This document describes how to configure your Google Kubernetes Engine deploymentso that you can use Google Cloud Managed Service for Prometheus to collect metrics fromMemcached. This document shows you how to do the following:

• Set up the exporter for Memcached to report metrics.
• Access a predefined dashboard in Cloud Monitoring to view the metrics.
• Configure alerting rules to monitor the metrics.

These instructions apply only if you are usingmanaged collectionwith Managed Service for Prometheus.If you are using self-deployed collection, then see thesource repositoryfor the Memcached exporterfor installation information.

These instructions are provided as an example and are expected to work inmost Kubernetes environments.If you are having trouble installing anapplication or exporter due to restrictive security or organizational policies,then we recommend you consult open-source documentation for support.

For information about Memcached, seeMemcached.

Prerequisites

To collect metrics fromMemcachedby usingManaged Service for Prometheus and managed collection, your deployment mustmeet the following requirements:

• Your cluster must be running Google Kubernetes Engine version 1.28.15-gke.2475000 or later.
• You must be running Managed Service for Prometheus with managed collection enabled. For more information, see Get started with managed collection.

• To use dashboards available in Cloud Monitoring for the Memcached integration, you must usememcached_exporter version v0.10.0 or later.

  For more information about available dashboards, seeView dashboards.

Install the Memcached exporter

We recommend that you install the Memcached exporter,memcached_exporter,as a sidecar to your Memcached workload.For information about using sidecars, seeExtended applications on Kubernetes with multi-containerpods.

To installmemcached_exporter as a sidecar to Memcached,modify your Memcached configuration as shown in the followingexample:

# Copyright 2022 Google LLC## Licensed under the Apache License, Version 2.0 (the "License");# you may not use this file except in compliance with the License.# You may obtain a copy of the License at##     https://www.apache.org/licenses/LICENSE-2.0## Unless required by applicable law or agreed to in writing, software# distributed under the License is distributed on an "AS IS" BASIS,# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.# See the License for the specific language governing permissions and# limitations under the License.apiVersion:apps/v1kind:Deploymentmetadata:name:memcachedspec:selector:matchLabels:+app.kubernetes.io/name:memcachedtemplate:metadata:labels:+app.kubernetes.io/name:memcachedspec:containers:-name:memcachedimage:ubuntu/memcached:1.6-22.04_betaports:-containerPort:11211name:memcachedprotocol:TCP+-name:memcached-exporter+image:quay.io/prometheus/memcached-exporter:v0.10.0+ports:+-containerPort:9150+name:prometheus

You must add any lines preceded by the+ symbol to yourconfiguration.

To apply configuration changes from a local file, run the following command:

kubectl apply -nNAMESPACE_NAME -fFILE_NAME

You can alsouse Terraformto manage your configurations.

Define a PodMonitoring resource

For target discovery, the Managed Service for Prometheus Operatorrequires a PodMonitoring resource that corresponds tothe Memcached exporter in the same namespace.

You can use the following PodMonitoring configuration:

# Copyright 2022 Google LLC## Licensed under the Apache License, Version 2.0 (the "License");# you may not use this file except in compliance with the License.# You may obtain a copy of the License at##     https://www.apache.org/licenses/LICENSE-2.0## Unless required by applicable law or agreed to in writing, software# distributed under the License is distributed on an "AS IS" BASIS,# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.# See the License for the specific language governing permissions and# limitations under the License.apiVersion:monitoring.googleapis.com/v1kind:PodMonitoringmetadata:name:memcachedlabels:app.kubernetes.io/name:memcachedapp.kubernetes.io/part-of:google-cloud-managed-prometheusspec:endpoints:-port:prometheusscheme:httpinterval:30spath:/metricsselector:matchLabels:app.kubernetes.io/name:memcached

Ensure that the label selectors and the port match the selectors and portused inInstall the Memcached exporter.

To apply configuration changes from a local file, run the following command:

kubectl apply -nNAMESPACE_NAME -fFILE_NAME

You can alsouse Terraformto manage your configurations.

Define rules and alerts

You can use the followingRules configuration to definealerts on your Memcached metrics:

# Copyright 2022 Google LLC## Licensed under the Apache License, Version 2.0 (the "License");# you may not use this file except in compliance with the License.# You may obtain a copy of the License at##     https://www.apache.org/licenses/LICENSE-2.0## Unless required by applicable law or agreed to in writing, software# distributed under the License is distributed on an "AS IS" BASIS,# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.# See the License for the specific language governing permissions and# limitations under the License.apiVersion:monitoring.googleapis.com/v1kind:Rulesmetadata:name:memcached-ruleslabels:app.kubernetes.io/component:rulesapp.kubernetes.io/name:memcached-rulesapp.kubernetes.io/part-of:google-cloud-managed-prometheusspec:groups:-name:memcachedinterval:30srules:-alert:MemcachedHighEvictionsannotations:description:|-Memcached high evictionsVALUE = {{ $value }}LABELS: {{ $labels }}summary:Memcached high evictions (instance {{ $labels.instance }})expr:memcached_items_evicted_total > 0for:5mlabels:severity:warning-alert:MemcachedNoConnectionsannotations:description:|-Memcached no connectionsVALUE = {{ $value }}LABELS: {{ $labels }}summary:Memcached no connections (instance {{ $labels.instance }})expr:memcached_current_connections == 0for:5mlabels:severity:warning

To apply configuration changes from a local file, run the following command:

kubectl apply -nNAMESPACE_NAME -fFILE_NAME

You can alsouse Terraformto manage your configurations.

For more information about applying rules to your cluster, seeManaged rule evaluation and alerting.

Verify the configuration

You can use Metrics Explorer to verify that you correctly configuredthe Memcached exporter. It might take one or two minutes forCloud Monitoring to ingest your metrics.

To verify the metrics are ingested, do the following:

1. In the Google Cloud console, go to theleaderboard Metrics explorer page:

   Go toMetrics explorer

   If you use the search bar to find this page, then select the result whose subheading isMonitoring.

2. In the toolbar of thequery-builder pane, select the button whose name is eithercode MQL orcode PromQL.
3. Verify thatPromQL is selectedin theLanguage toggle. The language toggle is in the same toolbar thatlets you format your query.
4. Enter and run the following query:
   

   up{job="memcached", cluster="CLUSTER_NAME", namespace="NAMESPACE_NAME"}

View dashboards

The Cloud Monitoring integration includestheMemcached Prometheus Overview dashboard.Dashboards are automatically installed when you configure the integration.You can also view static previews of dashboards without installing theintegration.

To view an installed dashboard, do the following:

1. In the Google Cloud console, go to thedashboard Dashboards page:

   Go toDashboards

   If you use the search bar to find this page, then select the result whose subheading isMonitoring.

2. Select theDashboard List tab.
3. Choose theIntegrations category.
4. Click the name of the dashboard, for example,Memcached Prometheus Overview.

To view a static preview of the dashboard, do the following:

1. In the Google Cloud console, go to the Integrations page:

   Go toIntegrations

   If you use the search bar to find this page, then select the result whose subheading isMonitoring.

2. Click theKubernetes Engine deployment-platform filter.
3. Locate the Memcached integration and clickView Details.
4. Select theDashboards tab.

Troubleshooting

For information about troubleshooting metric ingestion problems, seeProblems with collection from exporters inTroubleshooting ingestion-side problems.