targeted message delivery. Scaling consumers per subscription improves throughput. Single subscription limits parallelism. Sessions add ordering but can reduce throughput.