View and apply underutilized reservation recommendations

This page describes how you can use reservation recommendations to identify and delete underutilized on-demand reservations, so you can avoid charges for resources that you're not using.

For more information on how to configure the reservations recommender to receive more or fewer recommendations, see Configure underutilized reservation recommendations or Configure idle reservation recommendations.
Before you begin
- Review the limitations to check if your reservation supports underutilized reservation recommendations.
- If you haven't already, then set up authentication. Authentication is the process by which your identity is verified 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, then initialize it by running the following command:
    
    gcloud init
    
    Note: If you installed the gcloud CLI previously, make sure you have the latest version by running gcloud 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.
  For more information, see Authenticate for using REST in the Google Cloud authentication documentation.
View underutilized reservation recommendations

To view recommendations about underutilized reservations, use one of the following options.
Permissions required for this task

To perform this task, you must have the following permissions:
- recommender.computeRightSizeResourceRecommender.get on the project.
Complete this task using one of the following methods.
Console
1. In the Google Cloud console, go to the FinOps hub.
  
  Go to FinOps hub
  
  Under the Top Recommendations section, you can view underutilized reservation recommendations.
2. In the Top Recommendations section, click the recommendation tied to your underutilized reservations.
  
  When you click the recommendation, it shows extent of underutilization in the Insight section.
  
  The page with the details of the recommendation opens. In the Insight section, you can view the extent of the underutilization.
3. To view the details of the reservation, click View reservations.
  
  Clicking View Reservation Details shows the Utilization section, which displays the reservation size and your actual utilization.
  
  Clicking Edit enables the Configuration section, where you can set a new value for the number of VMs that better matches your intended usage.
  
  If you don't need the reservation anymore, then delete the reservation.
gcloud
To view recommendations about underutilized reservations, use the gcloud recommender recommendations list command with the --recommender=google.compute.RightSizeResourceRecommender flag:
```
gcloud recommender recommendations list \
  --location=ZONE \
  --recommender=google.compute.RightSizeResourceRecommender \
  --format=yaml \
  --project=PROJECT_ID
```
Replace the following:
- ZONE with the zone that contains reservations to list recommendations for.
- PROJECT_ID with the ID of your project.
For example:
```
gcloud recommender recommendations list \
  --location=us-central1-c \
  --recommender=google.compute.RightSizeResourceRecommender \
  --format=yaml \
  --project=my-project
```
If there are no underutilized reservations in the location, the response is empty. Otherwise, the response includes the following fields for each recommendation:
- operationGroups: groups of operations that you can perform to apply the recommendation
- description: an explanation of the recommendation
```
---
associatedInsights:
- insight: projects/953727763714/locations/us-central1-f/insightTypes/google.compute.RightSizeResourceRecommender/insights/ecf77776-4a2a-4e6e-aad2-b7f9c632e5f9
content:
operationGroups:
- operations:
  - action: remove
    path: /
    resource: //compute.googleapis.com/projects/committed-use-discount-test/zones/us-central1-f/reservations/test-reservation
    resourceType: compute.googleapis.com/Reservation
overview:
  currentReservation:
    machineType: n1-standard-1
    reservationName: test-reservation
    reservedMachineCount: '1'
    zone: us-central1-f
description: Save cost by deleting the underutilized reservation test-reservation
etag: '"aff724ab8e40e1ef"'
lastRefreshTime: '2024-06-10T07:00:00Z'
name: projects/953727763714/locations/us-central1-f/recommenders/google.compute.RightSizeResourceRecommender/recommendations/56f8ac5d-8380-4cb8-a76f-bbc270fb4b8e
primaryImpact:
category: COST
costProjection:
  cost:
    currencyCode: USD
    nanos: -199820000
    units: '-1072'
  costInLocalCurrency:
    currencyCode: USD
    nanos: -199820000
    units: '-1072'
  duration: 2592000s
priority: P2
recommenderSubtype: DELETE_RESERVATION
stateInfo:
state: ACTIVE
targetResources:
- //compute.googleapis.com/projects/committed-use-discount-test/zones/us-central1-f/reservations/test-reservation
```
Learn more about working with recommendations using Google Cloud CLI in gcloud examples.
REST
To view recommendations about underutilized reservations, make a GET request to the recommendations.list method and use the following recommendation type:
- google.compute.RightSizeResourceRecommender
The API call looks like:
```
GET https://recommender.googleapis.com/v1/projects/PROJECT_ID/locations/ZONE/recommenders/google.compute.RightSizeResourceRecommender/recommendations
```
Replace the following: - PROJECT_ID: the ID of your project. - ZONE: the zone that contains instances to list recommendations for.

The following example shows out to send a request with curl, and the associated sample response.
```
PROJECT_ID=my-project
ZONE=us-central1-c
RECOMMENDER_ID=google.compute.RightSizeResourceRecommender

curl -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
```
Example JSON response for an underutilized reservation recommendation:
```
{
  "associatedInsights": [
    {
      "insight": "projects/9531234763714/locations/us-central1-f/insightTypes/google.compute.RightSizeResourceRecommender/insights/ecf77776-4a2a-4e6e-aad2-b7f9c632e5f9"
    }
  ],
  "content": {
    "operationGroups": [
      {
        "operations": [
          {
            "action": "remove",
            "path": "/",
            "resource": "//compute.googleapis.com/projects/committed-use-discount-test/zones/us-central1-f/reservations/test-reservation",
            "resourceType": "compute.googleapis.com/Reservation"
          }
        ]
      }
    ],
    "overview": {
      "currentReservation": {
        "machineType": "n1-standard-1",
        "reservationName": "test-reservation",
        "reservedMachineCount": "1",
        "zone": "us-central1-f"
      }
    }
  },
  "description": "Save cost by deleting the underutilized reservation test-reservation",
  "etag": "\"8d5603cac8fa9342\"",
  "lastRefreshTime": "2024-06-11T07:00:00Z",
  "name": "projects/9531234763714/locations/us-central1-f/recommenders/google.compute.RightSizeResourceRecommender/recommendations/56f8ac5d-8380-4cb8-a76f-bbc270fb4b8e",
  "primaryImpact": {
    "category": "COST",
    "costProjection": {
      "cost": {
        "currencyCode": "USD",
        "nanos": -199820000,
        "units": "-1072"
      },
      "costInLocalCurrency": {
        "currencyCode": "USD",
        "nanos": -199820000,
        "units": "-1072"
      },
      "duration": "2592000s"
    }
  },
  "priority": "P2",
  "recommenderSubtype": "DELETE_RESERVATION",
  "stateInfo": {
    "state": "ACTIVE"
  },
  "targetResources": [
    "//compute.googleapis.com/projects/committed-use-discount-test/zones/us-central1-f/reservations/test-reservation"
  ]
}
```
You can find more details about each field in the Recommender API documentation.
Interpreting the recommendation response

Each recommendation that you receive through the gcloud CLI or REST contains an operations group, with operations that you can perform in serial to apply the recommendation. For underutilized reservations, the operation groups include a remove operation to delete the reservation:
```
{
  "action": "remove",
  "path": "/",
  "resource": "//compute.googleapis.com/projects/committed-use-discount-test/zones/us-central1-f/reservations/test-reservation",
  "resourceType": "compute.googleapis.com/Reservation"
}
```
Apply underutilized reservation recommendations

Based on underutilized reservation recommendations, either adjust the reservation size or delete the reservation if you no longer need it.

What's next
- Learn more about how Compute Engine reservations work.
- Learn how to configure underutilized reservation recommendations.
- Learn how to configure idle reservation recommendations.

View and apply underutilized reservation recommendations

Before you begin

Console

gcloud

REST

View underutilized reservation recommendations

Permissions required for this task

Console

gcloud

REST

Interpreting the recommendation response

Apply underutilized reservation recommendations

What's next