Adding components

In ADCM a component means a part of a service that should be deployed on one or several cluster hosts.

IMPORTANT
Initially, there are no components on any of cluster hosts — the distribution of components between hosts should be performed manually.

The steps of adding components to hosts are listed below:

  1. From the CLUSTERS tab switch to the cluster configuring. To do this, click the row that contains the added cluster or click the icon in the Config column. Both methods open the cluster menu.

    cluster config
    Switching to cluster configuring
  2. Open the Hosts - Components tab in the cluster menu.

    NOTE
    The orange exclamation mark near the Hosts - Components menu item is displayed when the components distribution is needed.
    cluster components open
    Switching to services components distribution

    You must use an odd number of nodes for the Etcd component. Three or more nodes are recommended. You can click add hosts to add additional hosts for Etcd and other components.

  3. In the opened window, distribute all necessary components between cluster hosts. To distribute components, use one of the ways:

    • Select a component in the Components column (by clicking at it) and then define all hosts for it in the Hosts column (by alternate clicking at each host).

      cluster components type1
      Choosing hosts for a component
    • Select a host in the Hosts column (by clicking at it) and define all components for it in the Components column (by alternate clicking at each component).

      cluster components type2
      Choosing components for a host
    Mandatory and optional components

     
    Each service can have mandatory and optional components:

    • If the component is optional, it has a simple quantitative counter located to the right of its name — without the / symbol. This counter displays the number of hosts that is assigned to the current component.

    • If the component is mandatory, its quantitative counter contains the / symbol. The first digit in the counter (displayed before /) shows the current number of assigned hosts, and the second digit (displayed after /) — the minimal required number of hosts.

      cluster components mandatory
      Mandatory components

      Currently, ADPG and NTP Master components are mandatory and should be placed on one host.

      CAUTION
      Without assigning necessary count of hosts to mandatory components, the service distribution map cannot be saved.

    An example of components distribution for the ADPG Enterprise Edition is shown in the table below.

    ADPG components distribution
    Host Service Component Notes

    Host 1

    ADPG

    ADPG

    Can be a leader or replica in the HA architecture

    Chrony

    NTP Master

     — 

    Host 2

    ADPG

    ADPG

    Can be a leader or replica in the HA architecture

    Chrony

    NTP Secondary

     — 

    Host 3

    ADPG

    ADPG

    Can be a leader or replica in the HA architecture

    Chrony

    NTP Secondary

     — 

    Host 4

    Etcd

    Etcd

    You must use an odd number of nodes for the Etcd component. Three or more nodes are recommended

    Chrony

    NTP Slave

     — 

    Host 5

    Etcd

    Etcd

    You must use an odd number of nodes for the Etcd component. Three or more nodes are recommended

    Chrony

    NTP Slave

     — 

    Host 6

    Etcd

    Etcd

    You must use an odd number of nodes for the Etcd component. Three or more nodes are recommended

    Chrony

    NTP Slave

     — 

  4. After components distribution is completed, click Save.

    cluster components save
    Saving components distribution
  5. As a result, the orange exclamation mark near the menu item Hosts - Components stops being displayed.

    cluster components success
    The result of successful components distribution
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