Node client for eventsgateway server.
npm install eventsgateway-client-node
Compatible with node 6+
const EventsGatewayClient = require('eventsgateway-client-node')
// config containing grpc server address and kafka topic
const config = {
"producer": {
"async": true, // if you want to use the async or sync dispatch
"maxRetries": 3, // (async-only) how many times to retry a dispatch if it fails
"retryIntervalMs": 1000, // (async-only) first wait time before a retry, formula => 2^retryNumber * retryInterval
"batchSize": 10, // (async-only) maximum number of messages to send in a batch
"lingerIntervalMs": 500, // (async-only) // how long to wait before sending messages, in the hopes of filling the batch
"waitIntervalMs": 1000 // polling interval to check whether all events were sent before shutting down
},
"grpc": {
"serveraddress": "localhost:9999",
"timeout": 500
},
"kafkatopic": "default-topic" // default topic to send messages
}
// initialize the client
const eventsgatewayclient = new EventsGatewayClient(config)
// send event to configured topic
// calls should be wrapped in a try/catch
try {
// async client, no need to await
this.app.eventsGatewayClient.send('pingEvent', { some: 'value' })
// sync client, block if you want to handle errors
await this.app.eventsGatewayClient.send('pingEvent', { some: 'value' })
} catch (err) {
// no need to log here, eventsGateway already logs failures
}
// send event to custom topic
try {
// no need to `await` async send, if you're using sync client, use `await`
// as well, and handle failures
// async client, no need to await
this.app.eventsGatewayClient.sendToTopic('pingEvent', 'my-topic', { some: 'value' })
// sync client, block if you want to handle errors
await this.app.eventsGatewayClient.sendToTopic('pingEvent', 'my-topic', { some: 'value' })
} catch (err) {}Response time, success and error counters are exposed in a koa app.
// Prometheus metrics endpoint
// available at localhost:$EVENTSGATEWAY_PROMETHEUS_PORT
// defaults to localhost:9090
eventsgatewayclient.metrics.prometheus.listen() // blocking!