Monitoring Functions¶
The Gateway component exposes several metrics to help you monitor the health and behavior of your functions
| Metric | Type | Description | Labels |
|---|---|---|---|
gateway_functions_seconds |
histogram | Function invocation time taken | function_name |
gateway_function_invocation_total |
counter | Function invocation count | function_name, code |
gateway_service_count |
counter | Number of function replicas | function_name |
http_request_duration_seconds |
histogram | Seconds spent serving HTTP requests | method, path, status |
http_requests_total |
counter | The total number of HTTP requests | method, path, status |
The http_request* metrics record the latency and statistics of /system/* routes to monitor the OpenFaaS gateway and its provider. The /async-function route is also recorded in these metrics to observe asynchronous ingestion rate and latency.
Examples¶
These basic metrics can be used to track the health of your functions as well a general usage patterns. See the Prometheus documentation and examples for more details about the available options and query functions. Below are several queries you might want to include in a basic Grafana dashboard for observing your OpenFaaS functions
Function invocation rate¶
Return the per-second rate of invocation as measured over the previous 20 seconds:
rate ( gateway_function_invocation_total [20s])
Function replica count / scaling¶
Return the total function replicas:
gateway_service_count
Total OK Function Invocation¶
Return the total number of successful function invocations:
sum( gateway_function_invocation_total { code=\"200\"}
Function execution time¶
Return the average function execution time, as measure over the previous 20 seconds:
(rate(gateway_functions_seconds_sum[20s]) / rate(gateway_functions_seconds_count[20s]))
Metrics for a single function¶
Each of the metrics generated by the Gateway are labeled with and can be filtered by the function name, For example The invocation rate for just a single function (e.g. if the function name is echo) is given by
rate ( gateway_function_invocation_total{function_name='echo'} [20s])