FFM-11022 Applies standard Metrics Enhancements

[erdirowlands]

What

• Splits evaluation and target metrics into their own caches:

  • so that we can track target metrics correctly. Due to the fact we use the globalTarget , this meant that we would miss targets if the evaluation didn't change.
  • Implements limits: Evaluation metrics to 10K unique evaluations--where a unique evaluation is flag + variation--this allows for evaluation for 10k flags with 5 variations each
  • Target metrics for 100K unique targets

• Implement seen targets:

  • ensures that the metrics service only gets sent target metrics for a target once, for the lifetime of the SDK instance
  • ensures that the SDK processes truly unique targets fairly, and that old targets don't occupy the 100K limit set per interval

Testing

• Metrics accuracy:
  • TestGrid metrics tests
  • Manual sample app
  • Non-anonymous targets appear in UI
  • Anonymous targets don't appear in UI
• SeenTargets:
  • The same target won't be sent on the next interval if it is evaluated against
• Limits:
  • Sent 101K unique targets, only 100K get processed

[knagurski]

Just some comments/suggestions to help with maintainability. No blockers

[knagurski]

I THINK you can set these as static. Will make zero difference, but ¯_(ツ)_/¯

[knagurski]

TOTALLY not an issue, but instead of creating a variable and then using a forEach to push to that variable. You can just swap to map and assign in one.

Suggested change

	clonedEvaluationAnalytics.forEach((event) => {
	const metricsData: MetricsData[] = clonedEvaluationAnalytics.map((event) => {

[erdirowlands]

I like 🚀 thanks.

[erdirowlands]

Dang - the map function isn't available on Map types. I'd need to convert clonedEvaluationAnalytics to an array. I'll opt to leave it as is. But in principle I agree with the functional style here.

[knagurski]

Ah man... annoying. You could spread into an array or use Array.from. Don't worry about it, it's fine as-is.

Suggested change

	clonedEvaluationAnalytics.forEach((event) => {
	const metricsData: MetricsData[] = [...clonedEvaluationAnalytics.values()].map((event) => {

[knagurski]

Same here. Also totally a non-issue.

Suggested change

	clonedTargetAnalytics.forEach((target) => {
	const targetData: TargetData[] = clonedTargetAnalytics.map((target) => {

[knagurski]

If you do want to keep as a forEach/push, then you might as well just inline this.

Suggested change

	const td: TargetData = {
	identifier: target.identifier,
	name: targetName,
	attributes: targetAttributes,
	};
	targetData.push(td);
	targetData.push({
	identifier: target.identifier,
	name: targetName,
	attributes: targetAttributes,
	});

[erdirowlands]

Done