Advanced Event Client
Clean Starting Event Client Proxy
EventClient setup will generally fail if the underlying transport is not available.
cleanStartingProxyEventClient exists to allow your application to start up even if the underlying event client fails.
If replaces the event client with a no-op proxy that will fail all emit calls, but otherwise setup Views, Adapters and Sagas correctly.
It will then periodically attempt to recreate the event client until it succeeds. Once that occurs, all the pending subscriptions are attached to it and the system will become live.
import {setEventClient, eventClientOnKafka} from "@eventicle/eventiclejs";
import {cleanStartingProxyEventClient} from "@eventicle/eventiclejs/dist/events/core/cleanStartingProxyEventClient";
// .. other setups
setEventClient(await cleanStartingProxyEventClient(() => eventClientOnKafka(kafkaConfig)));Kill Switches/ Disconnect Event Client
In some cases, you may need to forcefully disconnect your application from the event infrastructure, while leaving it running. For example, during Kafka broker recreation.
This is supported by calling eventClient().shutdown()
Once the kill switch has been activated, it is not currently possible to reconnect without full recreation of the eventClient. Shutdown/ recreate is not a behaviour that is well tested, and so it is recommended to restart your application in this case.
import {setEventClient, eventClientOnKafka} from "@eventicle/eventiclejs";
import {cleanStartingProxyEventClient} from "@eventicle/eventiclejs/dist/events/core/cleanStartingProxyEventClient";
// .. other setups
setEventClient(await cleanStartingProxyEventClient(() => eventClientOnKafka(kafkaConfig)));
// app runs
await eventClient().shutdown()
let health: KafkaClientHealth = getKafkaClientHealth()
health.healthy === false
health.producer.status === "disconnected"
await eventClient().emit( ... ) (1)| 1 | This will now always throw an error - "Kill Switch Thrown" |