This page describes how you can use idle VM recommendations to identify and stopidle VM instances to reduce waste of resources and reduce your compute billon your projects.

• For more information on how Compute Engine generates idle VMrecommendations, seeHow detection of idle VM instances works.
• For more information on how to configure idle VM Recommender to receive moreor fewer recommendations, seeConfigure idle VM recommendations.

Before you begin

• Review thelimitations to check if your VM supports idle VM recommendations.
• If you haven't already, set upauthentication. Authentication verifies your identity for access to Google Cloud services and APIs. To run code or samples from a local development environment, you can authenticate to Compute Engine by selecting one of the following options:

  Select the tab for how you plan to use the samples on this page:

  Console

  When you use the Google Cloud console to access Google Cloud services and APIs, you don't need to set up authentication.

  gcloud

  1. Install the Google Cloud CLI. After installation,initialize the Google Cloud CLI by running the following command:

     gcloudinit

     If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity.

     Note: If you installed the gcloud CLI previously, make sure you have the latest version by runninggcloud components update.
  2. Set a default region and zone.

  REST

  To use the REST API samples on this page in a local development environment, you use the credentials you provide to the gcloud CLI.

  Install the Google Cloud CLI. After installation,initialize the Google Cloud CLI by running the following command:

  gcloudinit

  If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity.

  Note: If you installed the gcloud CLI previously, make sure you have the latest version by runninggcloud components update.

  For more information, seeAuthenticate for using REST in the Google Cloud authentication documentation.

Pricing

Idle VM recommendations are available free of charge. Using recommendationsto reduce your resource usage can result in cost savings.

Viewing idle VM instance recommendations

To view recommendations about idle VMs, use the gcloud CLI orREST.

gcloud recommender recommendations list \  --project=PROJECT_ID \  --location=ZONE \  --recommender=google.compute.instance.IdleResourceRecommender \  --format=yaml

gcloud recommender recommendations list \  --project=my-project \  --location=us-central1-c \  --recommender=google.compute.instance.IdleResourceRecommender \  --format=yaml

---content:...operationGroups:- operations:  - action: test    path: /status    resource: //compute.googleapis.com/projects/my-project/zones/us-central1-c/instances/vm-name    resourceType: compute.googleapis.com/Instance    value: RUNNING  - action: replace    path: /status    resource: //compute.googleapis.com/projects/my-project/zones/us-central1-c/instances/vm-name    resourceType: compute.googleapis.com/Instance    value: TERMINATEDdescription: Save cost by stopping Idle VM 'vm-name'.etag: '"83da314c23f634e1"'lastRefreshTime: '2020-02-24T07:56:40Z'name: projects/141732092341/locations/us-central1-c/recommenders/google.compute.instance.IdleResourceRecommender/recommendations/0e061a3a-f921-4216-b1b4-62e16942cd1aprimaryImpact:category: COSTcostProjection:  cost:    currencyCode: USD    nanos: -91533961    units: '-262'  duration: 2592000srecommenderSubtype: STOP_VMstateInfo:state: ACTIVE

GET https://recommender.googleapis.com/v1/projects/PROJECT_ID/locations/ZONE/recommenders/google.compute.instance.IdleResourceRecommender/recommendations

PROJECT_ID=my-projectZONE=us-central1-cRECOMMENDER_ID=google.compute.instance.IdleResourceRecommendercurl -H "Authorization: Bearer $(gcloud auth print-access-token)" \  -H "x-goog-user-project: $PROJECT_ID" \  https://recommender.googleapis.com/v1/projects/$PROJECT_ID/locations/$ZONE/recommenders/$RECOMMENDER_ID/recommendations

{"description" : "Save cost by stopping Idle VM`vm-name`","name": "projects/1574864402/locations/us-central1-c/recommenders/"        "google.compute.instance.IdleResourceRecommender/"        "recommendations/0fd31b24-cc05-4132-8431-ed54a22dd4f1","lastRefreshTime": {  "seconds": 1543912652},"primaryImpact": {  "category": COST,  "costProjection": {    "cost": {"currencyCode": "USD", "units": -50},    "duration": { "seconds": 2592000 }  }},"stateInfo": ACTIVE,"content":  "groups" : [    {      "operations" : [      {        "action": "test",        "resourceType": "compute.googleapis.com/Instance",        "resource": "//compute.googleapis.com/projects/my-project/"                    "zones/us-central1-c/instances/vm-name",        "path": "/status",        "value": "RUNNING"      },      {        "action": "replace",        "resourceType": "compute.googleapis.com/Instance",        "resource": "//compute.googleapis.com/projects/my-project/"                    "zones/us-central1-c/instances/vm-name",        "path": "/status",        "value": "TERMINATED"      }      ]    }  ]},"etag" : "cb0e6ac2cfc0b591"}

Interpreting the recommendation response

Each recommendation that you receive through the gcloud CLIor REST contains an operations group, with operations that you canperform in serial to apply the recommendation. Idle VM recommendationoperation groups include two operations:

1. A test operation to verify the currentstatusof the VM. For example:

    {   "action": "test",   "resourceType": "compute.googleapis.com/Instance",   "resource" : "//compute.googleapis.com/projects/my-project/zones/us-central1-c/instances/vm-name",   "path": "/status",   "value": "RUNNING" }

2. A replace operation to change thestatus of the VM. For example:

    {   "action": "replace",   "resourceType": "compute.googleapis.com/Instance",   "resource" : "//compute.googleapis.com/projects/my-project/zones/us-central1-c/instances/vm-name",   "path": "/status",   "value": "TERMINATED" }

The first operation is atest, which means that you should test that theresource is stillRUNNING. You can do this bychecking the VM state.

The second operation,replace, means that you should replace the resource'sstatus with a new value,TERMINATED. You can do that by stopping the VM,which is described below.

Applying idle VM recommendations

After you receive an idle VM recommendation and you decide that you no longerneed the instance, use theGoogle Cloud console, thegcloud CLI, orREST to stop and optionally deletethe instance.

If you stop but do not delete an instance and its disks, you still pay for itsdisks.

gcloud compute instances stopVM_NAME --zone=ZONE

POST https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/zones/ZONE/instances/VM_NAME/stop

If you're sure that the VM instance and its disks can be removed you candelete the instance.

What's next

• Learn more about how stopping, resetting, and deleting a VM instanceaffects the instance and its resources.
• Learn how toconfigure idle VM recommendations.