Mastering Spring Cloud

Consumer groups

Our purpose is clear. We have many microservices that consume messages from the same topic. Different instances of an application are placed in a competing consumer relationship, but only one of them should handle a given message. Spring Cloud Stream introduces the concept of a consumer group that models this behavior. To activate such a behavior, we should set a property called spring.cloud.stream.bindings.<channelName>.group, with a group name. After setting it, all groups that subscribe to a given destination receive a copy of the published data, but only one member of each group receives and handles a message from that destination. In our case, there are two groups. First, for all the account-service instances with a name ...