Considerations for Implementing Global Caching

To implement PubSub+ Cache service with Global Caching, follow the general configuration steps to set up basic PubSub+ Cache service for a Distributed Cache (refer to Steps to Configure PubSub+ Cache), but be sure to make the following special configuration considerations:

Networking Considerations

To use Global Caching, an administrator must explicitly configure the routing links between event broker neighbors in the messaging network so that they can exchange topology and subscription information using the Content-based Shortest Path First (CSPF) protocol and Subscription Management Routing Protocol (SMRP). Routing links are required so that published Direct messages can be exchanged between neighbors on their way to the final set of destination subscriber clients.

For information, refer to and Multi-Node Routing.

Message VPN Considerations

  • All Distributed Caches must use the same Message VPN that publishing and consuming clients connect to.
  • The export subscriptions policy must be enabled within a Message VPN so that a local PubSub+ Cache Instance can receive messages from a home Cache Cluster provisioned on another event broker. (Refer to Enabling Subscription Export.)
  • Each PubSub+ Cache component (Distributed Caches, Cache Clusters, PubSub+ Cache Instances) in the Message VPN must be given a unique name. Those names are used to form topic subscriptions, which are used by the Solace messaging APIs and the router to communicate with the various PubSub+ Cache components.

Cache Cluster Considerations

  • When configuring each Cache Cluster in a Distributed Cache, be sure to configure the Global Caching-specific parameters for that Cache Cluster. Refer to Configuring Global Caching for a Cache Cluster.
  • Global Caching must be enabled for all local and home Cache Clusters. Even if a Cache Cluster only acts as a local cache and never requests global data from a remote Cache Cluster, it must have global caching enabled to publish global cache heartbeats.
  • The local Cache Clusters and home Cache Clusters must be in different Distributed Caches.

PubSub+ Cache Instance Considerations

When customizing copies of the provided configuration file (sampleConfig.txt), which is required to provide each PubSub+ Cache Instance with configuration parameters on their initial invocation (refer to Steps to Configure PubSub+ Cache), review and modify, if required, the Global Caching parameters.