Overview of the Azure Service Bus emulator
The Azure Service Bus emulator offers a local development experience for the Service bus service. You can use the emulator to develop and test code against the service in isolation, free from cloud interference.
Benefits
The primary advantages of using the emulator are:
- Local development: The emulator provides a local development experience, so you can work offline and avoid network latency.
- Cost efficiency: With the emulator, you can test your applications without incurring any cloud usage costs.
- Isolated testing environment: You can test your code in isolation, to help ensure that other activities in the cloud don't affect the tests.
- Optimized inner development loop: You can use the emulator to quickly prototype and test your applications before deploying them to the cloud.
Note
The Service bus emulator is available under the Microsoft Software License Terms.
Service Bus emulator isn't compatible with the community owned open source Service Bus Explorer
Features
The emulator provides these features:
- Containerized deployment: It runs as a Docker container (Linux based).
- Cross-platform compatibility: You can use it on any platform, including Windows, macOS, and Linux.
- Configurability: You can manage the number of Service bus entities by using the JSON supplied configuration.
- Streaming support: It supports streaming messages by using the Advanced Message Queuing Protocol (AMQP).
- Observability: It provides observability features, including console and file logging.
Known limitations
The current version of the emulator has the following limitations:
- It can't stream messages by using the JMS protocol.
- Partitioned entities aren't compatible with emulator.
- It doesn't support on-the-fly management operations through a client-side SDK.
Note
After a container restart, data and entities don't persist in the emulator.
Differences from the cloud service
Because the Service bus emulator is meant only for development and test purposes, there are functional differences between the emulator and the cloud service.
The emulator doesn't support these high-level features:
- Azure features like virtual network integration, Microsoft Entra ID integration, activity logs, and a UI portal
- Autoscale capabilities
- Geo-disaster recovery capabilities
- Large messages support
- Visual metrics and alerts
Note
The emulator is intended solely for development and test scenarios. We discourage any kind of production use. We don't provide any official support for the emulator.
Report any problems or suggestions in the emulator's GitHub installer repository.
Usage quotas
Like the Service bus cloud service, the emulator provides the following quotas for usage:
| Property | Maximum Value | User configurable within limits |
|---|---|---|
| Number of supported namespaces | 1 | No |
| Number of entities(queues/topics) in a namespace | 50 | Yes |
| Number of Subscriptions per topic | 50 | Yes |
| Number of correlation filters per topic | 1000 | Yes |
| Number of concurrent connections to namespace | 10 | Yes |
| Number of concurrent receive requests on entity (queue/Topic) or subscription entity | 200 | Yes |
| Message size | 256 KB | No |
| Queue or topic size | 100 MB | No |
| Message Time to Live | 1hr | Yes |
Quota configuration changes
By default, the emulator runs with the config.json configuration file. You can configure the quotas associated with Service bus by editing this file in the following ways, based on your needs:
- Entities: You can add more Service bus entities in accordance with the supported quotas.
- Logging: The emulator supports logging on a console, in a file, or both. You can choose according to your personal preference.
Important
You must supply any changes in JSON configuration before you run the emulator. Changes aren't honored on the fly. For changes to take effect, you must restart the container.
You can't rename the preset namespace (name) in the configuration file.
Logs for debugging
During testing, console or file logs help you debug unexpected failures. To review the logs:
- Console logs: On the Docker desktop UI, select the container name.
- File logs: In the container, go to /home/app/EmulatorLogs.