Solace Cache in Pubsub+ Configuration Help

davidm

I'd like to set up a last-value cache with our test cluster in PubSub+. There is a 'Caches' page under 'Advanced Messaging', but I've not managed to work out the relationship between distributed caches, cache clusters, cache instances and home cache clusters.
Can anyone point me at any documentation that would help me?
My aim is to have a SolCache equivalent which I can use from the Solace C API, initialised by passing the appropriate cache name to solClient_session_createCacheSession.

ChristianHoltfurth

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:
https://docs.solace.com/Solace-PubSub-Cache/PubSub-Cache-Overview.htm

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.

davidm

Thanks, Christian. Just to check that I'm understanding correctly, as you saying that SolCache itself it _not _available within the PubSub+ Cloud platform, but can only be deployed on-premises on a Linux server?

ChristianHoltfurth

Hi David, that's right. At least it's not being offered as a full SaaS solution yet.
You could ask your Solace Cloud Support to enable the feature for you and connect your own PubSub+ Cache instances (running in your public or private cloud account) to a Solace Cloud instance, if you want to run it in the cloud (broker SaaS, caches non-SaaS). I believe that could be supported.
But yeah, fully on-prem (or better non-SaaS, because you could operate all of this yourself in cloud) is definitely the more common deployment option with PubSub+ Cache at the moment.

davidm

Thanks again, Christian - that's very helpful.