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To define this dependency among resources, configure this link in the ‘Resource Dependency’ view from detailed information panel of MCCS console.
[Figure] Dependency relationship
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You can simply configure the dependency link of these resources in a tree form.You can see the dependency among resources intuitively from the view above.
The IP address resource as a parent depends on the NIC resource as its child. The application resource as a parent depends on the IP address resource as its child.
Therefore, some resources as like IP address of above example can be both child and parent relatively.
As described before, When a single resource is failed MCCS failover all of the resources in a group. Therefore
Therefore, when these are linked to one another as dependency rule and tied up together as a group, they can provide proper application service.
When you configure parent-child dependency link between two resources, there are 2 levels and the maximum level can be checked on value of 'MaxDependencyLevel' of group attribute.
Link
[Figure] Setting Link
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| Warning |
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For linking process, first selected resource is parent resource and the one selected later is the child resource. |
Unlink
[Figure] Setting Unlink
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- When you unlink the dependency, select "Select" icon from the "Palette".
- Select a dependency link to delete.
- On the selected link, right click with your mouse button and select the "Unlink" button from pop up menu and click the "OK" button.
Dependency Attribute
[Figure] Edit DependancyType
You can review and edit a dependency attribute when you select a dependency among resources.
There are "OnlineDependency" and "OfflineDependency" in the dependency attribute.
This is applied when you bring online and take offline a resource within "Restartlimit"(For more details about Restartlimit, Please refer to "Chapter 7. Resource" in this manual.)
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Action by dependency attribute
- OnlineDependency
[Figure] Example of bring online of resource r1
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- MCCS check the Online Dependency attribute linked to r1.
- Child resources, r4 -> r2 -> r1, are brought online in order to hierarchy when initiate resource online of r1 due to attribute of D1 is STRONG.
(r3 isn't brought online due to attribute of D2 is WEAK.)
- OfflineDependency
[Figure] Example of take offline of resource r4
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- Failure occurs from a resource on which critical resource depend.
[Figure] Example of Failure Occur 1
- As a failure is occurred at resource r2, resource r1 will be taken offline(Since resource r1 depends on resource r2 which is failed, resource r1 may cannot be online properly).
- Since resource r2 has critical attribute, resource r3 and a4 will be taken offline in order to failover the group.
- As a result, resource r2 is considered as failure and all resources in the group will be taken offline
Non-critical Resources
[Figure] Example of Failure Occur 2
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RestartLimit is an attribute of the resource type. This value determines how many times the recovery will be attempted until it is finally confirmed that it is failure.
(Please refer to "Chapter 7. Resource" for more details.)
[Figure] Example of Failure Occur 3
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