instrumentation

var (
	// MLatencyMs records the time it took for request to be served (routed to proxy)
	MLatencyMs = stats.Float64("request/latency", "Latency of request served", "ms")

	// KeyTarget holds target information of the request being routed. It will be either "canary" or "main"
	KeyTarget, _ = tag.NewKey("target")

	// KeyReason holds information of the reason on routing decision
	KeyReason, _ = tag.NewKey("reason")

	// KeyVersion holds information of binary version
	KeyVersion, _ = tag.NewKey("version")
)

var (
	// RequestCountView provide View for request count grouped by target and reason
	RequestCountView = &view.View{
		Name:        "request/count",
		Measure:     MLatencyMs,
		Description: "The count of requests per target and reason",
		Aggregation: view.Count(),
		TagKeys:     []tag.Key{KeyVersion, KeyTarget, KeyReason},
	}

	// RequestLatencyView provide view for latency count distribution
	RequestLatencyView = &view.View{
		Name:        "request/latency",
		Measure:     MLatencyMs,
		Description: "The latency distribution per request target",

		Aggregation: view.Distribution(0, 25, 50, 75, 100, 200, 400, 600, 800, 1000, 2000, 4000, 6000),
		TagKeys:     []tag.Key{KeyVersion, KeyTarget},
	}
)