How to configure gemfire as message store for aggregator module in spring cloud data flow

Question

Link - https://github.com/spring-cloud-stream-app-starters/aggregator/tree/master/spring-cloud-starter-stream-processor-aggregator does not list property for gemfire message store

Answer 1

The GemfireMessageStore is configured like this:

@ConditionalOnClass(GemfireMessageStore.class)
@ConditionalOnProperty(prefix = AggregatorProperties.PREFIX,
        name = "message-store-type",
        havingValue = AggregatorProperties.MessageStoreType.GEMFIRE)
@Import(ClientCacheAutoConfiguration.class)
static class Gemfire {

    @Bean
    @ConditionalOnMissingBean
    public ClientRegionFactoryBean<?, ?> gemfireRegion(GemFireCache cache, AggregatorProperties properties) {
        ClientRegionFactoryBean<?, ?> clientRegionFactoryBean = new ClientRegionFactoryBean<>();
        clientRegionFactoryBean.setCache(cache);
        clientRegionFactoryBean.setName(properties.getMessageStoreEntity());
        return clientRegionFactoryBean;
    }

    @Bean
    public MessageGroupStore messageStore(Region<Object, Object> region) {
        return new GemfireMessageStore(region);
    }

}

The point is that you always can override that ClientRegionFactoryBean with your own. Or you can take into account that ClientCacheAutoConfiguration is based on the @ClientCacheApplication, which, in turn, allows you to have a ClientCacheConfigurer bean and provide whatever is sufficient for your client cache configuration. Including config and pool. That's right: it is not on the app starter configuration level and you have to right some custom code to be included as a dependency into the final uber jar for target binder-specific application.

More info how to build them is here in Docs: https://docs.spring.io/spring-cloud-stream-app-starters/docs/Einstein.RC1/reference/htmlsingle/#_patching_pre_built_applications