The subscription mode is used to control the rate of events received by the subscriber.

Terminology:

Tick: Refers to the exact clock tick Interval: Refers to the duration between two ticks

Parameter mode can have two values -

- SubscriptionModes.RateAdapterMode - SubscriptionModes.RateLimiterMode

These two modes can be accessed in Java as:

- SubscriptionModes.jRateAdapterMode - SubscriptionModes.jRateLimiterMode

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                   |                 Rate Adapter                  |                 Rate Limiter
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                   |                                               |
1. Description     | Ensures that the subscriber will receive an   | Ensures that events will be delivered as soon
                   | event exactly at each tick.                   | as they are published along with the guarantee
                   |                                               | that no more than one event is delivered within
                   |                                               | a given interval.
                   |                                               |
2. Fast Publisher  | The subscriber receives the most recently     | The subscriber receives the event as soon as it
                   | published event at each tick.                 | is published during the interval.
                   |                                               |
                   | Some events will be dropped because of the    | Some events will be dropped because of the
                   | guarantee that exactly one event is received  | guarantee that at most one event is received
                   | at each tick.                                 | within an interval.
                   |                                               |
3. Slow Publisher  | The subscriber will get the last published    | The subscriber will not receive events at some
                   | event on each interval.                       | intervals.
                   |                                               |
                   | The subscriber will receive duplicate events  | The subscriber will never receive duplicate
                   | in case no element is published during that   | events.
                   | interval.                                     |
                   |                                               |
4. Use cases       | The synchronized event stream received on     | When there is no strict requirement of
                   | subscription can be used as clock ticks by a  | synchronization of received events with the
                   | component to perform other arbitrary tasks.   | clock tick and minimum latency is required.
                   |                                               |
5. Trade offs      | Latency of events received in this mode will  | The events received will not be in
                   | be more than that in                          | synchronization with the subscription frequency.
                   | [[SubscriptionModes.RateLimiterMode]].        |
                   |                                               | Some intervals might not receive an event.
                   |                                               |
                   |                                               | Duration observed between events received might
                   |                                               | not match with the specified subscription rate.
                   |                                               |