1. Host group function

1.1. Introduction

This document aims to explain the Exastro IT Automation Host group function.

1.2. Host group overview and merits

1.2.1. Host group overview

A host group is a group that contains hosts organized in logical units (function/roles).

The following picture is a conceptual diagram of a host group.

図 1.55 Host group overview figure

The figure above is structured with the following elements.

■Host group

Illustrated as single-line square items. Contains all, dc1, dc3, zabbix1 and zabbix3.

■Target host

Hosts indicating physical devices.

Illustrated as items with rounded squares. Contains host11, host12, host31 and host32.

Host groups can be connected with parent-child relationships. The upper host groups are called parent host groups and the lower host groups are called child host groups.

The bottom of the illustration are the devices the host groups are linked to.

In the example ebove, zabbix1 is a child host group of dc1 and zabbix is the parent host group of zabbix1.

In a hierarchy, host groups counts as 1 level and parent-child host groups counts as 2 levels. A hierarchy can contain up to 15 levels including the source host group and device host group.

The figure above contains 3 levels from "all" to "zabbix1".

1.2.2. Host group merits

1.2.2.1. Host group parameter inheritance

Paremeters set in parent host groups are inherited by child host groups.

In the figure below, the parameters set for "dc1" (e.g. user passwords) are inherited to "zabbix1".

Note that parameters will not be inherited if they dont contain specific values.

図 1.56 Host group overview figure (Host group parameter inheritance 1)

By utilizing this function to localize the settings, users can simplify changing and assigning configurations.

The parameter settings are automatically inherited, even if a new child is added after the settings are configured.

In the figure below, zabbix12 is linked to zabbix1 when a new zabbix server is added.

As a result, the zabbix1 configurations are inherited by zabbix12, just like zabbix11.

図 1.57 Host group overview figure (Host group parameter inheritance 2)

Child host groups can be linked to multiple parent host groups. This section explains parameter inheritence when there are multiple parent host groups.

In the figure below, zabbix11 and zabbix12 belongs to both zabbix1 and virtualserver.

図 1.58 Host group overview figure (Host group parameter inheritance 3)

If there are overlapping parameters between the host groups, the parameters from the lower host group will be used.

In the figure above, when both dcx and zabbix1 have configured the same parameter, zabbix11 and zabbix12 will not inherit parameters from dcx, but from the lower host group, zabbix1.

If both of the parent host groups are on the same level in the hierarchy, the host group with the highest priority level will be used.

In the figure above, if the same parameters are configured by both virtualserver and zabbix1 and the priority level of virtualserver is "1" while the priority level for zabbix1 is "2", the parameters from zabbix1 will be used, as the priority level is higher.

For more information regarding configuring priority levels, see "Host group registration".

1.3. Host group function main features

The main functions of the host group function can be divided into 2 main categories, managing host groups configurations and dividing parameter sheet host group unit records into host units.

■The following operations allows users to divide targets from all parameter sheets.

・Register/Update/Discard/Restore in the host group related menus.

- Host group list

- Host group parent-child link

- Host link management

■The following operations allows users to divide targets from only corresponding parameter sheets.

・Register/Update/Discard/Restore in parameter sheet (with host group).

・Register, Edit or Initialize in parameter sheets where "use host groups" was selected in the Define/create parameter sheets menu.

1.4. Host group function menu group

The Host group function's menu group and the belonging menus are as follows.

表 1.92 Host group function

No	Menu group	Menu/Page	Description
1	Host group management	Host group list	Registers host groups.
2	Host group management	Host group parent-child link	Links host groups in parent-child relationships.
3	Host group management	Host link management	Links host groups, operations and target hosts.
4	Host group management	Host group division target	Manages division process statuses and division target parameter sheet information.

1.4.1. "Host group management" menu group

The following menus registers host groups and defines what operation and what host should be used:

|Host group list, Host group parent-child link and Host link management. | For more information on how to operate them, see "Dividing records from host groups to host units".

1.5. Dividing records from host groups to host units

The following table shows the workflow for registering host groups and setting information for each host using Web content.

More information regarding each of the steps are found in the correspondings sections.

表 1.93 Operation contents and target menus

No	Contents	User operation	Used menu group	Used menu	Remarks
1	Parameter sheet creation	Yes	Create parameter sheets	Define/create parameter sheets	ー
2	Host group registration	Yes	Host group management	Host group list	ー
3	Host group parent^child relationship definition	Yes	Host group management	Host group parent-child link	ー
4	Host group, operation and target host link	Yes	Host group management	Host link list	ー
5	Registering to parameter sheets	Yes	※2	Menu created in ""Parameter sheet creation"	ー
6	Hostifying	No ※1	※2	Menu created in ""Parameter sheet creation"	Cannot register/update manually.
7	Setting values for items per operation and target host	Yes	※2	Substitute value auto registration settings	For more information regarding Substitute value auto registration settings, see the following. "Parameter sheet creation function" "Ansible Driver"
8	Target host linked to operation reflection	No ※1	※3	Target host	For more information regarding Target hosts, see the following. "Ansible Driver"
9	Substitute value reflection	No ※1	※3	Susbtitute value management	For more information regarding Susbtitute value management, see the following. "Ansible Driver"

注釈

※1 No user operation is required because it is executed by internal processing. Processing results can be checked on the menu screen.

※2 Menu group specified in Define/create parameter sheets.

※3 Menu group that can use Substitute value auto registration settings. For more informatio nregarding each of the steps, see the record images here: Operation contents and records

1.5.1. Operation contents and records

This section contains record images for the different menus corresponding to the steps from Operation contents and target menus.

For information, see "Operation content details".

1. Parameter sheet creation

   Target host or Host group	Operation	Item 1	Item 2
   _
   _

2. Host group registration

   Host group
   HG_1
   HG_2
   hg_1a
   hg_1b
   hg_2a
   hg_2b

3. Host group parent^child relationship definition

   Parent host group	Child host group
   HG_1	hg_1a
   HG_1	hg_1b
   HG_2	hg_2a
   HG_2	hg_2b

4. Host group, operation and target host link

   Host group	Operation	Target host
   hg_1a	OP1	host_1a
   hg_1b	OP1	host_1b
   hg_2a	OP1	host_2a
   hg_2b	OP1	host_2b

5. Registering to parameter sheets

   Target host or Host group	Operation	Item 1	Item 2
   HG_1	2023/01/01 00:00_OP1	111	AAA
   HG_2	2023/01/01 00:00_OP1	ー	BBB

6. Hostifying

   Target host	Operation	Scheduled execution date/time	Item 1	Item 2
   host_1a	OP1	2023/01/01 00:00:00	111	AAA
   host_1b	OP1	2023/01/01 00:00:00	111	AAA
   host_2a	OP1	2023/01/01 00:00:00	ー	BBB
   host_2b	OP1	2023/01/01 00:00:00	ー	BBB

7. Setting values for items per operation and target host

   Menu group: Menu name: Item name	Movement	Variable name
   Substitute value auto registration:HG parameter management:Item 1	Movement1	VAR_Variable_1
   Substitute value auto registration:HG parameter management:Item 2	Movement2	VAR_Variable_2

8. Target host linked to operation reflection

   Operation	Movement	Target host
   OP1	Movement1	host_1a
   OP1	Movement1	host_1b
   OP1	Movement2	host_1a
   OP1	Movement2	host_1b
   OP1	Movement2	host_2a
   OP1	Movement2	host_2b

9. Substitute value reflection

   Operation	Movement	Target host	Variable name	Specific value
   2023/01/01 00:00_OP1	Movement1	host_1a	VAR_Variable 1	111
   2023/01/01 00:00_OP1	Movement1	host_1b	VAR_Variable 1	111
   2023/01/01 00:00_OP1	Movement2	host_1a	VAR_Variable 2	AAA
   2023/01/01 00:00_OP1	Movement2	host_1b	VAR_Variable 2	AAA
   2023/01/01 00:00_OP1	Movement2	host_2a	VAR_Variable 2	BBB
   2023/01/01 00:00_OP1	Movement2	host_2b	VAR_Variable 2	BBB

1.5.2. Operation content details

This section explains more detailed information regarding the operation contents from Operation contents and target menus.

For record images for the operation contents, see Operation contents and records.

1.5.2.1. Parameter sheet creation

Use the Parameter sheet creation function to create a parameter sheet menu.

For more information regarding the parameter sheet creation function, see "Parameter sheet creation function".

1.5.2.2. Host group registration

Use the Host group list to register a host group.

表 1.94 Host group list registration

Item	Description	Input required	Input method	Restrictions
Host group name	Input a name for the host group.	○	Manual	Maximum length 255 bytes
Priority	Input a number for the priority level.		Manual	The input range is 0-2,147,483,647.

Tip

If no "Priority" value is input and there are multiple host groups on the same level in the hierarchy, the host group prioritized will be random.

1.5.2.3. Host group parent^child relationship definition

Use the Host group parent-child link menu to define host group's parent-child relationships.

表 1.95 Host group parent-child link registration

Item	Description	Input required	Input method	Restrictions
Parent host group	Select the name of the host group that will be the parent.	○	List selection
Child host group	Select the name of the host group that will be the child.	○	List selection

Tip

If there is a loop in the parent-child relationship, an error will occur when new registrations/updates are processed.

In the example below, "HG1(parent)"-"HG2(child)" is linked and "HG2(parent)"-"HG3(child)" is linked. Linking then "HG3(parent)" with "HG1(child)" creates a loop.

図 1.59 List/Update: error (parent-child loop)

1.5.2.4. Host group, operation and target host link

Use the Host link management menu to register the target host that will link with the host group and operation.

表 1.96 Host link management

Item	Desccription	Input required	Input method	Restrictions
Host group name	Select host group.	○	List selection
Operation	Select operation.		List selection	※1
Host name	Select the target host.	○	List selection

Tip

※1 Users register Operation as blank in the Host link management. When the operation is registered as blank, all operations will be linked.

By linking a target host with a host group and operation, the user can select target hosts within the host group like in the example below.

• Example 1

  Making the target host all hosts in a specified host group.

• Example 2

  Making only some hosts in a specified host group target host.

• Example 3

  Combining with the pattern in example 2.

• Host link management operation configuration example

In the example above, the linked host groups zabbix1 and zabbix2 where the operation is registered as blank which is valid for all operations.

On the other hand, the host group zabbix3 for which the operation has been registered is valid only for the registered operation for“OP10”

• Host group link with operation "OP10"

• Host group link with operations other than operation "OP10"

1.5.2.5. Registering to parameter sheets

In parameter sheets using host groups created in "Parameter sheet creation", register specific values for each operation to items that has either target host or target host group.

The records can be viewed/updated/discarded/restored after registration.

表 1.97 Parameter sheet (with host group)

Item	Description	Input required	Input method	Restrictions
Host name	Select target host or host group Items that starts with [H] are hosts. Items that starts with [HG] are host groups.	○	List selection
Operation name	Select operation.	○	List selection
Standard date/time	Displays the standard date/time.	-	-	Displays the standard time/date for the selected operation.
Scheduled execution time	Displays the scheduled execution date.	-	-	Displays the scheduled execution date for the selected operation.
Last executed date/time	Displays the last executed date/time	-	-	Displays the date/time of the last time the selected operation was executed.
Parameter sheet target item	Input a specific value for the item. This value will be displayed as the specific value for variables linked to the operation, movement and target host in Substitute value reflection.	※	※	※Will be the settings for the item name and item defined in the Parameter sheet creation menu.

The "Host name" and "Operation" combinations must be uniquely registered.

The same host can registered when combined with different operations.

1.5.2.6. Hostifying

The information registered in " Registering to parameter sheets" is compiled per operation by the internal "Host group dividing function" and inherited to all hosts up until the target host in the specified host group.

The information inherited by each target host can be viewed in the parameter sheet menu created in "Parameter sheet creation".

Substitute value auto registration menu group menus can only be viewed.

A standard Hostifying process is as follows.

1. The items registered to the parameter sheet menu is as follows.

   (Information registered in "Registering to parameter sheets")

   表 1.98 Information registered in "Registering to parameter sheets".

   Target host or Host group	Operation	Item 1	Item 2
   HG_1	2023/01/01_00:00_OP1	111	AAA
   HG_2	2023/01/01_00:00_OP1	ー	BBB
   host_1a	2023/01/01_00:00_OP1	222	ー

2. The host group parent-child relationship are as following.

   (Information registered in "Host group parent^child relationship definition".)

   表 1.99 Host group parent-child relationship

   Parent host group	Child host group
   HG_1	hg_1a
   HG_1	hg_1b
   HG_2	hg_2a
   HG_2	hg_2b

3. The Host group, Operation and Target host link information is as following.

   (Information registered in ""Host group, operation and target host link")

   表 1.100 Target host link information

   Host group	Operation	Target host
   hg_1a	2023/01/01_00:00_OP1	host_1a
   hg_1b	2023/01/01_00:00_OP1	host_1b
   hg_2a	2023/01/01_00:00_OP1	host_2a
   hg_2b	2023/01/01_00:00_OP1	host_2b

4. Hostifying while information is registered to (1)-(3) will create the following record contents. We can see that information is configured for target hosts belonging to the host group.

注釈

If an item is registered to both host group and target host, the target host item will be prioritized. As such, the "222" registered to "host_1a" will be applied.

While the target host item will be prioritized, if blank, it will inherit from upper levels. In this case, host1_a's Item_2 was blank, meaning that the parent host group's HG_1's "AAA" will be inherited.

host_2a and host_2b's Item_1 is blank, but that is because HG_" Item_1 is blank.

1.5.2.7. Setting values for items per operation and target host

Link menus and items that are link targets in the Substitute value auto registration menu with Movement variables. Users can Register/Update/Discard/Restore.

The registered information is reflected in the "Substitute value management" menu and "Target host" menu.

For more information, see "Parameter sheet creation".

1.5.2.8. Target host linked to operation reflection

The target host linked to the Operation is automatically reflected.

The reflected results can be seen in the "Target host" menu.

For more information, see "Parameter sheet creation".

1.5.2.9. Substitute value reflection

Specific values that are substituted to variables within Playbook templates and files used by the target movements are automatically reflected for each operation.

This specific value is the one input in this section "Registering to parameter sheets".

The reflected results can be seen in the "Substitute value management" menu.

For more information, see "Parameter sheet creation".