Event batching

The Full Stack React Native SDK lets you batch events and includes options to set a maximum batch size and flush interval timeout. The benefit of event batching is less network traffic for the same number of impression and conversion events tracked. By default, event batching is enabled in React SDK.

The event batching functionality works by processing impression events from OptimizelyExperiment or OptimizelyFeature, and conversion events from calling track on the client instance, placing them into a queue. The queue is drained when it either reaches its maximum size limit or when the flush interval is triggered.

The event batching functionality provides support for asynchronous, offline event batching in React Native applications. The events dispatched while the device was offline are stored in a persistent cache on user's device. The failed events are then re-dispatched when:

• Internet connectivity is restored.
• A new event is ready to be dispatched.
• SDK is initialized the next time.

📘

Note

Event batching works with both out-of-the-box and custom event dispatchers.

The event batching process does not remove any personally identifiable information (PII) from events. You must still ensure that you are not sending any unnecessary PII to Optimizely.

Configure event batching

We provide three options to configure event batching: eventBatchSize , eventFlushInterval and eventMaxQueueSize. You can pass in all the options during client creation. Events are held in a queue until either:

• The number of events reaches the defined eventBatchSize.
• The oldest event has been in the queue for longer than the defined eventFlushInterval, which is specified in milliseconds. The queue is then flushed and all queued events are sent to Optimizely in a single network request.
• A new datafile revision is received. This occurs only when live datafile updates are enabled.

For the React Native users, eventMaxQueueSize represents the maximum number of events that can be stored in the persistent cache when the device is offline.

import { createInstance } from '@optimizely/react-sdk';

const optimizely = createInstance({
  datafile: window.datafile // assuming you have a datafile at window.datafile
  // other options
  eventBatchSize: 100,
  eventFlushInterval: 3000,
  eventMaxQueueSize: 10000,
});

const optimizelySdk = require('@optimizely/optimizely-sdk')

optimizelySdk.createInstance({
  // other options
  eventBatchSize: 100,
  eventFlushInterval: 3000,
})

The table below defines these options and their default values.

❗️

Warning

The maximum payload size is 3.5 MB. Optimizely rejects requests with a 400 response code, Bad Request Error, if the batch payload exceeds this limit.

The size limitation is because of the Optimizely Events API, which Full Stack uses to send data to Optimizely.

The most common cause of a large payload size is a high batch size. If your payloads exceed the size limit, try configuring a smaller batch size.

Close Optimizely on application exit

If you enable event batching, it is important that you call the Close method (optimizely.close()) prior to exiting. This ensures that queued events are flushed as soon as possible to avoid any data loss.

❗

Important

Because the Optimizely client maintains a buffer of queued events, you must call close() on the Optimizely instance before shutting down your application or whenever dereferencing the instance.