PubSub+ Cache
Solace PubSub+ Cache is a scalable, in-memory message cache for Direct messaging. It allows client applications connecting to PubSub+ event brokers to request the most current messages for a topic of interest when they come online, or when they start subscribing to topics that they were not originally subscribed to. For example, a real-time stock quote display may need to retrieve the latest value for a symbol when a user expresses interest in monitoring that symbol. In such a situation, it is useful to have a standalone application that saves the last messages sent for a topic of interest, and responds to client requests for copies of the messages published to that topic.
To provide real-time delivery of messages, PubSub+ Cache utilizes the event broker message bus to cache live data messages according to topic subscriptions and deliver cached messages for corresponding topics that are specified in client requests. The message bus load balances client requests for messages amongst a group of message caches (PubSub+ Cache Instances) hosted on Linux computer platforms. This group of PubSub+ Cache Instances (a Cache Cluster) is configured to listen for a common set of topics published to a specific Message VPN. When published messages match the topic subscriptions for the Cache Cluster, the PubSub+ Cache Instances cache those live data messages. Client cache requests for messages matching those topics can then be serviced by any of the Cache Instances within the Cache Cluster. Clients can request a particular number of cached messages or messages that are no older than a specific time.
Client cache requests for messages matching those topics can then be serviced by any of the Cache Instances within the Cache Cluster. Clients can request a particular number of cached messages or messages that are no older than a specific time. For more information, see Using PubSub+ Messaging APIs with PubSub+ Cache.
System Requirements
The following are required to operate PubSub+ Cache.
Server
Linux x86 64-bit (x86_64) server
Cores
- Minimum: Two cores
- For high-performance use-cases without plug-in: Four cores are recommended
- For high-performance use-cases with plug-in: Five or six cores are recommended
Minimum Versions of PubSub+ Components Required for PubSub+ Cache
PubSub+ Cache supports the following component versions:
| Component Description | Minimum Version |
|---|---|
|
PubSub+ appliances |
9.7 |
|
PubSub+ software event brokers |
9.7 |
|
Linux computer platforms |
Linux (x86_64) variants that are in active support and have security patches. |
Upgrading PubSub+ Cache
To upgrade your PubSub+ Cache instance, see Upgrading PubSub+ Cache.