A processor with a bounded FIFO (First-In, First-Out) queue channel is the correct choice. It inherently preserves the order of events as they pass through. The ‘bounded’ aspect is key for back-pressure; when the queue reaches its capacity, it signals upstream components to slow down, preventing system overload and event loss during bursts, which aligns perfectly with the requirement.

The element is used to declaratively wire event listeners. In this context, with the ‘ref’ pointing to ‘myBean’, it means that the ‘myBean’ component (which must implement the EventListener interface) is being registered to receive event notifications sent *from* this processor. The processor is the source, and myBean is the listener.

The clause ‘PARTITION BY symbol RANGE INTERVAL ‘5’ MINUTE’ is correct. ‘PARTITION BY symbol’ ensures the moving average is calculated per stock symbol independently. ‘RANGE INTERVAL ‘5’ MINUTE’ defines a sliding window that looks back 5 minutes from the current event. Because it’s a sliding window attached to the event stream itself, a new result is generated only when a new trade (event) arrives, meeting the requirement of not using a fixed time tick.

For events to flow from a channel to a component, that component must be registered as a listener on that channel. If the processor is not declared as a listener (e.g., via a element within the channel definition or via annotation in the processor bean), it will not receive the events published to that channel, causing the observed ‘disappearance.’ The event-type property is for schema, not routing.

The ‘MAX’ or ‘DEFAULT’ subclause within the PARTITION BY statement is designed for this exact scenario. For example, ‘PARTITION BY userId MAX 1000’ limits the system to maintaining state for only 1000 partitions at a time. If a 1001st unique userId arrives, the system will evict one of the existing partitions (often the least recently used) based on the specified policy, preventing memory exhaustion and performance degradation.

The standard and most efficient method is to inject the Coherence NamedCache (obtained via a CacheFactory) as a property of your processor bean. Within the processor’s `process()` method, you can then synchronously call `cache.get(event.getCustomerId())` to perform the lookup. This leverages in-memory speed and is the pattern demonstrated in OEP documentation for cache-based enrichment.

The key is the ‘SLIDE 30 SECONDS’ interval. This creates a *tumbling* window that evaluates and emits results on a fixed time schedule, independent of event arrival. The window looks back over the last 1 minute (RANGE), but the query computation and output are triggered every 30 seconds by the slide interval. Therefore, results are produced periodically every 30 seconds.

While CQL is powerful for stream-based filtering, aggregation, and pattern matching, embedding complex procedural logic and external calls into a single query makes the application difficult to understand, test, and modify. Breaking the flow into discrete processors (e.g., one for filtering, one for enrichment, one for business rules) follows the principle of separation of concerns. This makes each component simpler, easier to unit test, and allows for independent debugging and modification.

The HTTP pub-sub adapter uses a long-polling mechanism. To prevent client connections from being timed out by intervening networks, proxies, or load balancers during idle periods, it sends periodic heartbeat messages. If the `heartbeat-interval` is disabled or set to a value longer than the timeout of an intermediate network device, the connection may be dropped, causing clients to stop receiving updates. This is a common issue in real-world deployments.

A processor with a bounded FIFO (First-In, First-Out) queue channel is the correct choice. It inherently preserves the order of events as they pass through. The ‘bounded’ aspect is key for back-pressure; when the queue reaches its capacity, it signals upstream components to slow down, preventing system overload and event loss during bursts, which aligns perfectly with the requirement.0