Global Event Configuration
hazelcast.event.queue.capacity: default value is 1000000
hazelcast.event.queue.timeout.millis: default value is 250
hazelcast.event.thread.count: default value is 5
A striped executor in each cluster member controls and dispatches the received events. This striped executor also guarantees the event order. For all events in Hazelcast, the order in which events are generated and the order in which they are published are guaranteed for given keys. For map and multimap, the order is preserved for the operations on the same key of the entry. For list, set, topic and queue, the order is preserved for events on that instance of the distributed data structure.
To achieve the order guarantee, you make only one thread responsible
for a particular set of events (entry events of a key in a map, item
events of a collection, etc.) in
If the event queue reaches its capacity (
and the last item cannot be put into the event queue for the period
hazelcast.event.queue.timeout.millis, these events are
dropped with a warning message, such as "EventQueue overloaded".
If event listeners perform a computation that takes a long time, the
event queue can reach its maximum capacity and lose events. For map
and multimap, you can configure
hazelcast.event.thread.count to a
higher value so that fewer collisions occur for keys, and therefore
worker threads do not block each other in
StripedExecutor. For list, set,
topic and queue, you should offload heavy work to another thread.
To preserve order guarantee, you should implement similar logic with
StripedExecutor in the offloaded thread pool.