Configuring Multi-Site (WAN) Event Queues
In a multi-site (WAN) installation, GemFire uses gateway sender queues to distribute events for regions that are configured with a gateway sender. AsyncEventListeners also use an asynchronous event queue to distribute events for configured regions. This section describes additional options for configuring the event queues that are used by gateway senders or AsyncEventListener implementations.
Before you begin, set up your multi-site (WAN) installation or configure asynchronous event queues and AsyncEventListener implementations. See Configuring a Multi-site (WAN) System or Implementing an AsyncEventListener for Write-Behind Cache Event Handling.
You can configure a gateway sender queue or an asynchronous event queue to persist data to disk similar to the way in which replicated regions are persisted.
By default, GemFire uses multiple dispatcher threads to process region events simultaneously in a gateway sender queue for distribution between sites, or in an asynchronous event queue for distributing events for write-behind caching. With serial queues, you can also configure the ordering policy for dispatching those events.
Conflating a queue improves distribution performance. When conflation is enabled, only the latest queued value is sent for a particular key.