Microgateways allow Solace PubSub+ event brokers to act as HTTP load balancers, or simple API gateways between RESTful API clients and RESTful API service providers. When a Microgateway is configured, you can use request/reply semantics to send REST requests from clients through the event broker to the service providers responsible for servicing the requests, and return the responses back to the requesting clients. In other words, the event broker acts as an intermediary for those applications, enabling them to use the REST request/reply mechanism to reach remote microservices.

For a description of the various use cases that are enabled through the Microgateway feature, refer to Microgateway Use Cases.

Introductory Video

The following video introduces the Microgateway feature.

Brief video illustrating the completion of the surrounding steps.

When to Use a Microgateway Versus a REST Messaging Service

Within a Message VPN, you can deploy either a Microgateway or a REST messaging service, but not both.

You Should Use a Microgateway When

You want to provide connectivity between a RESTful service endpoint (defined by Swagger/Open API, RAML, or more informally) and a REST client. Microgateways provide higher performance, but less functionality than API Gateways, yet more capabilities than HTTP load balancers. When a Microgateway is deployed, Solace imposes no requirements on the HTTP protocol used.

For information describing how to configure a Microgateway, refer to Microgateway Configuration.

You Should Use a REST Messaging Service When

You want an application to send and/or receive messages, but would prefer to use HTTP libraries instead of MQTT, AMQP, or libraries from Solace. When a REST messaging service is deployed, your application must use HTTP as defined in Solace REST HTTP Message Encoding.

For more information about REST messaging, refer to REST.

Comparison Between Microgateways and Other Gateway Products

Solace Microgateways are not intended be used as generic load balancers between browser and server applications. They provide high performance, simplicity, and enable event driven architectures for RESTful services. More specifically, they provide a unique function between the capabilities of an API Gateway and the simplicity of an HTTP load balancer.

The following table outlines some of the functional differences between API gateways, Solace Microgateways, and HTTP load balancers.

Capability API Gateway Solace Microgateway HTTP Load Balancer
Authentication checkmark-16 checkmark-16  
Authorization checkmark-16 checkmark-16  
Deep (Payload-based) Authorization checkmark-16    
Orchestration checkmark-16    
Request Load Balancing to Consumers   checkmark-16 checkmark-16
Request Prioritization   checkmark-16  
Request Burst Absorption and Buffering   checkmark-16  
Pub/Sub Eventing   checkmark-16  
Multi-Protocol Message Delivery   checkmark-16