P90 (90th Percentile) and Average return identical values for API Latency

[HenriqueRM]

Hi,

Issue
When querying my API latency metrics, the Average and the 90th percentile both return the same value. I expect the P90 to be higher than the average.

Reproduction Steps

1. In Data Explorer, add two metrics with the same API filter (my_api_service):
   • gateway.Latency → Average
   • gateway.Latency → Percentile 90th
2. Observe that both charts display the same values.
3. Run the following DQL query in Data Explorer:

Avg = avg(cloud.aws.api_gateway.latency),

P90 = percentile(cloud.aws.api_gateway.latency, 90, rollup: avg)

Expected Result
P90 > Avg

Actual Result
P90 == Avg

I’m confident that the 90th percentile should exceed the average latency. Please advise why both metrics are identical and how to correct this.

Thanks

[HenriqueRM]

I’m going through this because the new dashboard visualization doesn’t allow selecting these metrics by default.