Hi @davidm,
The brokers support configuration for a last value cache product called PubSub+ Cache, this is the configuration options your are seeing. In addition to the configuration inside the broker, you will need to configure and run caches outside the broker and they will have to be purchased separately. You can run those caches on any standard linux server.
You can find an overview of the PubSub+ Cache product here:
The configuration of a cache instance (running on linux) is fairly simple and is mainly consisting of connection information for the cache instance to connect to a Solace broker. All the rest is then configured in the broker and consists of (high level):
- a cache, which consists of one or multiple cache clusters
- cache clusters, which consists of multiple cache instances (for HA)
The home cache cluster configuration is only required, if you have distributed caches (e.g. in different regions) caching different parts of your topic hierarchy - this is referred to as global caching in our documentation. A typical example from the market data world would be a New York cache cluster caching US market data and a London cache cluster caching UK/Europe market data. You can configure the London cache cluster with the information about what the NY cache cluster is caching, so that clients requesting NY data in London don’t need to connect to NY brokers/caches and can just ask the London caches to get the data from the NY caches for them (the brokers need to be meshed via DMR or MNR for this to work).
Hope this is enough information to get you started.
p.s. If using MQTT for all your clients is an option for you, you may want to look into using the MQTT retain feature as an alternative.