«Host aggregates» tab

It allows to group compute hosts and manage large number of components at once such as sort, configure, add one or more groups. Compute node groups are divided into availability zones. Availability Zones are described on the page along with all compute host groups:

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List of host aggregates and availability zones

Available information about Host aggregates:
Field name Description
Name Name of the host aggregate. It is set at creation.
Availability zone Availability zone of aggregate. It is set at creation.
Hosts List of hosts that are included in this aggregate. They are added both when creating aggregate and to an already created one.
Balancing

Flag indicating the possibility of moving instances from host during balancing if there are other nodes in the availability zone. Possible values are:

  • Yes, during the balancing process, the transfer of instances is allowed;
  • No, during the balancing process, the transfer of instances is prohibited.

It can be changed in the general list.
Metadata Metadata information.

Sorting and filtering tools are available for the list of host aggregates. Fields are sorted in ascending and descending order.

Actions with host aggregates:
N Action Description
1 Create Host Aggregate Creating Host Aggregate.
2 Edit Host Aggregate Changing name and availability zone. Availability zone is set by manual input. New one can be created by entering new name, or the name of one of the existing Availability Zones can be entered. Existing Availability Zones are available for review below on the page.
3 Manage Hosts Adding or removing hosts in the aggregate.
4 Update Metadata Managing host aggregate metadata.
5 Delete Host Aggregate Deleting Host Aggregate.

Listed actions are available for execution with respect to one selected host aggregate by selecting required action in the “Actions” field of the corresponding line in the list of all host aggregates:

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Individual actions on host aggregate

You can also run actions against group of pre-selected aggregates. To do this, you need to mark the required aggregates and select group action:

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Group actions on host aggregates

Available information about Availability zones:
Field name Description
Availability Zone Name Name of zone.
Hosts Name of hosts included in the availability zone.
Available Administrative state.

Sorting and filtering tools are available for availability zones list. Fields are sorted in ascending and descending order. Filtering tool works by the name of any of fields, for example, incomplete input of the name.

Availability Zones

Availability zone is an isolated area that is used to provide fault tolerance, is the metadata of host aggregates that group computing nodes into logical clusters within which migration (including live migration) of instances is carried out, as well as auto-evacuation of machines in case of problems on one of the cluster nodes, which, together with the mechanism of host aggregates, provides fault tolerance.

Important

One Availability Zone can have multiple host aggregates, but one host can belong to only one Availability Zone.

Features of work

Adding host aggregate

In the general list on control panel using the button «Create host aggregate» open the wizard:

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Adding host aggregate window

In the window that opens, indicate:

  • Name is an optional field, if the value is empty, name is generated automatically;
  • Availability zone, the choice is made based on the need for certain resources;
  • Hosts, managing hosts in aggregates.

Follow directions on pages of the wizard to select options you want. We complete the creation procedure with button «Create node aggregator». After that, correctly created host aggregate will be displayed in the general list. Otherwise, the system will return you to the wizard window indicating reasons for the impossibility of its creation.

Updating host aggregate metadata

Function allows to manage the metadata of the host aggregate. It is available in the general list. After calling the action in the window that opens, set the necessary parameters:

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Change host aggregate metadata window

Parameters are divided into two groups: «Available metadata» and «Existing Metadata». Filtering tool is available for lists. Metadata management is carried out by buttons in the form of plus and minus.

To add new metadata use the option «Custom», input required key in the format ASCII and add it to the existing.

Complete the procedure with the button «Save».

Hosts management

Function is available only in the general list of all hosts. After calling the action in the window that opens, add or remove hosts as needed:

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Hosts management window

Save changed parameters with the «Save» button.