Prometheus metrics troubleshooting on Amazon EKS and Kubernetes clusters
This section provides help for troubleshooting your Prometheus metrics setup on Amazon EKS and Kubernetes clusters.
General troubleshooting steps on Amazon EKS
To confirm that the CloudWatch agent is running, enter the following command.
kubectl get pod -n amazon-cloudwatch
The output should include a row with
cwagent-prometheus-
in
the id
NAME
column and
Running
in the STATUS
column.
To display details about the running pod, enter the following command. Replace
pod-name
with the complete name of your pod that has a name
that starts with cw-agent-prometheus
.
kubectl describe pod
pod-name
-n amazon-cloudwatch
If you have CloudWatch Container Insights installed, you can use CloudWatch Logs Insights to query the logs from the CloudWatch agent collecting the Prometheus metrics.
To query the application logs
Open the CloudWatch console at https://console.amazonaws.cn/cloudwatch/
. -
In the navigation pane, choose CloudWatch Logs Insights.
-
Select the log group for the application logs, /aws/containerinsights/
cluster-name
/application -
Replace the search query expression with the following query, and choose Run query
fields ispresent(
kubernetes.pod_name
) as haskubernetes_pod_name, stream, kubernetes.pod_name, log | filter haskubernetes_pod_name andkubernetes.pod_name
like /cwagent-prometheus
You can also confirm that Prometheus metrics and metadata are being ingested as CloudWatch Logs events.
To confirm that Prometheus data is being ingested
Open the CloudWatch console at https://console.amazonaws.cn/cloudwatch/
. -
In the navigation pane, choose CloudWatch Logs Insights.
-
Select the /aws/containerinsights/
cluster-name
/prometheus -
Replace the search query expression with the following query, and choose Run query
fields @timestamp, @message | sort @timestamp desc | limit 20
Logging dropped Prometheus metrics
This release does not collect Prometheus metrics of the histogram type. You can use the CloudWatch agent to check whether any Prometheus metrics are being dropped because they are histogram metrics. You can also log a list of the first 500 Prometheus metrics that are dropped and not sent to CloudWatch because they are histogram metrics.
To see whether any metrics are being dropped, enter the following command:
kubectl logs -l "app=cwagent-prometheus" -n amazon-cloudwatch --tail=-1
If any metrics are being dropped, you will see the following lines in the
/opt/aws/amazon-cloudwatch-agent/logs/amazon-cloudwatch-agent.log
file.
I! Drop Prometheus metrics with unsupported types. Only Gauge, Counter and Summary are supported. I! Please enable CWAgent debug mode to view the first 500 dropped metrics
If you see those lines and want to know what metrics are being dropped, use the following steps.
To log a list of dropped Prometheus metrics
-
Change the CloudWatch agent to debug mode by adding the following bold lines to your
prometheus-eks.yaml
orprometheus-k8s.yaml
file, and save the file.{ "agent": { "debug": true },
This section of the file should then look like this:
cwagentconfig.json: | { "agent": { "debug": true }, "logs": { "metrics_collected": {
-
Reinstall the CloudWatch agent to enable debug mode by entering the following commands:
kubectl delete deployment cwagent-prometheus -n amazon-cloudwatch kubectl apply -f prometheus.yaml
The dropped metrics are logged in the CloudWatch agent pod.
-
To retrieve the logs from the CloudWatch agent pod, enter the following command:
kubectl logs -l "app=cwagent-prometheus" -n amazon-cloudwatch --tail=-1
Or, if you have Container Insights Fluentd logging installed, the logs are also saved in the CloudWatch Logs log group /aws/containerinsights/
cluster_name
/application.To query these logs, you can follow the steps for querying the application logs in General troubleshooting steps on Amazon EKS.
Where are the Prometheus metrics ingested as CloudWatch Logs log events?
The CloudWatch agent creates a log stream for each Prometheus scrape job configuration.
For example, in the prometheus-eks.yaml
and
prometheus-k8s.yaml
files, the line job_name:
'kubernetes-pod-appmesh-envoy'
scrapes App Mesh metrics. The Prometheus target is
defined as kubernetes-pod-appmesh-envoy
. So all App Mesh Prometheus metrics
are ingested as CloudWatch Logs events in the log stream
kubernetes-pod-appmesh-envoy under the log group named
/aws/containerinsights/cluster-name/Prometheus.
I don't see Amazon EKS or Kubernetes Prometheus metrics in CloudWatch metrics
First, make sure that the Prometheus metrics are ingested as log events in the log group /aws/containerinsights/cluster-name/Prometheus. Use the information in Where are the Prometheus metrics ingested as CloudWatch Logs log events? to help you check the target log stream. If the log stream is not created or there are no new log events in the log stream, check the following:
-
Check that the Prometheus metrics exporter endpoints are set up correctly
-
Check that the Prometheus scraping configurations in the
config map: cwagent-prometheus
section of the CloudWatch agent YAML file is correct. The configuration should be the same as it would be in a Prometheus configuration file. For more information, see <scrape_config>in the Prometheus documentation.
If the Prometheus metrics are ingested as log events correctly, check that the embedded metric format settings are added into the log events to generate the CloudWatch metrics.
"CloudWatchMetrics":[ { "Metrics":[ { "Name":"envoy_http_downstream_cx_destroy_remote_active_rq" } ], "Dimensions":[ [ "ClusterName", "Namespace" ] ], "Namespace":"ContainerInsights/Prometheus" } ],
For more information about embedded metric format, see Specification: Embedded metric format .
If there is no embedded metric format in the log events, check that the
metric_declaration
section is configured correctly in the config map:
prometheus-cwagentconfig
section of the CloudWatch agent installation YAML file. For
more information, see Tutorial for adding a
new Prometheus scrape target: Prometheus API Server metrics.