On customer-hosted runtime plane, where are persistent queues stored for standalone runtimes and for clusters?

• A. Standalone Mule runtimes persistent queues are stored on local disk; cluster deployments persistent queues are backed by the cluster's distributed data grid
• B. Standalone Mule runtimes persistent queues are stored on cloud storage; cluster deployments persistent queues are backed by local disk
• C. Standalone Mule runtimes persistent queues are stored in memory; cluster deployments persistent queues are stored in a database
• D. Standalone Mule runtimes use an external JMS broker; cluster deployments use JMS

Answer: (A)

The main idea here is how persistent queues are stored in a customer-hosted (on-prem) runtime plane, depending on whether you’re running a single standalone instance or a cluster. For a standalone Mule runtime, the persistent queues are written to the local disk of that machine. This provides durability for the queue across restarts without needing external services. In a cluster, the queues aren’t kept on one node’s disk; they’re backed by the cluster’s distributed data grid. That means the queue data is stored across the cluster, enabling replication, fault tolerance, and high availability so messages can be consumed even if individual nodes fail.

Other patterns like cloud storage, in-memory storage, a database, or using an external JMS broker would involve different architectures or dependencies that don’t align with how persistent queues are implemented in the on-prem, single-node versus clustered runtime plane.