Creating an instance group in a placement group

If you do not have the Yandex Cloud command line interface yet, install and initialize it.

The folder specified in the CLI profile is used by default. You can specify a different folder using the --folder-name or --folder-id parameter.

1. View the description of the CLI command to create a placement group:

   yc compute placement-group create --help
   

2. Create a placement group in the default folder with one of the placement strategies:

   • Spread placement:

     yc compute placement-group create \
       --spread-strategy \
       --name <placement_group_name>
     

     Where:

     • --spread-strategy: Shows that the spread placement strategy is selected.
     • --name: Placement group name.

   • Partition placement:

     yc compute placement-group create \
       --partitions <partition_count> \
       --name <placement_group_name>
     

     Where:

     • --partitions: Shows that the partition placement strategy is selected with the number of partitions specified: from 1 to 5.
     • --name: Placement group name.

3. View a description of the CLI command to create an instance group:

   yc compute instance-group create --help
   

4. Make sure the folder contains at least one network:

   yc vpc network list
   

   If there are none, create a network.

5. Select one of the Yandex Cloud Marketplace public images, e.g., CentOS 7.

   To get a list of available images using the CLI, run this command:

   yc compute image list --folder-id standard-images
   

   Result:

   +----------------------+-------------------------------------+--------------------------+----------------------+--------+
   |          ID          |                NAME                 |          FAMILY          |     PRODUCT IDS      | STATUS |
   +----------------------+-------------------------------------+--------------------------+----------------------+--------+
   ...
   | fdvk34al8k5n******** | centos-7-1549279494                 | centos-7                 | dqni65lfhvv2******** | READY  |
   | fdv7ooobjfl3******** | windows-2016-gvlk-1548913814        | windows-2016-gvlk        | dqnnc72gj2is******** | READY  |
   | fdv4f5kv5cvf******** | ubuntu-1604-lts-1549457823          | ubuntu-1604-lts          | dqnnb6dc7640******** | READY  |
   ...
   +----------------------+-------------------------------------+--------------------------+----------------------+--------+
   

6. Create a YAML file with any name, e.g., specification.yaml.

7. In the created file, indicate the following:

   • General information about the instance group:

     name: first-fixed-group
     service_account_id: <service_account_ID>
     description: "This instance group was created from YAML config."
     

     Where:

     • name: Name of the instance group. The name must be unique within the folder. The name may contain lowercase Latin letters, numbers, and hyphens. The first character must be a letter. The last character cannot be a hyphen. The name may be up to 63 characters long.

     • service_account_id: Service account ID.

       You cannot delete a service account while it is linked to an instance group.

     • description: Description of the instance group.

   • Instance template, such as:

     instance_template:
       platform_id: standard-v3
       resources_spec:
         memory: 2g
         cores: 2
       boot_disk_spec:
         mode: READ_WRITE
         disk_spec:
           image_id: fdvk34al8k5n********
           type_id: network-hdd
           size: 32g
       network_interface_specs:
         - network_id: c64mknqgnd8a********
           primary_v4_address_spec: {}
           security_group_ids:
             - enps0ar5s3ti********
       scheduling_policy:
         preemptible: false
       placement_policy:
         placement_group_id: fdvte50kv3nc********
     

     By default, the disk size is specified in bytes. You can specify a different unit of measurement using the applicable suffix.

     Suffix	Prefix and multiplier	Example
     k	kilo- (210)	640k = 640 × 210 = 655360
     m	mega- (220)	48m = 48 × 220 = 50331648
     g	giga- (230)	10g = 10 × 230 = 10737418240
     t	tera- (240)	4t = 4 × 240 = 4398046511104
     p	peta- (250)	2p = 2 × 250 = 2251799813685248

     Where:

     • platform_id: Platform ID.

     • memory: Amount of RAM.

     • cores: Number of processor cores (vCPUs).

     • mode: Disk access mode.

       • READ_ONLY: Read-only access.
       • READ_WRITE: Read/write access.

     • image_id: ID of the public image. You can view image IDs in the management console when creating a VM or in Cloud Marketplace on the image page under Product IDs.

     • type_id: Disk type.

     • size: Disk size.

     • network_id: ID of the default-net network.

     • primary_v4_address_spec: IPv4 specification. You can allow public access to the group's instances by specifying the IP version for the public IP address. For more information, see Template description in a YAML file.

     • security_group_ids: List of security group IDs.

     • scheduling_policy: Scheduling policy configuration.

     • preemptible: Flag for creating preemptible VMs.

       • true: Create a preemptible VM.
       • false (default): Create a regular VM.

       When creating a preemptible instance group, keep in mind that the VM instances will terminate after 24 hours of continuous operation or earlier. Instance Groups may not be able to restart them immediately due to insufficient resources. This may occur in the event of a sharp increase in the use of Yandex Cloud computing resources.

     • placement_policy: VM placement group parameters:

       • placement_group_id: Placement group ID.

   • Policies:

     deploy_policy:
       max_unavailable: 1
       max_expansion: 0
     scale_policy:
       fixed_scale:
         size: 3
     allocation_policy:
       zones:
         - zone_id: ru-central1-a
           instance_tags_pool:
           - first
           - second
           - third
     

     Where:

     • deploy_policy: Deployment policy for instances in the group.
     • scale_policy: Scaling policy for instances in the group.
     • allocation_policy: Policy for allocating VM instances across availability zones.

   Full code for the specification.yaml file:

   name: first-fixed-group
   service_account_id: ajed6ilf11qg********
   description: "This instance group was created from YAML config."
   instance_template:
     platform_id: standard-v3
     resources_spec:
       memory: 2g
       cores: 2
     boot_disk_spec:
       mode: READ_WRITE
       disk_spec:
         image_id: fdvk34al8k5n********
         type_id: network-hdd
         size: 32g
     network_interface_specs:
       - network_id: c64mknqgnd8a********
         primary_v4_address_spec: {}
         security_group_ids:
           - enps0ar5s3ti********
      scheduling_policy:
        preemptible: false
      placement_policy:
        placement_group_id: fdvte50kv3nc********
   deploy_policy:
     max_unavailable: 1
     max_expansion: 0
   scale_policy:
     fixed_scale:
       size: 3
   allocation_policy:
     zones:
       - zone_id: ru-central1-a
         instance_tags_pool:
         - first
         - second
         - third
   

8. Create an instance group in the default folder:

   yc compute instance-group create --file specification.yaml
   

   This command creates a group of three similar instances with the following configuration:

   • Name: first-fixed-group
   • OS: CentOS 7
   • Network: default-net
   • Placement group: my-group
   • Availability zone: ru-central1-a
   • vCPUs: 2; RAM: 2 GB
   • Network HDD: 32 GB