Impact Criteria

You can specify the criteria that will be used to apply an outage to a CMDB item if one or more CMDB items linked to this item are currently experiencing an outage.

Example Scenario

For example, Server X is linked to Router A, Router B and Router C. You can configure the circumstances in which an outage on Router A, Router B and/or Router C will result in an outage on Server X.

Setting Impact Criteria

Before you start

Track availability must be enabled for the CMDB item.

1. In the Explorer pane, expand CMDB Item, then select Impact Criteria.

2. The Impact Criteria window appears.

3. In the Default Behavior section, select your default preferences for the item. This is the default impact if linked item(s) experience an outage.

4. If you choose different impacts for specific linked items/groups in the Behavior by Linked Group section, the default behavior will be overwritten.

ANY linked CMDB Items experience outages	Select to cause an outage if any CMDB item impacting the current CMDB item experiences an outage. In the example, an outage on ANY of Router A, Router B or Router C will result in an outage on Server X
ALL linked CMDB Items experience outages	Select to cause an outage only if all CMDB items impacting the current CMDB item experience an outage. In our example this would mean that Router A, Router B and Router C would need to experience an outage for it to result in an outage on Server X.

1. In the Behavior by Linked Group section, select from the following:

Add a linked group	to create a group of linked items that will impact the current CMDB item
Update group details	to update an existing group's details
Add items to a group	to add further CMDB items to an existing group
Set outage criteria for linked groups	to set the impact of an outage within the linked group on the current CMDB item

1. Select to save the details.

Adding Linked Groups

Before you start

You must have CMDB Item Link Update selected in the CMDB Items tab of your Configuration Management security role.

1. In the Explorer pane, expand CMDB Item, then select Impact Criteria.

2. The Impact Criteria window appears.

3. Beneath the Behavior by Link Group section, select Add.

4. In the Select Link Group window, there are three groups included by default - Exchange Server Farm, Email Service and Network Router Farm. To select any of these groups, double-click or use the select button . This will add the group to the Configured Link Groups on the Impact Criteria page.

5. The Select Link Group window appears, listing all existing outage link groups. Select .

6. In the New Link Group window, specify a name and then select Ok.

7. The Impact Criteria window appears, with the group in the Configured Link Groups section. An additional section appears called Link Group Details, in which you can add items to the group and set the outage impacts.

8. If you do not link any items to the group, it will not be displayed in the Configured Link Groups section when you next log in. You will have to select the Add button to display the CMDB Outage Link Groups window to see it.

9. Select to save the changes. Provide the Change Reasons if prompted to do so.

10. The Select and Add options will return you to the main Impact Criteria window when completed. The other options will leave the Select Link Group window open. To return to the Impact Criteria page from the Select Link Group window, select Cancel.

11. To change the name of any of the link groups, select .

12. To delete a group, select Delete .

13. Any link groups you have added will now be displayed in the Configured link Groups table.

14. To delete groups from this table, select Delete.

Adding CMDB Items to a Link Group

Before you start

You must have CMDB Item Link Update selected in the CMDB Items tab of your Configuration Management security role.

The CMDB item must already have links to the other CMDB items.

The link group must be added to the CMDB item.

1. In the Explorer pane, expand CMDB Item, then select Impact Criteria.

2. The Impact Criteria window appears.

3. In the Configured Link Groups table, select the Link Group to which you want to add items. The details are displayed in the Linked Items List table lower in the window. You may need to scroll down to see this.

4. Select Add Link from beneath the Linked Item List table.

5. In the Select CMDB Link window, select the item you want to add to the group, either by double clicking or highlighting it and selecting . (You can select multiple items by using the Shift or Ctrl keys.)

6. Any linked items you have selected will now be displayed in the Linked Items List table.

7. Select to save the changes. Provide the Change Reasons if prompted to do so.

Setting Outage Behavior for Link Groups

You can set the behavior that will result in an outage for Link groups. This will override the behavior that you set in the Default behavior section.

1. In the Explorer pane, expand CMDB Item, then select Impact Criteria.

2. The Impact Criteria window appears.

3. In the Configured Link Groups table, select the Link Group for which you want to configure impact behavior.

4. Under Link Group Details, select one of the following:

5. ANY linked CMDB Items experience outages	to create an outage if at least one member of the Link Group is unavailable
   ALL linked CMDB Items experience outages	to create an outage only if all members of the Link Group are unavailable
   Outage score threshold reached	to create an outage based on whether the threshold score is reached.

6. Select to save the changes. Provide the Change Reasons if prompted to do so.

Defining an Outage for a Link Group based on a Threshold

You can allocate a weight or score to each link in the Link Group by defining a threshold. This means that an outage will only be created against the current CMDB item if the specified threshold value is exceeded. For example:

A server in a networked environment may be connected to three switches. This server is partially dependent on the switches, and will be available as long as two out of the three switches are functioning. To configure this, you can create a link between the server and the routers and (using a relationship called “Network Server” for each link), and assign a score of, say, 50 to each link. When two switches are unavailable the outage score is calculated as 100, and the server will be unavailable when this happens. Therefore, the outage on the server will occur when the total links score reaches 100. Only those link scores are included that have the same relationship name. An outage occurs if the total score from all the links pointing to it reaches 100. The total outage score for an item is set to 100, by default. The total outage score for the main item is calculated by adding the outage scores on the links to that item. When the total outage score from the links adds up to 100, the main item will have an outage on it.

1. In the Behavior by Link Group section, select a Link Group from the list of configured link groups.

2. In the Link Group Details section, select Outage Score threshold reached.

3. Specify a value in the Threshold field (the default value is 100).

4. Specify a score for each item in the group by selecting the Score column of the Linked Items List table and inputting the required score.

An outage can only be created against the current CMDB item if the sum of all the scores assigned to the unavailable linked CMDB items meets the threshold.