Overview: Traffic Metrics
Understanding how traffic metrics are collected, aggregated, and reported.
Overview
The data that NGINX Controller collects can be divided into two categories:
- System metrics: Data collected from the NGINX Plus API, the NGINX log files, and NGINX process state.
- Traffic metrics: Data related to processed traffic, with the ability to distinguish the Application, API endpoint, or Environment that traffic is directed through.
Note:
The key difference between system and traffic metrics is that traffic metrics are pre-aggregated for each time period.
Metrics are published at a regular interval of 60 or 30 seconds for system and traffic metrics, respectively.
This topic gives an overview of the traffic metrics. Also known as “app-centric” metrics, traffic metrics contain information that lets you easily identify the App to which the data applies.
See Also:
Refer to View traffic metrics for instructions on how to view traffic metrics using the NGINX Controller REST API.
Available traffic metrics
client.latency.{total | max | min | count}
client.network.latency.{total | max | min | count}
client.request.latency.{total | max | min | count}
client.ttfb.latency.{total | max | min | count}
client.response.latency.{total | max | min | count}
upstream.network.latency.{total | max | min | count}
upstream.header.latency.{total | max | min | count}
upstream.response.latency.{total | max | min | count}
http.request.bytes_rcvd
http.request.bytes_sent
http.request.count
See Also:
Refer to the NGINX Controller Metrics Catalog for details about these and the other metrics that NGINX Controller reports.
Calculating traffic metrics
As traffic flows through a configured application, NGINX Controller collects the traffic-related data. With heavy traffic, the number of single, distinguishable metrics can be challenging to discern. For this reason, the metric values are aggregated.
The aggregation happens every publish period – this period is stored in the aggregation_duration
dimension, and is usually 30 seconds – and is based on metric dimensions.
Metrics are aggregated using four aggregation functions:
- SUM for
http.request.bytes_rcvd
,http.request.bytes_sent
and all metrics with.total
suffix. - MAX for metrics with
.max
suffix. - MIN for metrics with
.min
suffix. - COUNT for metrics with
.count
suffix.
Example
To better understand how metrics are aggregated, consider the following example:
Imagine you have one application configured with one URI (recorded in the http.uri
dimension of each traffic-related metric). In the last 30 seconds, a user queried that URI five times. The client.request.latency
values for the requests were: 1 ms, 2 ms, 3 ms, 4 ms, and 5 ms.
The final metric values returned by the Metrics API will be:
http.request.count
= 5client.request.latency.total
= 15 msclient.request.latency.max
= 5 msclient.request.latency.min
= 1 msclient.request.latency.count
= 5