What kind of queues are typically faster but less reliable?

Transient queues are designed for scenarios where speed and performance are prioritized over data persistence. They are typically stored in memory rather than on disk, enabling quicker access and processing times. This makes transient queues suitable for applications where the data is ephemeral, meaning that if the system goes down or the data is lost, it is not catastrophic for the application or the business process.

In contrast, persistent queues, as the name suggests, focus on reliability and durability, ensuring that messages are not lost even if the system fails. External queues may refer to integrations with other queueing systems or message brokers, but they don’t inherently classify the speed versus reliability aspect. JMS (Java Message Service) queues can be configured to be either persistent or transient, depending on the implementation.

Thus, in use cases where high throughput is essential and some risk of message loss is acceptable, transient queues provide a valuable solution.