Placement groups#

General information#

A placement group is a group of instances distributed across multiple physical compute nodes in one or more availability zones.

The use of placement groups guarantees that one of the duplicated instances will be available to user if a physical computing node in a data center fails.

You can run max five instances in a placement group per availability zone. For example, you can run 15 instances in a group in three availability zones (five instances per availability zone). If you attempt to start a sixth instance in the same placement group and the same availability zone, the instance will not start.

To create, change or delete placement groups, use K2 Cloud web interface or API.

Creating a placement group#

To create a placement group:

  1. Go to Virtual machines Compute Placement groups.

  2. Click Create.

  3. Specify the placement group name and (optionally) the Name tag. To assign other tags, click Add tags. If no tags are required, skip the next step.

  4. To add a tag, click Add tag and enter tag key and value.

    Note

    If no tags have been set yet, you can add the Name tag by clicking Add Name tag and specifying its value.

  5. Click Create.

The created group will be available for selection when creating or modifying an instance.

Select/change a placement group#

You can start an instance in a placement group or change the placement group in which the instance is located in one of the following ways:

  • Specify the placement group in the instance creation wizard.

  • Move the stopped instance from one placement group to another. To do this, go to the instance page, navigate to the Information tab, and edit the Placement group field.

  • Remove the instance from the placement group.

Note

You can edit or delete a placement group for stopped instances only.

Assigning tags#

To add, modify or delete placement group tags:

  1. Go to Virtual machines Compute Placement groups.

  2. In the resource table, find the placement group for which tags should be edited and click on the group name to go to its page.

  3. Open the Tags tab.

  4. To add a tag, click Add tag and specify the Key and Value fields.

    To modify a tag, edit the required fields (Value and/or Key) of the respective tag.

    To delete a tag, click the icon next to the tag you no longer need.

    Note

    If no tags have been set earlier, you can add the Name tag by clicking Add Name tag and specifying its value.

    Note

    You can also modify the Name tag in the Information tab by editing the corresponding field.

  5. Click Apply to save the changes.

Deleting a placement group#

To remove a placement group, make sure it contains no instances. You can stop all instances running in a placement group, move them to another placement group, or remove them from the group.

Select the placement group and click Delete.

Information about a placement group#

General information about the placement group can be viewed in the resource table in Virtual machines Compute Placement groups. To open the page of a particular group, click its name in the resource table in the Placement groups subsection.

The Information tab displays the main parameters of the placement group:

  • group name (Name tag);

  • number of instances included in the group;

  • instance placement strategy;

  • group state.

Here, you can modify the group name (Name tag) and delete the group.

The Instances tab displays a table with details of instances in the group:

  • instance ID;

  • instance name (Name tag);

  • state;

  • availability zone in which it is placed;

  • placement type;

  • dedicated host where the instance is running (if the instance is deployed on a dedicated host).

The Tags tab displays all tags assigned to the placemennt group. You can add new, modify existing, and delete no-longer-needed tags.