flagger/docs/gitbook/usage/metrics.md

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# Metrics Analysis
As part of the analysis process, Flagger can validate service level objectives
(SLOs) like availability, error rate percentage, average response time and any other objective
based on app specific metrics.
If a drop in performance is noticed during the SLOs analysis,
the release will be automatically rolled back with minimum impact to end-users.
## Builtin metrics
Flagger comes with two builtin metric checks: HTTP request success rate and duration.
```yaml
analysis:
metrics:
- name: request-success-rate
interval: 1m
# minimum req success rate (non 5xx responses)
# percentage (0-100)
thresholdRange:
min: 99
- name: request-duration
interval: 1m
# maximum req duration P99
# milliseconds
thresholdRange:
max: 500
```
For each metric you can specify a range of accepted values with `thresholdRange` and
the window size or the time series with `interval`.
The builtin checks are available for every service mesh / ingress controlle
and are implemented with [Prometheus queries](../faq.md#metrics).
## Custom metrics
The canary analysis can be extended with custom metric checks.
Using a `MetricTemplate` custom resource,
you configure Flagger to connect to a metric provider and run a query that returns a `float64` value.
The query result is used to validate the canary based on the specified threshold range.
```yaml
apiVersion: flagger.app/v1beta1
kind: MetricTemplate
metadata:
name: my-metric
spec:
provider:
type: # can be prometheus or datadog
address: # API URL
secretRef:
name: # name of the secret containing the API credentials
query: # metric query
```
The following variables are available in query templates:
* `name` (canary.metadata.name)
* `namespace` (canary.metadata.namespace)
* `target` (canary.spec.targetRef.name)
* `service` (canary.spec.service.name)
* `ingress` (canary.spec.ingresRef.name)
* `interval` (canary.spec.analysis.metrics[].interval)
A canary analysis metric can reference a template with `templateRef`:
```yaml
analysis:
metrics:
- name: "my metric"
templateRef:
name: my-metric
# namespace is optional
# when not specified, the canary namespace will be used
namespace: flagger
# accepted values
thresholdRange:
min: 10
max: 1000
# metric query time window
interval: 1m
```
## Prometheus
You can create custom metric checks targeting a Prometheus server by
setting the provider type to `prometheus` and writing the query in PromQL.
Prometheus template example:
```yaml
apiVersion: flagger.app/v1beta1
kind: MetricTemplate
metadata:
name: not-found-percentage
namespace: istio-system
spec:
provider:
type: prometheus
address: http://prometheus.istio-system:9090
query: |
100 - sum(
rate(
istio_requests_total{
reporter="destination",
destination_workload_namespace="{{ namespace }}",
destination_workload="{{ target }}",
response_code!="404"
}[{{ interval }}]
)
)
/
sum(
rate(
istio_requests_total{
reporter="destination",
destination_workload_namespace="{{ namespace }}",
destination_workload="{{ target }}"
}[{{ interval }}]
)
) * 100
```
Reference the template in the canary analysis:
```yaml
analysis:
metrics:
- name: "404s percentage"
templateRef:
name: not-found-percentage
namespace: istio-system
thresholdRange:
max: 5
interval: 1m
```
The above configuration validates the canary by checking if the HTTP 404 req/sec percentage
is below 5 percent of the total traffic. If the 404s rate reaches the 5% threshold, then the canary fails.
Prometheus gRPC error rate example:
```yaml
apiVersion: flagger.app/v1beta1
kind: MetricTemplate
metadata:
name: grpc-error-rate-percentage
namespace: flagger
spec:
provider:
type: prometheus
address: http://flagger-prometheus.flagger-system:9090
query: |
100 - sum(
rate(
grpc_server_handled_total{
grpc_code!="OK",
kubernetes_namespace="{{ namespace }}",
kubernetes_pod_name=~"{{ target }}-[0-9a-zA-Z]+(-[0-9a-zA-Z]+)"
}[{{ interval }}]
)
)
/
sum(
rate(
grpc_server_started_total{
kubernetes_namespace="{{ namespace }}",
kubernetes_pod_name=~"{{ target }}-[0-9a-zA-Z]+(-[0-9a-zA-Z]+)"
}[{{ interval }}]
)
) * 100
```
The above template is for gRPC services instrumented with
[go-grpc-prometheus](https://github.com/grpc-ecosystem/go-grpc-prometheus).
## Prometheus authentication
If your Prometheus API requires basic authentication, you can create a secret in the same namespace
as the `MetricTemplate` with the basic-auth credentials:
```yaml
apiVersion: v1
kind: Secret
metadata:
name: prom-basic-auth
namespace: flagger
data:
username: your-user
password: your-password
```
Then reference the secret in the `MetricTemplate`:
```yaml
apiVersion: flagger.app/v1beta1
kind: MetricTemplate
metadata:
name: my-metric
namespace: flagger
spec:
provider:
type: prometheus
address: http://prometheus.monitoring:9090
secretRef:
name: prom-basic-auth
```
## Datadog
You can create custom metric checks using the Datadog provider.
Create a secret with your Datadog API credentials:
```yaml
apiVersion: v1
kind: Secret
metadata:
name: datadog
namespace: istio-system
data:
datadog_api_key: your-datadog-api-key
datadog_application_key: your-datadog-application-key
```
Datadog template example:
```yaml
apiVersion: flagger.app/v1beta1
kind: MetricTemplate
metadata:
name: not-found-percentage
namespace: istio-system
spec:
provider:
type: datadog
address: https://api.datadoghq.com
secretRef:
name: datadog
query: |
100 - (
sum:istio.mesh.request.count{
reporter:destination,
destination_workload_namespace:{{ namespace }},
destination_workload:{{ target }},
!response_code:404
}.as_count()
/
sum:istio.mesh.request.count{
reporter:destination,
destination_workload_namespace:{{ namespace }},
destination_workload:{{ target }}
}.as_count()
) * 100
```
Reference the template in the canary analysis:
```yaml
analysis:
metrics:
- name: "404s percentage"
templateRef:
name: not-found-percentage
namespace: istio-system
thresholdRange:
max: 5
interval: 1m
```
## Amazon CloudWatch
You can create custom metric checks using the CloudWatch metrics provider.
CloudWatch template example:
```yaml
apiVersion: flagger.app/v1alpha1
kind: MetricTemplate
metadata:
name: cloudwatch-error-rate
spec:
provider:
type: cloudwatch
region: ap-northeast-1 # specify the region of your metrics
query: |
[
{
"Id": "e1",
"Expression": "m1 / m2",
"Label": "ErrorRate"
},
{
"Id": "m1",
"MetricStat": {
"Metric": {
"Namespace": "MyKubernetesCluster",
"MetricName": "ErrorCount",
"Dimensions": [
{
"Name": "appName",
"Value": "{{ name }}.{{ namespace }}"
}
]
},
"Period": 60,
"Stat": "Sum",
"Unit": "Count"
},
"ReturnData": false
},
{
"Id": "m2",
"MetricStat": {
"Metric": {
"Namespace": "MyKubernetesCluster",
"MetricName": "RequestCount",
"Dimensions": [
{
"Name": "appName",
"Value": "{{ name }}.{{ namespace }}"
}
]
},
"Period": 60,
"Stat": "Sum",
"Unit": "Count"
},
"ReturnData": false
}
]
```
The query format documentation can be found
[here](https://aws.amazon.com/premiumsupport/knowledge-center/cloudwatch-getmetricdata-api/).
Reference the template in the canary analysis:
```yaml
analysis:
metrics:
- name: "app error rate"
templateRef:
name: cloudwatch-error-rate
thresholdRange:
max: 0.1
interval: 1m
```
**Note** that Flagger need AWS IAM permission to perform `cloudwatch:GetMetricData` to use this provider.
## New Relic
You can create custom metric checks using the New Relic provider.
Create a secret with your New Relic Insights credentials:
```yaml
apiVersion: v1
kind: Secret
metadata:
name: newrelic
namespace: istio-system
data:
newrelic_account_id: your-account-id
newrelic_query_key: your-insights-query-key
```
New Relic template example:
```yaml
apiVersion: flagger.app/v1beta1
kind: MetricTemplate
metadata:
name: newrelic-error-rate
namespace: ingress-nginx
spec:
provider:
type: newrelic
secretRef:
name: newrelic
query: |
SELECT
filter(sum(nginx_ingress_controller_requests), WHERE status >= '500') /
sum(nginx_ingress_controller_requests) * 100
FROM Metric
WHERE metricName = 'nginx_ingress_controller_requests'
AND ingress = '{{ ingress }}' AND namespace = '{{ namespace }}'
```
Reference the template in the canary analysis:
```yaml
analysis:
metrics:
- name: "error rate"
templateRef:
name: newrelic-error-rate
namespace: ingress-nginx
thresholdRange:
max: 5
interval: 1m
```